ملخص البحث :

Jiamusi highway prestressed concrete bridge is located in the Jiamusi City within Heilongjiang province in the east north of China. The strengthening and repairing of the bridge structure can be provided an effective and economic solution in appropriate situation. The objective of this study are to monitor the construction process of external prestressing tendons for strengthening of Jiamusi highway prestressed concrete bridge. Monitoring process includes measurement of external prestressing tendons natural frequency, monitoring of tensile forces values of external prestressing tendons, monitoring of development of anchor beams cracks, and monitoring of anchor beam deformation. The results of monitoring process show that the box girder No. 11 has the largest values of proportional coefficient (K) and the maximum value is 327.8. Box girder No. 8 has the largest values of frequency, the maximum value is 3.499. Five levels of tension are used in the application of tensile force in the tension process of external prestressing tendons. These levels are level 1=248.2kN, level 2=496.4kN, level 3=744.6kN, level 4=992.8kN, and level 5=1241kN. The measured tendons elongation values of left box girder No.8 are more than the theoretical values. For left and right box girder No. 9, side external tendons of left box No. 10, and left and right box girder No. 11, the measured values are less than theoretical values of elongation. After tension process, there are no new cracks in the top, web, and bottom of anchor beam and a small number of cracks developed slightly. These cracks are found around ducts of external tendons. The length of cracks rang from 0.03m to 0.5m and width rang from 0.05 mm and 0.25mm. The longitudinal deformation of the interface and top of anchor beam is very small, ranging from 0.001mm to0.115mm, which averaged 0.026mm. The overall state of anchor beams and box girders during strengthening is good.

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Jilin highway concrete bridge is located in the center of Jilin City, which is positioned in the middle and southern part in Jilin province in east north of China. This bridge crosses the Songhua River. The strengthening of concrete bridge structure involves upgrading of the strength and stiffness of structural members, and the repair process involves reestablishing the strength and function of the damaged members. The main objectives of this study are to identify the damaged members of Jilin highway concrete bridge structure and to explain the application of strengthening and repair methods to improve the performance of the bridge structural members. The results of damages investigation of a bridge structure appearance show that the most components of the bridge are in good conditions with the exception arch waves, spandrel arch, deck pavement of the new arch bridge, and corbel of the old simply supported beam bridge which suffer from serious damages. In this study, jacketing method, grouting repair method, patching method, and replacement of expansion joint and drainage system had been used to strengthen and repair the damaged members of Jilin highway concrete bridge. After completing the strengthening and repair processes, the state of arch waves, spandrel arch, and deck pavement is good, but there is need to evaluate the performance of structural members which are strengthened and repaired by adopting static and dynamic load tests, and monitoring the development of cracks.

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Hashuang bridge is type of prestressed concrete box girder oblique bridge and it is located in Harbin City within Heilongjiang province in the east north of China. The objectives of this study are to investigate the appearance of the bridge structure and identify all the damages in the bridge structural members and to evaluate the structural performance of the bridge structure under dead and live loads. Finite element analysis is used to analyze the static designed internal forces and dynamic responses by adopting SAP200 software Ver. 14.2.0. Static and dynamic load test are adopted to evaluate the structural performance of the bridge structure. The results of field investigation process of the bridge appearance show that the bridge suffers from serious damages. The web of box girder of the second span near pier No.2 (in the quarter of middle span at 39m on the bridge length) suffers from serious shear cracks. The state of abutments, piers and sidewalks is good, but the bearing, drainage holes, steel rail and expansion joints are not good and they suffer from much damage. The steel rail is corroded and the expansion joint loses the material which fills the joint. There are many dusts and debris is collected on the bridge deck in the location near sidewalk. The analysis results of finite element and load tests show that there are high tensile stresses in the quarter of middle span at distance 39 m of the bridge length and the state of the bridge structure is not good and the main problem of the bridge structure in the original design of prestressed tendons. Therefore, this study recommends for repairing and strengthening the bridge structure to increase the stiffness and strength and to improve the bearing capacity of the bridge structural members to increase the service live of the bridge structure.

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Prestressed concrete segmental box girder bridges are composed of short concrete segments that are either precast or cast in situ and then joined together by longitudinally post-tensioning internal, external, or mixed tendons. The objectives of this study are to monitor the construction process of the external prestressing tendons to strengthen the bridge structure and perform a field load test to measure the strain and the deflection of the anchorage devices of the external prestressing tendons to determine the state of these devices after tension forces are applied. The monitoring process of the external prestressing tendons construction includes inspecting the cracks in the diaphragm anchorage and the deviation block devices before the tension forces are applied to the external tendons; measuring the deformation of the steel deviation cross beam during the tension process; measuring the deformation of the box girder after different levels of tension forces are applied; measuring the elongation of the external tendons in each level of the tension; and measuring the natural frequency of the external tendons after the tension process is complete. The results of the monitoring process show that the measured values of the deformation, the elongation, and the natural frequency meet the requirements. Therefore, there is no damage during the construction and the tensioning of the external prestressing tendons. A field load test is performed to the anchorage beam, the steel deviation block devices, and the steel deviation cross beam. The field load test results of the anchorage devices show that the values of the strains, the stresses, and the deflection are less than the respective allowable limit values in the requirements. Therefore, the anchorage devices have sufficient strength, and the working state is good after the tension forces are applied to the external prestressing tendons.

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The aim of this study is to select the suitable shape of girder cross section that is used in the design of bridges structure, and to evaluate the effect of cross section shape of bridges girders on the static properties such as vertical displacement, vertical shear force, bending moment, tension stress and compressive stresses. Ten bridges models using different types and shapes of girders were used to study the effect of girder cross section shape in the construction of bridges by adopting static analysis. The results of finite element analysis showed that the bridges models of separated concrete deck over girders have higher value of vertical displacement, positive bending moment, and tensile stress. These models are not suitable for design of bridges that subjected to higher traffic loads because of these bridges structures will not have enough stiffness and higher carrying capacity. Therefore, they will fail under heavy traffic loads. These models include flat slab bridge model, T-girder bridge model, I-girder bridge model, and steel I-girder bridge model. Most box girders bridge models appeared the lower values of vertical displacement, positive bending moment, and tensile stress. Therefore, these models will have enough stiffness and carrying capacity and they will be more elasticity from others models. This study recommended that using the box girders bridges models in the construction of new bridges structure that have high traffic loads.

ملخص البحث :

Jiamusi prestressed concrete highway bridge is located in the Jiamusi City within Heilongjiang Province in the north east of China. The application of external prestressing tendons for strengthening of existing bridges has been used in many countries since the 1950s and has been found to provide an efficient and economic solution in a wide range of the bridge types and conditions. The objectives of this study are to explain the strengthening process by using external prestressing tendons, test and analyze the anchor beams of Jiamusi prestressed concrete highway bridge. Three field tests are adopted in this study. These tests are concrete compressive strength test of anchor beams, tensile test of anchor beam re-bars, and tensile test of anchor beams structure and external prestressting tendons. The results of field tests and analysis of anchor beams and external prestressing tendons show that the value of longitudinal deformation is equal to 0.02 mm and the value of lateral strain ranges from 5 to 1 0 :g. This indicates that the anchor beams have sufficient bending stiffness and the bending capacity of anchor beam is good. The measured and theoretical values of elongation of external prestressing tendons are consistent and the values of tensile force of external tendons are less than the design tensile force (1250 kN).

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Fu Feng highway prestressed concrete bridge is located in Changchun City which is the capital and largest city of Jilin province and it located in the northeast of China. The strengthening of the bridge structural members can be attempted by replacing poor quality or defective materials by better quality materials, attaching additional load-bearing materials, and re-distribution of the loading actions through imposed deformation on the structure system. The objectives of this study are to explain the strengthening process of damaged structural members of Fu Feng bridge, and to evaluate the performance of the bridge structure by adopting static load test. The strengthening process of damaged structural members includes three stages. These stages include the strengthening of box girders floor by casting of 10cm of reinforced concrete in the floor of box girder within the location of positive bending moment in the mid-span and edge span, the strengthening of box girders web by pasting steel plates in the inside of the right and left of box girders, and the strengthening of the transverse beam of piers No. 18 and No. 19 by using carbon fiber sheet. The results of static load test show that the values of testing coefficient ( ) of stress range from 0.83 to 0.92 are less than allowable value 1.05. Therefore, these values satisfy the allowable value of standard, indicating that the structural member has a certain strength reserve and the working state of the bridge structure in good state. the ratio between the measured and theoretical deflection is 1.41 and 1.68 for condition 3 more than allowable value 0.8, indicating that the state of stiffness is not good and there are still a serious shortage in stiffness of structure. Therefore, this study recommended that the bridge structural members need to re-strengthen by using other effective technical and materials to increase the stiffness of structural members of the bridge.

ملخص البحث :

Jiamusi prestressed concrete highway bridge is located in the Jiamusi City within Heilongjiang Province in the north east of China. The application of external prestressing tendons for strengthening of existing bridges has been used in many countries since the 1950s and has been found to provide an efficient and economic solution in a wide range of the bridge types and conditions. The objectives of this study are to explain the strengthening process by using external prestressing tendons, test and analyze the anchor beams of Jiamusi prestressed concrete highway bridge. Three field tests are adopted in this study. These tests are concrete compressive strength test of anchor beams, tensile test of anchor beam re-bars, and tensile test of anchor beams structure and external prestressting tendons. The results of field tests and analysis of anchor beams and external prestressing tendons show that the value of longitudinal deformation is equal to 0.02 mm and the value of lateral strain ranges from 5 to 1 0 :g. This indicates that the anchor beams have sufficient bending stiffness and the bending capacity of anchor beam is good. The measured and theoretical values of elongation of external prestressing tendons are consistent and the values of tensile force of external tendons are less than the design tensile force (1250 kN).

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The objectives of this study are to explain the repairing and strengthening methods which are used to improve the structural performance of the bridge structure, to analyze the static and dynamic responses after strengthening, and to evaluate the performance of the bridge structure after repairing and strengthening. The methods of repairing and strengthening include reconstruction the deck of the bridge by casting 10 cm layer of concrete, strengthening the web and bottom floor of box girders of middle spans and side spans by sticking the steel plates, strengthening the whole bridge structure by using external pre-stressing tendons, and treatment the cracks. The results of theoretical analysis show that the values of tensile stress and vertical deflection are decreased and the compressive stress is increased after strengthening. There are not tensile stresses are appeared in the sections of the bridge structure. The modal analysis results show that the value of natural frequency is equal to 2.09 Hz which is more than the values before strengthening which is equal to 1.64 Hz, indicating that the stiffness of the bridge structure is improved and the strengthening process is effective to improve the cracks resistance and bearing capacity of the bridge structure. This is a preview of subscription content, access via your institution.

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Joints between segments in cantilever casting concrete bridges require special attention in design and construction. These joints introduce discontinuity in the bridge; furthermore weaken the connection stiffness and strength of corresponding section, which may lead to excessive downwarping of bridge. Experiments were conducted to assess the shear stiffness of segmental joints section. The parameters studied included monolithic non-joints, joints roughened, joints roughened with shear-key. It was found that the shear stiffness of jointed section is largely lower than that of non-jointed section; however, the shear-key can effectively enhance the shear strength and especially shear stiffness of the joints section. Measures are proposed for shear-key design, and may provide a rational basis for the design of cantilever casting concrete bridges.

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The objective of this study is to analyze the temperature and shrinkage stresses of the mid-span cross-section of a 20 meters box girder to find the reasons which cause the longitudinal cracks in the web and bottom of box girder. According to the results of damage inspeation, there are many longitudinal cracks in the web and bottom slab of box girders, especially the web of the edger beam, the crack is very clear. Ansys ver.10 software is used to analyze two dimensional finite element model of a typical cross section of a real bridge to calculate the temperature stresses caused by temperature difference between inside and out side of the box and the shrinkage stresses based on moisture diffusion. The results of analysis show that the outer surface of the web and bottom slab of the fabricated box girder will produce tensile stress at the effect of negative temperature difference. If the concrete reaches a certain age, the tensile stress does not cause creaks in the cross-section. The shrinkage stress changes with the moisture gradient in the box section. It will reach the maximum in 15 days and then decreases with the growth of the age. Shrinkage stress may cause cracking of the concrete surface because of the tensile strength is low in the early age.

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The objective of this study is to calculate and analyze the internal forces under designed dead and live loads to evaluate the structural performance of corbels and T-shaped cantilever structure of the main span of Jiamusi highway prestressed concrete bridge to evaluate the state of the structural members of the bridge. Two software are used in this analysis. The first software is Dr. Bridge Ver. 2.95 which is used to analyze the internal forces of T-shaped cantilever structure under different load combinations. The second software is Ansys Ver. 10 which is used to analyze the internal forces in the corbel. The results of analysis show that at the dead load stage, the maximum compressive stress at the upper and bottom edge of all sections of T-shaped cantilever structure satisfies the allowable values of standard. The tensile stress doesn’t appear. At the normal service stage, there is enough reserve of compressive stress in the all sections, and the compressive stress is smaller than the allowable value of the standard. There is no tensile stress for all the controlled sections. The maximum main compressive stress and maximum main tensile stress of all controlled sections is smaller than the allowable value of standard. The bending strength of all sections satisfies the allowable values of standard, and there is big reserve of strength. The steel settled in the oblique section of 45° in the web of the corbel has enough reserve for the tensile strength. If the prestressed steel in the corbel is inefficient, the resistance of the oblique section given by the ordinary steel in the corbel and it can be resisted the loads. The longitudinal positive stress of vertical section a-b, vertical shear stress, main tension stress and main tension stress of oblique section a-c of 45 satisfy the allowable values of standard.

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The main purpose of damage inspection of the bridge components is to ensure the safety of a bridge and to identify any maintenance, repair, or strengthening which that need to be carried out. The essential damages that occur in reinforced concrete bridge include different type of cracks, scalling and spalling of concrete, corrosion of steel reinforcement, deformation, excessive deflection, and stain. The main objectives of this study are to inspect the appearance of Jiamusi highway prestressed concrete bridge and describe all the damages in the bridge structural components, and to evaluate the structural performance of the bridge structure under dead and live loads. The field tests that are adopted in this study are the depth of concrete carbonation test, compressive strength of concrete test, corrosion of steel reinforcement test, and static load test. According to inspection of the bridge structure appearance, the overall states of bridge structure in good and there are not serious damages, but there are diagonal and longitudinal cracks in the inside web of box girder within block No.8 and 9. Expansion joints suffer from serious damage such as deformation of expansion joint rubber, dislocating, shedding, and cracking. The field test results show that the concrete of the bridge structure has not carbonation; the strength of concrete in good state; there is not corrosion in steel reinforcement; The values of load test for vertical deflection, strain, and stress are less than the theoretical values and the results of cracks observation show that there is not changing in the length of diagonal cracks in the web of box girder when the load test is applied. This indicates that the working state and carrying capacity of the bridge structure in good state.

ملخص البحث :

Ha Shuang Bridge is located in Harbin city within Heilongjiang province in the east north of China. The purposes of this study are to monitor the damage in structural members of Ha Shuang prestressed concrete box girder oblique bridge before strengthening and to evaluate the dynamic performance of the bridge structure by adopting dynamic load test. Monitoring process of damage of the bridge structure shows that the web of box girder in the quarter of the second span (about 10.5m from the pier) suffers from serious shear cracks. These cracks extend from the top to lower flange of box girder. The width of cracks rang from 0.5mm to 2mm and the angle is 45 degree. There are 6 bending cracks. The spacing between these cracks rang from 20cm to 30cm and the width is 035mm. In the span No. 3 near the pier, the web of box girder appears 12 diagonal cracks have width rang from 0.1mm to 0.12 mm. The results of dynamic load test analysis show that the values of measured vertical natural frequency is w1 = 3.616Hz and horizontal natural frequency w2 = 4.492Hz less than the values of theoretical natural frequency which is 3.863Hz and 4.848Hz, indicating that the actual stiffness of the bridge structure is less than the theoretical stiffness. Therefore the dynamic working state of bridge structure is not good. Therefore the working state of bridge is not good and it need to repair and strengthening.

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Longtan truss-arch concrete bridge is located near the mountain of Longtan in the east of Jilin City in the east north of China. This bridge crosses the Songhua River. The damages inspection of the bridge structure must be taken each member to evaluate the structural performance. The main objectives of this study are to inspect and classify the damages of Longtan truss-arch concrete bridge structural members, to determine the compressive strength of concrete, corrosion of steel reinforcement, to check the leveling of deck, and to evaluate the structural performance of the bridge structure members. Ansys ver. 10 software was used to analysis the internal forces. The field tests adopted in this study are: (a) compressive strength of concrete test, (b) corrosion of steel test, and (c) static load test. These tests are used to evaluate the state of a bridge structure. The results of the appearance investigation and field tests show that the bridge structure state is in good, but piers and arch rings suffer from cracks, reinforcement steel corrosion, and spalling of concrete. The results of static load test show that the deflection, strain, and cracks development meet the requirements under test loads. Therefore, this study recommended the repair and strengthening of damaged members of Longtan truss-arch concrete bridge.

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Precast prestressed concrete double tee is an economic bearing element which can be preparedinto a large span to coverage large area. Self-weight of the beam and overlay slabs or finishing layersconsidered a major part of the load carried by prestressed concrete beams. If all or part of the beam can bemanufactured using lightweight concrete, there is a prospective for economic savings because its self-weightcould be reduced up to 20%. This research paper represent a comparison between double tee beam madefrom lightweight concrete vs. normal weight in the basic of designing issues for its major aspects. The studybased on the section adopted by the Precast/Prestressed Concrete Institute, and a parametric analysis carriedout to predict a design guide for both lightweight and normal weight section. Load-span charts obtained andrecommended to used with clear way to show the effect of reducing the total weight of the section by usinglightweight concrete. Then the effect extend to include the camber at erection and long-time camber. Ingeneral the variation of load bearing capacity of the section raised much more for lightweight with respect tonormal weight concrete. Also, better response in its camber behavior shown at both stages (at erection up tolong-time). (7) (PDF) Nonlinear Analysis Comparison to Predict Design Charts for Normal and Lightweight Prestressed Concrete Double Tee Beams. Available from: https://www.researchgate.net/publication/341105717_Nonlinear_Analysis_Comparison_to_Predict_Design_Charts_for_Normal_and_Lightweight_Prestressed_Concrete_Double_Tee_Beams [accessed Mar 29 2023].

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Hot mixture asphalt was applied in the erection of different types of flexible pavement for the most of highways in the world. With the development of industries and the prosperity of the world’s economic situation and the increase in trade movement and increasing traffic loads on highways, the flexible pavement surface suffered from structural problems then the pavement will suffer from failures. Therefore, there is needing to improve the hot mixture asphalt to resist the heavy traffic loads and environmental conditions. The objective of this study is to evaluate and improve the properties of hot mixture asphalt by using date palm fibers powder as additive material by application of some experimental works and theoretical calculations. The results showed that the using of date palm fibers powder will help to decrease the percentage of different types of voids in hot mixture asphalt and improve the density of mixture. The stability results were increased when using the date palm fibers powder comparing with normal hot mixture asphalt. Also flow values were improved.

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Horizontal layout bend was an important factor in the design of bridges structure depending on nature of bridgelocation within construction area. The aim of this study was to evaluate and optimize the different designs of bridgehorizontal layout bends and compare the results with horizontal layout straight of bridge by depending on the applicationof static analysis according to finite element analysis method. Static analysis results showed that the straight model had theminimum values of static internal forces. Therefore, this model gave higher resistance to effects of applied loads and thehorizontal layout straight of this type of bridges was suitable for design (7) (PDF) HORIZONTAL LAYOUT BEND OF BRIDGES STRUCTURE EFFECTS ON THE STATIC DESIGN INTERNAL FORCES: EVALUATION AND OPTIMIZATION STUDY. Available from: https://www.researchgate.net/publication/339915918_HORIZONTAL_LAYOUT_BEND_OF_BRIDGES_STRUCTURE_EFFECTS_ON_THE_STATIC_DESIGN_INTERNAL_FORCES_EVALUATION_AND_OPTIMIZATION_STUDY [accessed Mar 29 2023].

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The objectives of this study are to evaluate the optimum design of tendon profile layout, to study the effect oftendon profile layout on the structural performance of post-tensioned concrete bridge model, and to investigate thelocations effect of anchorages points of tendons on the vertical deflection. There were four factors were selected such asbending moment, shear force, stress, and vertical deflection. According to supports of tendons, there are two cases ofbridges models. The first case is used simply-supported tendons profile layout. The second case is adopted continuoustendons profile layout. According to profile layout of tendons, the first case consists of seven bridge models (7-Models)and the second case includes ten bridge models (10-Models). The results of FEM analysis showed that the tendon profilelayout had important effect on the structural performance of post-tensioned concrete bridges according to types andnumber of anchorages points of tendons. For pre-stressed load stage, simply-supported tendon profile model appearedmaximum value of upward vertical deflection (3mm) was more than continuous tendon model (2mm). The maximumdownward vertical deflection is 12mm within continuous tendon model which is less than value of simply-supportedtendon model (13mm). According to service load stage analysis, continuous tendon model had the minimum value ofdownward vertical deflection (14mm) was more than simply-supported tendon model (15mm), but maximum value ofdownward vertical deflection was appeared in simply-supported tendon model (27mm) was more than the maximum valueof downward vertical deflection (26mm) within continuous tendon model. It can be concluded that continuous tendonprofile model was convenient for design of post-tensioned concrete bridge because it can be resisted service loads and hadthe lower value of vertical deflection.

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The objective of this research is to study the effect of adding Styrene Butadiene Styrene polymer SBS as a modifier on the mechanical properties of asphalt binder and hot mixtures asphalt (HMA) and to compare between the properties of the modified and unmodified asphalt binder and hot mixture asphalt (HMA) which is used in the rehabilitation of Baghdad province and Al-Basra province highway by paving the surface course of highway for areas suffers from problems such as rutting and cracks. There are two stages were used in the laboratory tests on asphalt binder and hot mixture asphalt (HMA). The first stage is used laboratory tests without using SBS polymer with asphalt and the second stage is used SBS Polymer with asphalt as an additive material. The results of asphalt binder tests show that the using of SBS Polymer with asphalt binder lead to improve the mechanical properties of asphalt binder. According to penetration test, the grade of asphalt is decreased from 61 and 62 to 39. The flash point, the ductility, and viscosity are increased and the solubility is decreased. The results of hot mixture asphalt test show that the adding of SBS polymer lead to improve the mechanical properties of modified hot mixture asphalt. Therefore, the Marshall stability for modified hot mixtures asphalt is increased for all samples. Therefore, the resistance to plastic flow and the load carrying capacity is improved by approximate more than 60%. The others Marshall properties such as Marshall flow, Marshall density, and Marshal air voids are improved. Therefore, the recommendation of this study is to use the modified hot mixture asphalt that is using Styrene Butadiene Styrene polymer SBS in the paving of new flexible pavement layers and in rehabilitation of the surface course of the old flexible pavement.

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The purpose of this study is to assess the influence of girder cross-sectional shapes that is using in the design of prestressed concrete bridge girders and steel bridge girders on the dynamic parameters such as natural vibration frequency, moving load vibration frequency, dynamic displacement in three dimensions, dynamic acceleration in three dimensions, and dynamic moment, and dynamic stresses. The results of the dynamic analysis show that model No.6 (box girder with external web curved) has a value of natural vibration frequency (13.38Hz) is more than the maximum value of moving load vibration frequency (13.25Hz) within model No.6 (box girder with external web curved model). This mean, model No.6 has enough stiffness, elasticity, and bearing capacity. Model No.7 (box girder with external web vertical model) has the maximum value of natural vibration frequency (13.42Hz) which is more than the all values of moving load vibration frequency of others models, indicating that model No.7 has a higher value of bearing capacity and elasticity. For other dynamic parameters, the box girders shapes appear minimum values of dynamic displacement, dynamic acceleration, dynamic moment, and dynamic tensile stress. Therefore, the box girders shapes are more suitable to design bridges structures.

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The purpose of this study is to investigate and evaluate the effect of prestressing tension force on the static responses such as vertical deflection and vertical shear force of prestressed concrete bridges. Simply-supported I-girder bridge model and continuous box girder concrete bridge model are selected. Each model is used 12 levels of prestressing tension force ranged from 500kN to 6000kN. Finite element analysis method is used in static analysis. The results of static analysis shows that simply-supported bridge model appears the maximum value of upward deflection (18mm) due to prestressing force stage and maximum value of downward deflection (-15mm) due to service loads stage. Therefore, the prestressing tension force has significant effect to reduce the downward deflection due to service loads. This model also appears direct proportion between prestressing tension force and vertical shear force for prestressing force analysis and service loads stages. For continuous box girder bridge model, the prestressing tension force has no important effect on the upward vertical deflection due to prestressing load stage and it appears just downward vertical deflection. Therefore, this types of model needs to increase the prestressing force tension of steel tendons to reduce the downward deflection and to increases upward deflection. Continuous box girder bridge model gives opposite proportion between prestressing tension force and vertical shear force in positive and negative area within prestressing force analysis stage. Under service load stage, the positive and negative vertical shear force is decreased when the prestressing tension force increased.

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The objective of this study is to evaluate the construction methods of connection area between bricks walls and concrete columns. Damage inspection process was used to discover the damages in selected buildings. According to construction method, four buildings were selected as a case study. According to damage inspection results, the building without tooth edge (building B) and the building with bonding bars (building C) were appeared cracks with different widths and lengths. For building B, the maximum width and length of crack is equal to 3.5mm and 3.25m respectively. For building C, The maximum crack width is equal to 5mm with length 3m.The buildings with tooth edge connection have no cracks in the area between bricks walls and concrete column because of the strong correlation between the concrete of column and the spaces of bricks (tooth edges). The tooth edge method of building construction did not appear cracks. Therefore, this study recommends to use the method of tooth edges in the construction of building in Iraq to prevent the cracks.

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Pier of bridge is usually used as a general term for any type of substructure located between horizontal spans and foundations. Piers give vertical supports for spans at intermediate points and perform two main functions. The objective of this study is to inspect the effect of piers shape on the dynamic structural performance by adopting theoretical dynamic analysis. The results of dynamic analysis of 25 bridges models show that the maximum value of natural frequency is equal to 5.64Hz in two circles piers bridge model. Therefore, this type of model has good stiffness and bearing capacity. The two square piers model, the one circle pier model, and the two circles piers model appear good stiffness because of the natural frequencies (5.30Hz, 5.52Hz, and 5.64Hz) are more than the maximum forced frequencies (4.52Hz, 5.45Hz, and 4.52Hz) respectively. According to the comparison between all models results, the two circles piers model has the higher stiffness because of this model has the maximum value of natural frequency (5.64Hz) and it is more than all forced vibration frequencies of all others models. Therefore, this study recommends that using the bridge model of two circles piers in the bridges construction that consists of three spans (30m+40m+30m) with section of box girder

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In order to accurately calculate the deflection of damaged concrete beam strengthened with basalt fiber reinforced plastics (BFRP) and provide theoretical foundation for the design and construction of the beam, according to different reinforcement ratios, eleven test beams with different amounts of strengthened BFRP sheet and loading methods were designed.The loaddeflection curves of different test beams were obtained.Under different pre-loading programs, the changing rules of deflection of un-strengthened beams, strengthened beams with one layer and two layers of BFRP sheet were analyzed respectively.The calculation formulas of mid-span deflection of damaged concrete beam strengthened with BFRP were presented, and the calculated deflections and measured values were compared.Analysis result indicates that the deflections of damaged concrete beams strengthened with BFRP are influenced by initial load and amount of BFRP sheet layer.The deflections of strengthened beams with initial load increase by 30%-94%compared with strengthened beams without initial load, and the deflections of strengthenedbeams with two layers of BFRP sheet increase by 19%-42% compared with strengthened beams with one layer of BFRP sheet.The impact of post-strain of BFRP should be considered in deflection calculation.The average value of the maximum difference between the calculated deflection and measured value is 7.26 mm.When the initial load is small and the reinforcement ratio is high, the calculated deflection of concrete beam is closer to the measured value, and the method can be used in the engineering practice.

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Skewed bridges are normally used to crossroadways, waterways, or railways that are not perpendicular tothe bridge structure at the intersection. It is required when it isoften not possible to arrange that a bridge spans square to thefeature that it crosses, particularly where it is important tomaintain a relatively straight alignment of a roadway above orbelow the bridge. The pier shape has important effect on thestructural performance of the bridge structure according to thelocation conditions. The main aims of this study are to select theoptimal design of piers shape and skew angles in the prestressedbox girder bridge, to study the effects of pier shape and skewangles on the static structural responses. There are 120 bridgemodel are used in this study. FEM of SAP2000 Ver. 14.0.2 isused in the analysis. The results of structural analysis show thatthe pier shape and skew angle has significant effects on the staticresponses of the bridge structure. For vertical displacement, theoptimal models are skew angle of bridge structure is range from36 degree to 54 degree and the solid rectangular pier (skewabutments and skew piers). The models of two square piers (skewabutments and without skew piers) and 48 skew angle is theoptimal models for bending moment. For tensile stress, themodel of skew angle 48 degree and the model of solidrectangular pier (skew abutments and skew piers) is the optimalmodel. It can be concluded that the skewed models gives goodresults than straight model.

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The objectives of this paper are to explain the application of repairing and strengthening methods on the damaged members of the bridge structure, to analyze the static and dynamic structural response under static and dynamic loads after strengthening, and to evaluate the structural performance after application of strengthening method. The repairing and strengthening methods which are used in this study include treatment of the cracks, thickening the web of box girder along the bridge length and adding internal pre-stressing tendons in the thickening web, and construct reinforced concrete cross beams (diaphragms) between two box girders. The results of theoretical analysis of static and dynamic structural responses after strengthening show that the tensile stresses are decreased and become less than the allowable limit values in the codes. The values of vertical deflection are decreased after strengthening. The values of natural frequencies after strengthening are increased, indicating that the strengthening method is effective to reduce the vibration of the bridge structure. Therefore, the strengthening methods are effective to improve the bearing capacity and elastic working state of the bridge structure and to increase the service life of the bridge structure.

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The main purposes of this study are to assess the influences of vehicle types and loads on the structural performance of concrete and steel bridges by using the finite element method of SAP2000 software. Two methods of analysis are adopted. The first and second method is static and dynamic analysis respectively. The results of static analysis shown that HB-AH1 vehicle is the heavy vehicle, which was passed on the bridges structures and it can be caused higher bending moment and vertical displacement. Whereas, Hn-44 vehicle is the light vehicle comparing with other types of vehicles. Concrete slab bridge produced the maximum value of vertical displacement and concrete box girder bridge appeared minimum value of vertical displacement. The results of dynamic analysis illustrated that concrete slab bridge model had natural frequency (3.52 Hz), which was less than dynamic frequency (4.64 Hz), indicating that bridge model had not enough stiffness and elasticity. Therefore, this type of bridge structure was not suitable to carry heavy traffic loads. The dynamic frequency of steel bridge model was 4 Hz. This value was less than a natural frequency value (6.82 Hz), showing that the bridge model had suitable stiffness and elasticity. Concrete bridge model had 8.58 Hz of natural frequency, which was more than dynamic frequency (4.12 Hz), resulting that bridge structure has enough stiffness, elasticity, resistance for loads, and bearing capacity. This study recommended that using concrete box girder bridges model in the building of bridges structures.

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In this study, the properties of Iraqi hot asphalt mixture which is used in highway pavement construction in Iraq are evaluated by depending on the specification requirements of Asphalt Institute 1997(USA). Marshall mix design method is used to determine the optimum asphalt content. Seven specimens of hot asphalt mixture were prepared at different asphalt contents at 1% increments from specimen to another. The results show that the hot asphalt mixture does not meet the specification requirements of Asphalt Institute 1997. Therefore, this mixture need to adjust the properties or redesign by using new amount and type of aggregate and asphalt.Keywords: Aggregate, Asphalt mixture, Asphalt properties, Marshal test, Mineral filler, Pavements.

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A Structure of wastewater treatment plant is a facility in which a combination of various processes (e.g., physical, chemical and biological) are used to treat wastewater and remove pollutants. Almost the design of wastewater treatment plant structure include two or more stages of construction, based on the capacity of the plant that its related mainly to the income sewage calculated for the population of the city at that time. Future works including many structures that will increase the capacity of the plant on the same area. That’s will need to connect the new structures to the main system by pipe lines and channel. The objectives of this research are to study the connection process and activation of new structure and old structure of wastewater treatment plant, to provide an advice to the method of connection and carry out that connection experimentally with the engineers supervised that works, and to inspect and record the structural information for six months after complete the connection and starting the works with the future structures. The proving the accuracy of adopted method was done by nondestructive test carried out before and after the connection works. The results of construction and inspection shown that the new constructed concrete appears good compressive strength which is reached to 47.45 MPa that will be factored to increase the durability of concrete that being in touch with sewage.

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The objective of this study was to assess the seismic performance of two types of bridges structures under effect of earthquake by using different locations and numbers of piers. The results of D/C ratio showed that simply supported I girder bridge appeared higher structural capacity than continuous box girder bridge which was resisted the seismic demand. Continuous box girder bridge had higher seismic demand and lower structural capacity comparing with simply supported I girder bridge. Commonly, the seismic design for two types of bridges models with increasing of piers numbers was suitable to resist the earthquake action for region type B. The results of non-linear static analysis (pushover method) showed that the increasing of piers numbers had significant effects on the seismic design of bridges structures to increase the displacement capacity, force capacity, and decreasing of seismic demand to reduce the effects of earthquake action on the bridges structural members. The bridge type simply supported I girder had higher capacity in longitudinal direction than continuous box girder bridge. Whereas, for continuous box girder bridge appeared higher capacity in transverse direction than simply supported I girder. The performance points which were based on displacement were decreased with increasing the piers numbers for bridges structures supports.

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The results of linear static analysis explained that the increasing of pier heights was leaded to rise the values of positive bending moment, tensile stresses, and downward vertical deflection. Whereas the compressive stresses and negative bending moment were decreased, indicating that the structural performance of bridge structure representing by stiffness, bearing capacity of structural members, and elasticity will decrease and the bridges structures will be damaged. Therefore, the bridges structures need safe design when using tall piers by adopting high quality materials such as high strength concrete, more steel reinforcement, more prestressed tendons, and increasing of cross section dimensions of girders and piers. The results of modal analysis show that the un-loaded dynamic frequency for three types of bridges models were decreased when the pier heights were increased, indicating that the stiffness of bridges structure was became low with higher pier height. According to response spectra and time history analysis results, the loaded dynamic frequency (vibration state) and dynamic displacement were increased when the pier heights were increased, showing that the bridge of structure will suffer from high vibration when the pier height was high. It can be concluded that from this study, the piers heights have significant effects on the static and dynamic structural performance of bridges structures under traffic loads.

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The aim of this research is to study the effects of different rates of super-elevation and on the static and dynamic internal forces by using finite element analysis methods. The methodology of this study includes the selecting of suitable bridge model, different rates of super-elevation, static and dynamic analysis by using finite element method. The analysis is carried out by using SAP2000 Ver.14 program. The results of static finite element analysis of bending moment, axial force, and shear force, shown that there is not important effect of super-elevation rates increasing on the static properties of bridge models. The positive bending moment is increased with increasing of super-elevation rates until rate 8%. The maximum value is 35998 kN.m within model has 6% of super-elevation rate and the minimum value of positive bending moment is 35194 kN.m in model that has 0% of super-elevation. For negative bending moment, model of 0 % superelevation rate has the maximum value which is 37548 kN.m and the minimum value is 35967 kN.m. For vertical deflection due to service load, the models have 0%, 2%, and 4% of super-elevation appear the lower value of vertical deflection that equal to 7.7 mm and the models have 6%, 8%, 10%, and 12% of superelevation give the higher value of vertical deflection which is equal to 7.9 mm. The values of vertical deflection due to prestressed tendons are decreased from 12 mm to 11 mm, when the super-elevation rates are increased. Therefore, the increasing of super-elevation rates had effect on the upward vertical deflection due to loads of prestressed tendons. Modal analysis results show that the increasing of super-elevation rates has not effect on the natural and the values of natural frequency are 3.07 Hz for all models of bridge structure. The most values of vibration frequency in X and Y directions are less than values of natural frequency, but in Z-direction, the values of natural frequency are less than traffic vibration frequency values, indicating that the increasing of super-elevation rates have significant effect on the dynamic properties and it will lead to decrease the stiffness of bridge structure. Other’s vibration parameters such as vibration displacement and vibration acceleration are not affected by increasing of superelevation rates

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The evaluation of structural safety must be taken after each earthquake. The importance losses of life and materials carries the significance of the works in the field of earthquake engineering. The purpose of this study was to optimize and evaluate the earthquake resistance of bridge piers by adopting different cross-section forms and dimensions for bridge supports under earthquake action. Two methods of seismic design were used in the optimization and evaluation process. These methods were demand to capacity ratio (DCR) and yielding point. The results of demand to capacity ratio shown that the values of DCR for all piers forms models were increased when the dimension of pier cross section were increased and the values of DCR became less than 1.0, indicating that the increasing in dimensions leading to rise the capacity of bridge supports to carry the earthquake loads in transverse and longitudinal direction. Comparing with models, solid wall pier form had the lower value of DCR, indicating that solid wall piers were suitable in the design of bridge supports to resist the lateral loads of earthquake and it has enough stiffness and capacity under earthquake action. The results of performance points shown that the yielding points were increased when the dimensions of piers were increased for all piers form in transverse and longitudinal direction. The maximum values were appeared within support No. 1 and support No. 4. Solid wall form of pier had the higher values of yielding points, meaning that this type of piers form had higher seismic capacity and it will resist the earthquake action more than others piers form. This study recommended that to use third model for each pier form in the design of bridges structures to resist the earthquake load. Also this study was recommended to use solid wall piers as supports in construction of bridge structure within areas had earthquake action.

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The purposes of this study were to provide a methodology for comparing between structural members of composite bridge due to flexure and shear load rating. Also it was used to evaluate and determine the load capacity of composite bridge structural members by adopting load rating analysis method through using different types of international trucks. CSI bridge Ver. 20 was used in the analysis process. The results of flexure and shear, load rating shown that the left and right girders carried the higher values of flexure and shear load rating for all types of trucks load. The structural member of bridge which was subjected to higher values of flexure and shear load rating had sufficient live load carrying capacity, more elasticity and stiffness, indicating that the values of static structural parameters such as bending moment, vertical shear force, vertical displacement and axial force were lower than structural member had minimum values of flexure load rating. The results of factored bending moment, vertical shear force, and axial force shown that truck type LM3-3600/240 had the higher values of factored bending moment, vertical shear force, and axial force within exterior girders which were appeared minimum flexure load rating. The minor values of factored bending moment, vertical shear force, and axial force were happened under effect of truck type AML and Hsn-44L because of these trucks had higher flexure and shear load rating. The maximum value of vertical displacement was 29 mm under truck type LM3-3600/240 which had lower flexure load rating.

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Particularly, concrete material involvements creep under a continuous load and practices shrinkage due to variations in humidity proportion. These physical properties variations growth over time. Prestressed losses according to concrete creep and shrinkage will lead to loss of compression strength for concrete. Time-dependent analysis is important and essential for two types of prestressed concrete which are pretensioned and posttensioned with the effect of time, variations in the structural pattern, and high erection loads influence the structural performance and protection of structure for the duration of erection and when complete. Creep and shrinkage are the main time-dependent parameters of concrete. They are important parameters in the design of prestressed concrete structures such as bridges. The objective of this study is to review the analysis models of time-dependent parameters for prestressed concrete bridges by using shrinkage and creep factors equations to determine the strain of time-dependent parameters. Creep and shrinkage parameters were selected to review the effect of these parameters on the properties of prestressed concrete. Nine analysis methods for creep and shrinkage of concrete were reviewed in this study. These models include ACI-209 model, PCI-BDM model, CEB-FIP-90 model, AASHTO-LRDF model, Shams and Kahan model, NCHRP-496 model, B3 model, GL2000 model, and AFREM model. It was recommended that using this methodology to determine shrinkage and creep factors for prestresssed concrete bridge and comparing between the results of analysis models.

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Piers were important structural members between superstructure and foundation of bridge which were designed to transfer and resist the vertical loads and horizontal loads (dead load of structure, traffic loads, water pressure, ice, and wind) to the foundation. The objective of this study was to evaluate the effect of number of piers in transverse direction (horizontal distance or spacing) between piers on the static and dynamic responses for two types of bridges structure which they include continuous and simply supported bridges. Static and dynamic analysis methods were adopted to analyse the bridges structures by using CSI-bridge software. The results of static analysis for two types of bridges models (continuous and simply supported) showed that the increasing of piers numbers had significant effects on the increasing of bridge structure stiffness by decreasing the downward vertical deflection due to service loads, increasing of the resistance of prestressed loads to service loads, and increasing of compression stresses. The results of time history analysis for two types of bridges models showed that the values of natural frequency were increased when the piers numbers were increased. Traffic load frequency (vibration frequency) values were decreased with increasing of bridge piers number because of the bridge structure had more stability. It can be concluded that the values of natural frequency were more than values of traffic load frequency, indicating that the bridges structures had enough stiffness and stability.

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The main objective of this study is to compare the structural members capacity between different types of bridges structures under seismic load. The results of seismic modal analysis showed that the models of box girder bridge, precast T girder bridge, and U steel girder bridge had the higher values of natural frequency comparing with others bridges structures under seismic load. Pushover analysis in transvers direction showed that bent No. 2 of bridges structures which was located in the middle of bridges superstructure was displaced in transvers direction more than bent No. 1 and bent No. 3. In longitudinal direction, Precast I girder bridge had higher value of longitudinal displacement comparing with others bridges structures, and it was more than the maximum value of transvers displacement. The results of demand and capacity ratio showed that bent No. 2 was the critical structural member which had values of demand/capacity ratio more than 1.0 or near from it especially precast I girder bridge, precast T girder bridge, and U steel bridge, indicating that these types of bridges will be subjected to failure in bent No. 2. Therefore, there was needing to redesign the bents of these types of bridges by increasing the numbers of piers, using high strength materials in construction of bents, and increasing of dimensions of piers and pier caps. The results of internal forces showed that bent No. 2 was subjected to the maximum values of axial force, horizontal shear, and bending moment for all types of bridges structures. Also, it can be seen that the models of precast I girder bridge, precast T girder bridge, and U steel bridge had the higher values of forces comparing to others models, indicating that these results agree with results of demand/capacity ratio and pushover analysis method.

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Layout line of bridge structure is a direction line which is used to define the horizontal and vertical alignment of the bridge structure. The objective of this study is to evaluate and optimize the different designs of bridge horizontal outline turn and compare the results with horizontal layout straight of bridge using dynamic analysis according to finite element analysis method. Dynamic analysis results showed that most models have converging values of dynamic natural frequency except Model No. F. and it explains that the higher rate of natural frequency is 5.10Hz within model No. F. The maximum value of loaded frequency is equal to 6.35 Hz for model No. I (Straight - curve right - straight - curve left - straight). Model No. A appears minimum value of loaded frequency which equal to 3.56Hz. The higher value of loaded frequency indicates that the bridge model has high vibration state which effects on the stiffness and flexibility of bridge structure. Model No. I appears higher value of downward acceleration which is 3.55m/s2. The maximum value of upward and downward deflection is 1.84mm and 4.07mm respectively in model No. G, indicating that this model will easy to deflect under traffic loads. It can be concluded that The bridges models No. F, H, I have values of loaded frequency higher than the values of natural frequency. Therefore, these models have lower stiffness and flexibility and bearing capacity than other. Therefore, this study recommended that the optimum design which has high stiffness and more elasticity.

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The objective of this study was to improve level of transit service of public transport bus routes in Baghdad city through the implementation of some remedial actions. Eight public transport bus routes were selected to evaluate and improve the Level of Transit Service (LOTS). These routes represent Al-Tahrir bus network (A) which was located in the center of Baghdad city (capital of Iraq). The suggested remedial actions include reduction of legal bus stops delay (B), the elimination of illegal bus stops delay (b), the elimination of signalized intersections delay (I), and the reduction of traffic congestion delay (C). These suggested remedial actions are leaded to improve the values of total delay, bus travel time, service frequency (headway), adjusted running speed, and capacity. The values of level of transit service for these transit performance measures were improved. The overall routes level of transit service were improved for bus routes No. (72, 36, 13, 114, 11, 30, 37, and 9) from LOTS (D, E, E, E, E, D, E, and E) to LOTS (C, D, C, D, D, C, D, and D) respectively. The overall network LOTS was improved from LOTS (E) to LOTS (D), indicating that the application of the suggested remedial actions was effective and suitable to improve the performance and Level of Transit Service for public transport bus routes in Baghdad city. Therefore, this study recommended to use the remedial actions which proposed by authors to improve level of transit service for others bus networks.

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The aim of this study is to evaluate the structural performance of digester tanks structure in Al-Jazeera sewage treatment plant within Dhi Qar province in the south of Iraq by adopting the experimental field tests and finite element analysis. Due to the significance of anaerobic digester structure, it is necessary to evaluate structural performance on a regular basis using damage inspection techniques and non-destructive tests, depending on the construction materials used to construct the structure of the digester tanks. The surface of the reinforced concrete walls of the digester tanks had numerous small cracks, and some compressive strength readings were lower than the design value, showing that there was a reduction in the safety factor of the structure, necessitating the application of modified action to enhance the structural performance of the digester tanks structures rather than the project's designer providing more safety factor. To increase the safety factor and structural performance of digester tanks, this study recommends utilizing a strengthening strategy that comprises building an additional reinforced concrete circle ring on the external walls of tanks in the top, middle, and bottom locations.

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Structure of diaphragm was defined as a transverse strengthener beam which was located between beams or girders to keep section geometry. It plays a significant role to provide the stability of bridge girders and to distribute the vertical and axial loads. The main objective of this study was to investigate the influence of construction transverse concrete diaphragms between T-beams at different distances on the dynamic and static behavior of T-beam bridge structure. The methodology of this research includes five case studies. The first case had no transverse diaphragms, the second case had transverse diaphragms at the supports of the bridge (abutment and piers), the third case had transverse diaphragms at the center of each span of the bridge, the fourth case had transverse diaphragms at 1/4 of each span of the bridge, and the fifth case had transverse diaphragms at 3 m of each span of the bridge. Three analysis methods were used to determine the dynamic responses by using finite element analysis method in CSIBridge ver. 20. These methods included modal analysis, time history analysis, and spectra responses analysis. Dynamic responses consisted of unloaded frequency, loaded frequency, and dynamic displacement. Static analysis was done to find static responses such as bending moment and vertical deflection. The results of dynamic analysis shown that the using of concrete diaphragms has not important effect on the improvement of unloaded frequency (natural frequency) in vertical and horizontal directions, but they had an important effect on the reducing of loaded frequency (vibration frequency) in vertical and horizontal direction and dynamic displacement. For static state, the construction of concrete diaphragms causes to increase bending moment and downward vertical deflection because of these cross diaphragms lead to increase in the dead load (self-weight of structure), resulting the increasing in the static responses due to service loads (dead load, prestressed load, and trucks load). Therefore, there is need to increase the prestressed load to resist the over load due to the construction of transverse diaphragms.

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A bridge can serve as a primary link between highways, railroads, crossroads, two river margins, and between mountains. The design, advancement, and global building of bridges are among the most fascinating and significant achievements in civil engineering. Bridges must be designed and built to be secure, effective, and cost-effective. Evaluation of the bridge structure is a topic that is becoming more and more important in the decision to address the deterioration of the bridge structure. To determine the actual strength of the bridge structure, its service life, and the real load scale, appropriate design and analysis procedures must be adopted. The main purpose of this study is to review the structural performance evaluation, damage inspection processes, different types of damages, static and dynamic analysis, and related studies to evaluate the structural performance of bridge structures.