Master's thesis deals with the reinforcement and expansion of girder bridge (continuous bridge with three spans) across the river Jihlava in Ivančice and reinforcement on the load class A. This is done by using an additional external prestressing cables and composite monolithic slab. Amplification is verified by calculation of load capacity.

Diploma thesis is focused on design of road bridge bearing structure over road in Jihlava. The construction is girder with 3 fields beard by local supports. Calculations were made in the program called Scia Engineer. Appraisals were made by hand.

As part of the Long Term Bridge Performance (LTBP) Program, a single-span, prestressed, integral abutment concrete girder pilot bridge near Perry, Utah was instrumented with different sensors at various locations onto the bridge for long-term monitoring and periodic testing. One of the periodic tests conducted on this bridge was a live-load test. The live-load test included driving trucks across the bridge, as well as parking trucks along different lanes of the bridge, and measuring the deflection and strain. The data collected from these tests was used to create and calibrate a computer model of the bridge. The model was afforded the same dimensions and characteristics as the actual bridge, and then the boundary conditions (how the bridge is being supported) were altered until the model data and the live-load data matched. Live-load distribution factors and load ratings were then obtained using this calibrated model and compared to the AASHTO LRFD Bridge Design Specifications. The results indicated that in all cases, the AASHTO LRFD Specification distribution factors were conservative by between 55% to 78% due to neglecting to take the bridge fixity (bridge supports) into account in the distribution factor equations. The actual fixity of the bridge was determined to be 94%.Subsequently, a variable study was conducted by creating new models based on the original bridge for changes in span length, deck thickness, edge distance, skew (angle of distortion of the bridge), and fixity to see how each variable would affect the bridge. Distribution factors were then calculated for each case and compared with the distribution factors obtained from the AASHTO LRFD Specifications for each case. The results showed that the variables with the largest influence on the bridge were the change in fixity and the change in skew. Both parameters provided ranges between 10% non- conservative and 56% conservative. The parameter with the least amount of influence was the deck thickness providing a range between 4% non-conservative and 19% non- conservative. Depending on which variable was increased, both increases and decreases in conservatism were exhibited in the study.

As part of the Long-Term Bridge Performance (LTBP) program, a flagship research program funded by the Federal Highway Administration in response to the aging bridge network, the Lambert Road Bridge near Elk Grove California was selected as the California Pilot bridge set to undergo non-destructive testing and monitoring. The purpose of the program is to obtain a database of scientific quality data concerning the health and maintenance procedures currently in use across the nation. FHWA program managers along with members of the Utah State University LTBP research team selected the bridge with the assistance of the National Bridge index and site visits. Dynamic modal analysis and long-term health monitoring are two of the test procedures that the test bridge will undergo. Dynamic modal analysis is performed by introducing a known vibration into the system and recording the response. The dynamic properties are extracted in this manner, which allows any changes in the structure to be tracked over time as the dynamic properties change. The long-term health monitoring of the bridge will include an array of sensors designed to capture the real-time structural response of the bridge under normal operating conditions at key locations. An array of 1-Hz Velocity Transducers was used to record the bridge response to the introduced vibrations. The data collected over 4 days of testing was analyzed using the "peak picking method" to locate the resonant frequencies, mode shapes, and damping ratios of the structure. In this thesis the dynamic testing results and the finite element model were compared and correlated both visually and with a modal assurance criterion. The long-term health monitoring is also discussed in this thesis. The types and reason for each sensor are presented and the installation procedure is explained and documented.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22757号 / 工博第4756号 / 新制||工||1744(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 五十嵐 晃, 教授 高橋 良和, 准教授 古川 愛子 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

American Association of State Highway and Transportation Officials (ASHTO) specifications have prescribed lateral load distribution factors to calculate the bending moments and shear forces for the design of highway bridges for civilian highway traffic. The maximum bending moments and shear forces caused by a wheel line load (or the entire vehicle) placed on the girders are multiplied by the distribution factors to calculate the design forces to include the effect of the load distribution laterally to the girders by the bridge deck. However, the use of these AASHTO distribution factors may not provide accurate estimate of the maximum forces for military vehicles, which usually have significantly different loading pattern than those of the civilian vehicles. Therefore, this study was conducted to develop new formulas for the lateral load distribution factors for military vehicles. The study considered six different types of military vehicles, three wheeled vehicles and the other three tracked vehicles. The bridge database used for developing AASHTO distribution factors formulas was also used in this study. The focus of this study was to develop the distribution factors formulas for three different types of bridges: steel girder bridges, pre-stressed concrete bridges, and concrete T-beam bridges. The bridges in each category were analyzed for the six types of military vehicles by the harmonic decomposition approach to calculate the distribution factor. This thesis provides a total of 52 new formulas for different types of vehicles, different types of bridges, bending moment and shear force values, interior and exterior girders, and for single and multiple lane loading cases. The distribution factors calculated with the formulas were compared with those calculated by direct analyses of the bridges to evaluate the accuracy of the proposed formulas. Comparisons were also made between the values calculated by the new formulas, post-LRFD formulas prescribed in 1996 AASHTO Standard Specification, and simple pre-LRFD formulas that were prescribed by AASHTO before 1994. / Master of Science

No description available.

The continuous permanent metal deck form system provides a quick and efficient method of constructing short-span, simply supported composite steel girder bridges. However, because shear studs can only be welded to the girder through the steel deck at rib locations, the number of shear stud locations is limited to the number of ribs in the shear span while the spacing of the shear studs is restricted to the rib spacing of the steel deck. This results in a condition where various provisions of the AASHTO LRFD Bridge Design Specifications (2007) cannot be satisfied, including shear stud fatigue spacing requirements and the fully composite section requirements. The purpose of this research was to investigate whether continuous permanent metal deck form construction method can be used for bridges given the code departures. Using this method, a full scale test specimen was constructed with one half of the specimen using one stud per rib and the other half using two studs per rib and then each half was tested separately. The steel deck used in the specimen was supplied by Wheeling Corrugating. Fatigue testing was conducted to determine the fatigue resistance of the specimen at both levels of interaction, with load ranges calculated using the AASHTO LRFD shear stud fatigue equation. This was followed by static tests to failure to determine the plastic moment capacity at both levels of interaction. Results of the testing were compared to existing design models and modifications specific to this construction method are made. Investigations into whether the profiled steel deck can act as full lateral bracing to the steel girder compression flange during deck placement were also made. Fatigue testing results showed that very little stiffness was lost over the course of testing at both levels of composite interaction. This leads to the conclusion that the AASHTO shear stud equation used for this design is conservative. Static testing results indicated that the measured values for the plastic moment capacity of the specimen were less than the calculated capacity. This leads to the conclusion that the individual shear stud strengths were overestimated using current design equations. Recommendations for modifications to the existing design equations are provided. / Master of Science

The aim of the master thesis was a design of the steel-concrete composite road bridge for a main road in Ostrava. The part of the design was a variant design of the bridge which has theoretical spans equal to 44 m + 55 m + 44 m. Total span of the bridge is then 143 m. Two variants of the bearing steel structure are compared in the preliminary structural design, in the first one a twin-girder is designed and in the second one a box-girder bridge is assessed. The width of the bridge is 14 m and a launching of the bridge without temporary supports is chosen as the assembly method. The design of the bridge structure was carried out according to the valid standard ČSN EN. The final thesis contains variant design, structural design report, where a bill of quantities is stated, engineering report and drawings.

Bridge redundancy can be described as the capacity that a bridge has to continue carrying loads after suffering the failure of one or more main structural components without undergoing significant deformations. In the current AASHTO LRFD Bridge Design Specification, two-girder bridges are classified as fracture critical, which implies that these bridges are not inherently redundant. Therefore, two-girder bridges require more frequent and detailed inspections than other types of bridges, resulting in greater costs for their operation. Despite the fracture-critical classification of two-girder bridges, several historical events involving the failure of main load-carrying members in two-girder bridges constructed of steel plate girders have demonstrated their ability to have significant reserve load carrying capacity. Relative to the steel plate girder bridges, steel box-girder bridges have higher torsional stiffness and more structural elements that might contribute to load redistribution in the event of a fracture of one or more bridge main members. These observations initiated questions on the inherent redundancy that twin box-girder bridges might possess. Given the high costs associated with the maintenance and the inspection of these bridges, there is interest in accurately characterizing the redundancy of bridge systems. In this study, twin steel box-girder bridges, which have become popular in recent years due to their aesthetics and high torsional resistance, were investigated to characterize and to define redundancy sources that could exist in this type of bridge. For this purpose, detailed finite element bridge models were developed with various modeling techniques to capture critical aspects of response of bridges suffering severe levels of damage. The finite element models included inelastic material behavior and nonlinear geometry, and they also accounted for the complex interaction of the shear studs with the concrete deck under progressing levels of damage. In conjunction with the computational analysis approach, three full-scale bridge fracture tests were carried out during this research project, and data collected from these tests were utilized to validate the results obtained from the finite element models. / text