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This paper presents the results and interpretations of static and dynamic tests that were executed on a newly built cable-stayed steel-concrete composite bridge during the final proof testing. A brief description of the structure, the testing methodology, and the used instrumentation are presented. Then, the test results are widely discussed and interpreted in order to evaluate the bridge performance during the proof test and also to understand the usefulness of each performed test in a proof test framework. All the collected experimental data are also compared to the numerical ones that were obtained through a refined finite element model, in order to check the behavior of the structure. The outcomes of the present work can offer references for the proof testing and monitoring of cable-stayed bridges.

Bridges are critical components of transportation networks, and fire accidents can significantly impair their structural integrity, leading to safety risks and major economic losses. This study presents a comprehensive inspection, materials testing, repair, and field load testing program for a full-scale concrete box girder bridge (Delta Bridge, Alexandria, Egypt) following a fire exposure on two spans. A total of 28 concrete core samples were extracted and tested, revealing average compressive strengths of 48.50 MPa (slab), 53.90 MPa (web), and 45.88 MPa (columns), representing moderate reductions of approximately 8.5%, 7.9%, and 10.8%, respectively, relative to the original in situ concrete strength recorded during construction, and 29.2%, 43.7%, and 30.0% increases over the minimum acceptance limits specified by Egyptian code of practice (ECP 203). Tensile strength tests on reinforcement bars indicated an average yield strength reduction coefficient of 0.87, corresponding to an estimated peak exposure temperature of 600 °C, yet still satisfying Egyptian code requirements (≥500 MPa). Field static load tests using 40-ton tri-axle trucks demonstrated maximum midspan deflections of 6.7 mm in fire-exposed spans and full recovery (>94%) upon unloading, confirming that the residual stiffness and load-carrying capacity were within acceptable limits. Based on these results, a targeted repair program was executed, including concrete cover replacement with shotcrete; steel derusting; surface coating; and bearing replacement, followed by a verification load test that confirmed the effectiveness of the rehabilitation. This case study demonstrates a robust framework for post-fire condition assessment, residual capacity evaluation, and repair validation of concrete box girder bridges. The methodology and findings provide valuable guidance for engineers and transportation authorities in mitigating fire-induced risks and ensuring the safe reopening of critical bridge infrastructure.

Recently, there have been many theoretical and experimental studies on advanced composite materials (ACM) bridges in various fields over the world. Compared with a reinforced concrete or steel bridge, an ACM bridge has more advantages in strength, stiffness, transportation, and installation. Many demonstration projects have been carried out in the U.S, and Europe. They are also being developed and tested in South Korea. In South Korea the first of all ACM short-span bridge superstructures was installed on a public highway system in May 2002. Since these composite materials are new to bridge applications, reliable data is not available for their in-service performance. This paper describes in-service performance assessment of all ACM bridge superstructures. To investiga te its in-service performance, field load testing and visual inspections were conducted under an actual service environment. The p aper includes the presentation and discussion for ACM Bridge capacity rating based on the stress modification coefficients obtained from the test results. The test result indicates that the ACM bridge superstructure has no structural problems and is structurally performing well in-service as expected. The results may provide a baseline data for future field ACM bridge capacity rating assessments and also serve as part of a long-term performance of ACM bridge superstructure.

This paper presents the results from a pile load testing program for a bridge construction project in Louisiana. The testing includes two 54-in. open-ended spun cast concrete cylinder piles, one 30-in. open-ended steel pile and two (30- and 16-in.) square prestressed concrete (PSC) piles driven at two locations with very similar soil conditions. Both cone penetration tests (CPTs) and soil borings/laboratory testing were used to characterize the subsurface soil conditions. All the test piles were instrumented with vibrating wire strain gauges to measure the load distribution along the length of the test piles and measure the skin friction and end-bearing capacity, separately. Dynamic load tests were performed on all test piles at different times after pile installations to quantify the amount of setup with time. Static load tests were also performed on the PSC and open-ended steel piles. Due to expected large pile capacities, the statnamic test method was used on the two open-ended cylinder piles. The pile capacities of these piles were evaluated using various CPT methods (such as Schmertmann, De Ruiter and Beringen, LCPC, Lehane et al. methods). The result showed that all the methods can estimate the skin friction with good accuracy, but not the end-bearing capacity. The normalized cumulative blow counts during pile installation showed that the blow count was always higher for the PSC piles compared to the large-diameter open-ended cylinder pile, regardless of pile size and hammer size. Setup was observed for all the piles, which was mainly attributed to increase in skin frictions. The setup parameters “ A ” were back-calculated for all the test piles and the values were between 0.31 and 0.41.

Many countries worldwide face a common problem with the aging bridge infrastructure that is being demanded to carry increasing loads. With the cost and the difficulties associated with replacing and rehabilitating these bridges, it is necessary to make the most efficient use of the existing infrastructure. Proof load testing (PLT) proved to be a reliable non-destructive method to assess the bridge and reflect its actual behavior, especially the old bridges. The advancement on the Internet of Things (IoT) technology concerning sensors and data acquisition systems for sensing, collecting, and storing the data in conjunction with Finite Element Modeling has resulted in combining analytical models and field test results for better assessment of the bridge condition. It would be insightful to combine the field-testing data with Finite Element Modeling to optimize the outcomes from proof load tests. In this paper, the case of the I-39 Kishwaukee, a five-span twin post-tensioned segmental concrete box girder bridge, has been studied. Kishwaukee bridge was built in 1970. Several retrofits were carried out on the structure to solve the cracks and slippage at the shear key between the pier segment and the adjacent cantilever segment caused by non-hardened epoxy at the joint during the time of construction. In 2006, The Illinois Department of Transportation investigates the structural behavior of the bridge and determined that the crack growth along the webs is caused by principal tensile stresses higher than the code limits. Using the FEA, the model shows an estimated permanent strain of 85 µɛ caused by the dead load only at the shear key. This strain added to the strain caused by the HS20 truck live load led to a total strain of 180 µɛ higher than the strain corresponding to the modulus of rupture of the concrete (135 µɛ). A total estimated deflection of 3.84 in. at midspan of Span #3 caused by HS20 truck live load exceeded the AASHTO allowable limit for deflection (3.74 in). Since the bridge was deficient, IDOT decided to strengthen the structure using four–12 strands, 15 mm external post-tensioning tendons placed inside the box girders to reduce the shear forces acting across the webs. This paper illustrates a proof of four different trucks loading weights of 76 tons (167 k), 90 tons (200 k), 122 tons (268 k), and 136 tons (300 k) conducted on the bridge. Nine testing scenarios were successfully completed with a maximum of two testing trucks of approximately 136 tons (300 k). The data obtained from the field test (Measured strains near the pier, where shear and negative moment are critical, and at midspan, where the positive moment is crucial, and measured deflection profiles) were used to optimize a non-linear finite element model for the bridge. This paper provides a comprehensive guide on how to conduct load rating assessments based on the AASHTO MBE method for PLT. It outlines a step-by-step procedure for conducting field operations, implementing instrumentation, and interpreting test results. The data obtained from the field test are used to develop a Finite Element Model showing the impact of the recently introduced external post-tensioning tendons on the structural performance of the bridge. In conjunction with the FEA, this research demonstrated that the rehabilitation of Kishwaukee I-39 bridge using the post-tensioning system reduced the deflection by 88.72%, and minimized the principal tensile strain of the shear key by 80µɛ. Based on these findings, this paper provided a significant allowance for accommodating future traffic load increases on the Kishwaukee I-39 River bridge.

In this work, the phase-field approach to fracture is extended to model fatigue failure in high- and low-cycle regime. The fracture energy degradation due to the repeated externally applied loads is introduced as a function of a local energy accumulation variable, which takes the structural loading history into account. To this end, a novel definition of the energy accumulation variable is proposed, allowing the fracture analysis at monotonic loading without the interference of the fatigue extension, thus making the framework generalised. Moreover, this definition includes the mean load influence of implicitly. The elastoplastic material model with the combined nonlinear isotropic and nonlinear kinematic hardening is introduced to account for cyclic plasticity. The ability of the proposed phenomenological approach to naturally recover main features of fatigue, including Paris law and Wöhler curve under different load ratios is presented through numerical examples and compared with experimental data from the author’s previous work. Physical interpretation of additional fatigue material parameter is explored through the parametric study.

This paper presents the results of a recent field test carried out before the opening phases of the Szapáry motorway bridge across the Tisza River in central Hungary. The evaluation test was based on static and dynamic load tests that provided information on deflection, stresses, and dynamic mode shapes along the bridge. The structure has two large continuous independent steel box girders that cover spans across the floodplain and river. Various configurations of truck loading applied up to 6400 kN of loading on the deck. During the static tests, string potentiometers recorded deflections at mid-span. Additionally, strain gauges enabled strain/stress measurements at the mid-point of the longest span and directly above one support. Dynamic loadings showed variation in deflection response due to vehicle speed, and ambient vibration testing led to determining vibration modes and frequencies. A three-dimensional finite-element model produced similar deflections, stresses, and modal behavior. Measured and modeled deflections and stresses indicated that the bridge performed within design margins. The testing and analysis results will be part of a future program assessing conditioned-based maintenance.

In this paper, joint precast piles with a cross-section of 400 × 400 mm and a pin-joined connection were considered, and their interaction with the soil of Western Kazakhstan has been analyzed. The following methods were used: assessment of the bearing capacity using the static compression load test (SCLT by ASTM) method, interpretation of the field test data, and the dynamic loading test (DLT) method for driving precast concrete joint piles, including Pile Driving Analyzer (PDA by ASTM) and Control and Provisioning of Wireless Access Points (CAPWAP) methods. According to the results, the composite piles tested by the PDA (by ASTM) method differ by 15 percent compared to the static load method, while the difference between the dynamic DLT (by ASTM) method and the static load (by ASTM) method was only 7 percent. So, according to the results, the alternative dynamic method DLT (by ASTM) is very effective and more accurate compared to other existing methods.

Unlike conventional grouted micropiles, screw micropiles have been recently introduced to the foundation industry. Full-scale field tests of screw micropiles were carried out at a cohesive soil site. The screw micropiles have a diameter varying from 76 to 114 mm and a length varying from 1.6 to 3 m, and spiral threads welded on the lower half of the steel tubular shaft. Site investigation from cone penetration tests (CPT) and laboratory testing implies that the soil was medium to stiff, low plasticity clay. Six axial monotonic and three axial cyclic load tests were performed on three micropiles. One micropile was instrumented with strain gauges to investigate the shaft load distribution during loading. The axial cyclic loading was intended to simulate cyclic inertia load during vertical ground motions. Results showed that the micropiles behave as frictional piles during monotonic tests; the unit shaft resistance and adhesion coefficient were calculated and compared with results in the literature. The end installation torque was estimated using CPT shaft resistance and was shown to agree reasonably with the measured torque. Under axial cyclic loading, the micropiles underwent small cumulative displacements and the magnitude of the displacement decreased with increasing pile length and diameter. Cyclic loading redistributed the load transfer along different segments of the micropile. Negative skin resistance was observed along the smooth pile shaft when the pile underwent decreasing axial loading.

This paper presents a group of field tests to investigate the shaft capacity of pre-bored grouted planted (PGP) pile embedded in deep soft soil. Totally three test PGP piles were designed for the static load tests. The fiber optic sensors were equipped along the PHC pile shaft of two test piles to investigate the reliability and accuracy of fiber optic sensors on measuring the axial force of PGP pile. The diameter of cemented soil column of test PGP pile was 560 mm, and the diameter of core PHC pipe pile was 400 mm. The thickness of cemented soil layer around the PHC pipe pile reached 80 mm. The test results showed that: the base capacity of three test piles were all not fully mobilized when loaded to the designed ultimate capacity 3000 kN, and the base capacity of test pile TP1 and TP2 were 14.4% and 14.8%, respectively of the applied pile head load when loaded to 3000 kN. The skin friction of cemented soil–soil interface was fully mobilized when the pile–soil relative displacement reached 10 mm, 1.8% D (D is pile diameter). The measured ultimate skin friction of test pile TP1 and TP2 in different soil layers were 1.21–1.88 times of the recommended ultimate skin friction of bored pile, which can be used for the design of PGP pile in following engineering projects. The increase of cemented soil layer thickness (increase of pile diameter) could increase the entire shaft capacity of PGP pile, on the condition that the core PHC pile and cemented soil layer act as a unit in the load transfer process.