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To evaluate the true load-bearing capacity and engineering reliability of a large span through a simply supported steel box arch bridge, a load test was conducted on the bridge. The example used in this test is the Jingchu Avenue Bridge located in Jingmen City, Hubei Province. Specifically, the static load test delineated six operational conditions, measuring parameters encompassing strain, hanger cable force, deflection, and potential cracks. The dynamic load test gauged the bridge's dynamic response and various indicators, including pulse tests, vehicle tests, jump tests, and barrier-free vehicle tests. The findings indicated that the maximum measured strain values during the static load test surpassed the calculated values; nonetheless, the verification factors and relative residual strains adhered to the code requirements, and no cracks were detected. The dynamic load test unveiled that the measured frequency values exceeded the theoretical ones, the damping ratios were within the normal range, and the measured impact coefficients were lower than the values stipulated in the code, all of which were in conformance with the code requirements. The data obtained from this experiment can be utilized to refine the long-term maintenance plan for the bridge, especially as it holds considerable value for structural health monitoring and aging assessment. [ABSTRACT FROM AUTHOR]

Technological procedures related to the possession of tracks are often under heavy time constraints. Therefore, the attempts to apply dynamic load tests in the process of diagnostics of implemented construction works on modernised sections of railway infrastructure are increasingly frequent. When modernising constructing traffic constructions – even if dealing with technological works not related to the possession of tracks – it is often necessary to ensure a rapid progression of individual work activities or to carry out diagnostics tests in the sections with limited access to mechanisation. This test is reasonably suitable to detect critical areas not compliant with deformation standards. The combination of dynamic load tests with the static load test in these areas could, therefore, prove to save time as well as financial expenses spent on construction works inspection diagnostics. Based on the above-mentioned reasons, the presented article is focused on the analysis of set values of the dynamic modulus of deformation, obtained through light dynamic load test LDD 100, and the static modulus of deformation obtained by employing the test procedure set out in the methodology regarding the sub-ballast layers diagnostics used for German railways (DIN 18 134) and the methodology used for the Railways of the Slovak Republic (regulation ŽSR TS4). [ABSTRACT FROM AUTHOR]

This paper presents an analysis of long, large-diameter bored piles' behavior under static and dynamic load tests for a megaproject located in El Alamein, on the northern shoreline of Egypt. Site investigations depict an abundance of limestone fragments and weak argillaceous limestone interlaid with gravelly, silty sands and silty, gravelly clay layers. These layers are classified as intermediate geomaterials, IGMs, and soil layers. The project consists of high-rise buildings founded on long bored piles of 1200 mm and 800 mm in diameter. Forty-four (44) static and dynamic compression load tests were performed in this study. During the pile testing, it was recognized that the pile load–settlement behavior is very conservative. Settlement did not exceed 1.6% of the pile diameter at twice the design load. This indicates that the available design manual does not provide reasonable parameters for IGM layers. The study was performed to investigate the efficiency of different approaches for determining the design load of bored piles in IGMs. These approaches are statistical, predictions from static pile load tests, numerical, and dynamic wave analysis via a case pile wave analysis program, CAPWAP, a method that calculates friction stresses along the pile shaft. The predicted ultimate capacities range from 5.5 to 10.0 times the pile design capacity. Settlement analysis indicates that the large-diameter pile behaves as a friction pile. The dynamic pile load test results were calibrated relative to the static pile load test. The dynamic load test could be used to validate the pile capacity. Settlement from the dynamic load test has been shown to be about 25% higher than that from the static load test. This can be attributed to the possible development of high pore water pressure in cohesive IGMs. The case study analysis and the parametric study indicate that AASHTO LRFD is conservative in estimating skin friction, tip, and load test resistance factors in IGMs. A new load–settlement response equation for 600 mm to 2000 mm diameter piles and new recommendations for resistance factors φ qp, φ qs, and φ load were proposed to be 0.65, 0.70, and 0.80, respectively. [ABSTRACT FROM AUTHOR]

To evaluate the true load-bearing capacity and engineering reliability of a large span through a simply supported steel box arch bridge, a load test was conducted on the bridge. The example used in this test is the Jingchu Avenue Bridge located in Jingmen City, Hubei Province. Specifically, the static load test delineated six operational conditions, measuring parameters encompassing strain, hanger cable force, deflection, and potential cracks. The dynamic load test gauged the bridge’s dynamic response and various indicators, including pulse tests, vehicle tests, jump tests, and barrier-free vehicle tests. The findings indicated that the maximum measured strain values during the static load test surpassed the calculated values; nonetheless, the verification factors and relative residual strains adhered to the code requirements, and no cracks were detected. The dynamic load test unveiled that the measured frequency values exceeded the theoretical ones, the damping ratios were within the normal range, and the measured impact coefficients were lower than the values stipulated in the code, all of which were in conformance with the code requirements. The data obtained from this experiment can be utilized to refine the long-term maintenance plan for the bridge, especially as it holds considerable value for structural health monitoring and aging assessment.

The large-span prestressed concrete beam bridge has been widely used due to its advantages of high structural stiffness, smooth and comfortable traffic, good seismic performance, and mature construction technology. However, after a long period of service, such bridges may develop cracks in their structure due to the long-term effects of natural environment and overloading, which can affect their safe carrying capacity. This problem is particularly prominent for long-span bridges over the sea. Therefore, in order to accurately assess the actual working condition and carrying capacity of an in- service long-span prestressed concrete beam bridge over the sea, on-site static and dynamic load tests on a bridge that has been in service for 15 years are conducted. The characteristics such as vibration mode were analyzed using finite element analysis. The research results indicate that the structural performance of the bridge remains good, but the actual carrying capacity has decreased due to structural damage and crack formation caused by the environmental conditions in the marine area and long-term service. The findings of this study can provide reference for the maintenance and strengthening of similar in-service bridges. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the construction process of a cable-stayed bridge with corrugated steel webs was monitored. Moreover, the end performance of the bridge was verified by load test. Owing to the consideration of the bridge structure safety, it is necessary to monitor the main girder deflection, stress, construction error and safety state during construction. Furthermore, to verify whether the bridge can meet the design requirements, the static and dynamic load tests are carried out after the completion of the bridge. The results of construction monitoring show that the stress state of the structure during construction is basically consistent with the theoretical calculation and design requirements, and both meet the design and specification requirements. The final measured stress state of the structure is within the allowable range of the cable-stayed bridge, and the stress state of the structure is normal and meets the specification requirements. The results of load tests show that the measured deflection values of the mid-span section of the main girder are less than the theoretical calculation values. The maximum deflection of the girder is −20.90 mm, which is less than −22.00 mm of the theoretical value, indicating that the girder has sufficient structural stiffness. The maximum impact coefficient under dynamic load test is 1.08, which is greater than 1.05 of theoretical value, indicating that the impact effect of heavy-duty truck on this type of bridge is larger. This study can provide important reference value for construction and maintenance of similar corrugated steel web cable-stayed bridges. [ABSTRACT FROM AUTHOR]

Xinhe Bridge is a newly built large-span half-through steel box basket-handle arch bridge with a main span of 196 m. In order to evaluate the mechanical performance of the bridge under the service load and verify whether it reaches the design expectations, load tests have been carried out on the bridge. In the static load test, 11 control sections were selected for measuring several mechanics parameters, including strain, suspender cable force, deflection, and horizontal displacement of the abutment. In the dynamic load test, the natural frequency and the dynamic response under the vibration excitation, such as a vehicle running load, bumping load, and braking load, were tested. The results show as follows. The structural verification coefficient and relative residual meet the requirements of the code. The cable force of the suspender and the horizontal displacement of the abutment have a large surplus. The measured natural frequency is higher than the calculated frequency. The measured damping ratio is less than 5%. The measured impact amplification coefficient is 1. 176 ~ 1. 371. Each performance of the test achieves the design expectation. [ABSTRACT FROM AUTHOR]

Piles driven in cohesive soils usually experience a large increase in capacity over time, known as setup or freeze. This paper presents the field results of two test piles that were driven in two different locations of Louisiana to evaluate the pile setup behavior. Laboratory and in situ soil testings (cone penetration test, CPT) were conducted to characterize the subsurface soil properties. Several dynamic load tests (DLTs) and one static load test (SLT) were conducted on each test pile at different times after end of driving (EOD) to quantify the magnitude and rate of setup. The test pile in one site was instrumented with vibrating wire strain gages to calculate the load-distribution along the length of the pile during the static load test. With the aid of Case Pile Wave Analysis Program (CAPWAP®) analyses and load distribution plots from strain gages, skin friction and end-bearing capacities were measured separately. The load test results showed that the setup was mainly attributed to increase in skin friction with time and end-bearing capacity remained almost constant. The load test results also showed that setup behavior was more significant in soft cohesive soil. The pile capacity of one test pile was also evaluated using different CPT methods (such as Schmertmann, De Ruiter and Beringen, LCPC). The result showed that all the methods can estimate the pile capacity with good accuracy. [ABSTRACT FROM AUTHOR]

Considering a great number of newly built bridges at home and abroad, this paper aims to study how to effectively check the technical status such as construction quality, and bearing capacity etc. of the prestressed concrete simply supported bridges using the dynamic and static load tests. First, the finite element calculation was conducted to simulate various construction conditions of the bridge and calculate the actual bridge's bearing capacity. Then, taking Yanxi Bridge as an example, the authors carried out dynamic and static load tests and finite element theoretical calculations to analyze the deflection and strain of the bridge structure during the static load test, as well as the frequency, damping and patterns obtained from the dynamic load test. As a result, the bridge quality was reasonably evaluated. The analysis results show that the bearing capacity and structural rigidity of the bridge meet the design requirements. The research findings shall provide references for the completion acceptance of other bridges. [ABSTRACT FROM AUTHOR]

In order to evaluate the actual bearing capacity and condition of a cable-stayed bridge in detail, the static and dynamic load tests of the bridge are carried out to test and analyze the static parameters such as the strain of the main girder control section, the local strain of the bridge deck, the deflection of the main girder, the vertical deviation of the tower top and the strain of the tower root, and the dynamic response of the bridge, such as impact coefficient, natural frequency and mode of vibration. The analysis results show that the measured data of each measuring point are generally in good agreement with the calculation. The check coefficient of some measuring points is greater than 1. 0, and the impact coefficient is greater than the calculated value in the dynamic load test. The damping ratio is 0. 338%-1. 115%, which indicates that the bearing capacity of the structure is low. The research conclusion has certain significance for the analysis of the bearing capacity of similar bridges. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a new approach of estimating pile setup starts from the end-of-drive (EOD) resistance by the use of a power function model followed by a log-linear function. Often pile setup is estimated using the Skov and Denver(in: Proceedings of the 3rd international conference on the application of stress-wave theory to piles, Canada, 1988) model, which requires knowing the pile resistance at a reference time (to). This requires additional effort for testing the pile at the reference time (to). This effort may cause delay in the foundation construction and thus increasing the cost of construction. Pile load testing program was conducted on seven 914 (36 in.) square close-ended prestressed concrete (PSC) test piles at the Caminada Bay bridge project in coastal Louisiana to develop a methodology to estimate pile setup effectively starting from EOD resistance. Several dynamic load tests (DLTs) were performed on each test pile, with waiting periods of 60 min to 55 days after installation, to measure the magnitude and rate of setup. Static load tests (SLTs) were also performed at the end of the load testing program to validate the results of dynamic load tests. The load testing results showed that the total resistance increased up to 12 times of the EOD resistances after 28 days from EOD. The Skov and Denver (1988) setup parameter “A” was calculated for each test pile using different initial reference times (to). The results showed that the setup parameter “A” was highly variable and uncertain for to less than 1 day. This paper proposes a new power pile setup model that can be used to estimate pile setup immediately after EOD to the initial reference time, to, which is usually 1 day for a log-linear model. The proposed model was validated using results from published case studies for various geological conditions, which shows that the results of the model effectively match the setup test results within a small tolerance. [ABSTRACT FROM AUTHOR]

The typical properties of Lightweight Concrete Pile (LCP) are low density, low strength and high porosity. Such inherent properties made use of LCP for deep foundation are still rare. In spite of Normal Concrete Pile (NCP) has been widely used in civil engineering industry, the use of LCP such as palm oil clinker concrete pile (p-LCP) and foamed concrete pile (f-LCP) for floating foundation must be verified. The purpose of this study was to perform the static and dynamic load tests for assessing the performance of p-LCP and f-LCP and that of NCP as reference. The physical characteristics of either p-LCP or f-LCP have higher average values of compressive stress and driving resistance comparing with NCP. Features of good performance for p-LCP and f-LCP can be used for deep foundation of particular structures in soft soil and were verified to contribute to material and structural perspectives for the future of geotechnical engineering. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The uplift load test is the most widely used technique for assessment of the performance of micropiles. Although this static load test is easy to perform and interpret, it is expensive, slow to implement, and cannot be used systematically because it destroys the micropile. A new methodology based on a simple low-strain dynamic load test (LSDT) is proposed to develop a systematic and inexpensive method for assessment of performance of a large number of micropiles. The advantage of this methodology is that it is easy to carry out, requires lowimpact energy compared with a classical dynamic load test, and allows immediate interpretation. After describing the proposed methodology, the calibration, and the subsequent validation of the test method, results from full-scale micropiles at an experimental site and three real sites are presented. The results show that the methodology proposed allows confirming micropile performance under service loads in real time without disturbing the micropile. [ABSTRACT FROM AUTHOR]

Three selected bored piles executed at Basrah area were tested both bystatic and dynamic pile test procedures in order to correlate their results when evaluating the piles capacities. The correlation showed that the results are close to each other in terms of load- settlement relations, but on the other hand, end bearing capacity and skin friction values obtained by the dynamics tests are far from the real behavior of piles. The reason may be due to lack of experience ofcrew that supervises the dynamic tests. They have to practice more dynamic tests and should build accumulated knowledge about the dynamic method of testing piles. The time is still early for the dynamic tests to replace the classical static test when evaluating piles capacities.