Determining structural properties of a prestressed concrete bridge through the combination of static and dynamic load testing

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 φqp, φqs, and φload were proposed to be 0.65, 0.70, and 0.80, respectively.

In this paper, dynamic and static load test were carried out on a multi-span reinforced concrete simply supported hollow core slab bridge in Shenyang, Liaoning Province. Through the static load test, the quality and reliability of the project are evaluated, and the results show that under the action of 0.88 times of highway-classⅠload, the deflection and strain check coefficients of the control section of the tested condition are less than 1, which meets the specification requirements, and the measured relative residual deformation and relative residual strain are less than 20%, and the bridge structure is basically in the elastic working state. And combined with the finite element analysis model, the comparison between measured data and calculated data is carried out. Through the dynamic load test, the self-oscillation frequency and damping ratio of the superstructure were tested, and the results showed that the measured damping ratio was 0.690%, the first-order measured vibration pattern conformed to the variation rule of the vibration pattern of the simply supported girder bridge, and the measured self-oscillation frequency was 13.594 Hz, and the measured self-oscillation frequency (fundamental frequency) was greater than the calculated frequency, and the structural actual stiffness was greater than the theoretical stiffness, and the working condition was good. This study is of great significance for the assessment of bearing capacity and quality control of concrete hollow core slab bridge, and provides a useful reference for bridge design and operation.

Full-scale static loading is a widely accepted test method for authoritative assessment of deep foundations. Testing is typically performed once and the result is considered the definitive answer regarding the pile's load bearing capacity. However, there are technical and operational reasons that may cause misleading results. This paper presents a case where a large concrete pile was subjected to two full-scale static, and several dynamic loading tests. The pile was initially driven to a predetermined depth based on conventional geotechnical analyses, and its capacity was confirmed by dynamic testing. However, the static loading test indicated a pile capacity well below the anticipated value. Dynamic testing performed during restrike one day following the static test indicated a capacity close to that of the static load test. The pile was subsequently driven 4.4 m deeper until dynamic testing indicated it had achieved the required capacity. A second static loading test was performed that confirmed the required capacity. A review of the construction records revealed that in preparation for the static load test, the reaction steel H-piles were vibrated to below the test pile toe following the installation of the test pile. Analysis of the dynamic and static testing results confirmed that the installation of the reaction piles adversely affected the bearing layer resulting in reduction of pile capacity and the failed original static test. Utilization of dynamic pile testing and geotechnical analysis made it possible to uncover the flaw in the static loading test setup procedure and, thus, the unreliability of the original static load test result. This case study demonstrates that static load tests can sometimes be misleading, and supplemental dynamic pile testing is a valuable tool to establish reliability and ascertain fidelity of results.

Systematic studies of pile response during static and dynamic load tests are generally too expensive to conduct in the field, and at model scale may be limited by scaling effects and the ability to obtain accurate stress waves. This paper describes such a study, conducted at model scale in a geotechnical centrifuge, for piles driven into dense sand. Adverse scaling effects were minimized by the use of extremely fine sand (silica flour), and accurate stress waves were obtained using high-frequency data logging, together with a Hopkinson bar arrangement for the measurement of pile-head velocity. The overall aim of the study was to compare dynamic and static test data, for open- and closed-ended piles driven into dense sand, for a range of delivered hammer energies. Open- and close-ended model piles were driven into dense sand and statically load tested at different penetrations, without stopping the centrifuge. Stress-wave data were collected, during continuous driving and from single blows immediately prior to the commencement of static load testing. An assessment of the accuracy of the mobilized soil resistance estimated from dynamic testing, using different levels of analysis, has been made by direct comparison with the static load test data. Particular emphasis has been placed on the performance of the dynamic analyses in light of different driving conditions and delivered hammer energy. From measurements of the delivered hammer energy, the efficiency of the centrifuge pile driving system was also assessed.

Pilesr are both statically and dynami cally tried to acquire the limit and to check outline. The two sorts will give comes about that may differ in light of the technique utilized as a part of leading the test. It is thusly, important to think about the aftereffects of a static load test with dynamic load test. Numerous comparison studies are directed around the world, yet the vast majority of them are for displacement driven pile. In this way, the consequences of the test are looked at for substitution-exhausted piles. The piles are tested statically before dynamic test. The test results show that a not too bad comprehension was expert between both the tests with in addition to less 7mm at design load regarding settlement. Moderately, the settlement foreseen in powerful load test is littler diverged from static load test. Regarding absolute bearing limit, Davisson's technique gives the insignificant outrageous load regard diverged from various strategies. The Davisson's strategy is utilized to analyze the outcomes since it is more moderate. The examination shows that the piles are inside 15% in regard as far as possible traversed Davisson's strategy. Since the static test was coordinated before unique test, the limit got from dynamic test is higher because of the pile experienced flexible pressure amid static load test and furthermore because of soil setup.

In Belgium, there is little available data of dynamic versus static load tests, and even less so of piles installed in chalk. This paper tries to fill that gap by (1) presenting the results of static load tests instrumented with optical strain sensors performed by the Belgian Building Research Institute, (2) comparing those results to dynamic load tests performed using the Fondytest module by the Université Catholique de Louvain, and (3) reporting pile load test results of piles installed in chalk. The tests were performed on eight driven cast-in-situ piles in Belgium. Soil conditions consisted of layers of peaty clay and sand overlying a chalk bedrock, where the bases of two of the piles were cast, with the others being cast in the intermediate sand layer. This paper presents ground conditions of the test site, pile characteristics, static and dynamic load test operating procedures and interpretation details, and load-settlement results. Results and conclusions from both static and dynamic testing methods are presented.

Dynamic load testing is the most economical means of estimating deep foundation behavior under static loads. Unfortunately, this relatively quick and inexpensive test method has limitations: incomplete assessment of time-dependent soil resistance changes, incomplete resistance mobilization, failure criteria that differ from those for static tests, different failure modes in open-ended profiles, and sensitivity to high loading rates. Because of their economy, dynamic loading tests can be done on numerous piles at a site, whereas static loading tests must be limited to one or only a few piles. Modern codes such as American Association of State Highway and Transportation Officials specifications allow for increased resistance factors, equivalent to reduced factors of safety, when several dynamic tests are performed at a site. Even greater reductions of factors of safety are acceptable when the dynamic test is calibrated by comparison with static loading tests performed at the same site or at least under similar pile, soil, and hammer conditions. Exactly how to do such a calibration and how to combine the results of both types of tests is rarely discussed or specified. The calibration procedure is not a simple matter because it has to take into account the reasons for the differences between the two test types. This paper describes how to set up and perform effective test programs. Differences between the static and dynamic tests are explained and classified so that rational and specific recommendations for the test calibration process can be developed.

An instrumented pile load test was performed as part of the foundation design for the Caminada Bay Bridge project in south Louisiana. Both static and dynamic load tests were performed. The load-transfer curve of the test pile was obtained from strain measurements by using sister bar strain gauges at six locations along the pile shaft. The test pile resistance was determined by the Tomlinson method for cohesive soils and by the Nordlund method for cohesionless soils. The dynamic and the static load testing results indicated the test pile did not achieve the desired design resistance. The static analysis model was calibrated on the basis of observations of the pile load testing program. The design pile length was revised to benefit from the shallower scour depths for the revised pile design. The low resistance of the test pile resulted in the engineer's decision to use dynamic testing on the production piles to ensure adequate resistances. Taking advantage of the static load test of the instrumented test pile instead of simply using the smaller resistance factor from dynamic tests, the engineer combined the results of the two test methods and used a combination of resistance factors from both the static and dynamic load tests. This paper presents the evaluation of load test results and the rationale used for the selection of the resistance factor.

This paper examines shaft and base grouted concrete piles by conducting vertical static load tests (SLTs) and dynamic load tests. Three concrete piles with shaft and base grouting, with base grouting only, and without grouting techniques were selected, and compressive SLTs were conducted. Two piles with grouting were also assessed with dynamic load tests. Another two uplift SLTs were conducted to one shaft and base grouted pile and one pile without grouting. Traditional presentations were provided to check whether the bored piles reached the design requirement. Interpretations of test results were also provided to determine the ultimate pile capacity. Results from these 5 SLT programs indicated that double-tangent and DeBeer's methods are close to each other, and Chin's method overestimates the pile capacity. Comparison of the results from the SLTs and dynamic load tests shows that the results from Chin's method are close to dynamic results, and Mazurkiewicz's method overestimates for friction resistance. The results also demonstrate that base and shaft grouted pile and base grouted pile increase by 9.82% and 2.89% in compressive capacity, respectively, and compared to the uplift SLTs; there is a 15.7% increment in pile capacity after using base and shaft grouting technology.

Many advances have been made on driven piles bearing capacity tests, such as the static and dynamic load tests. However, the cost and the time necessary to prepare this kind of tests usually restricts its application to a small percentage of the piles. Consequently, simple and low-cost ways to estimate the bearing capacity of driven piles, for instance through the final set and the elastic rebound, can be used to control the majority of the piles, and then the results can be compared with more complex and accurate tests executed in fewer elements. The conventional manual way of measuring the elastic rebound is not considered a fully safe procedure, as the worker has to stay by the pile during the entire measuring procedure, which takes place during the last 10 blows. This paper describes the development of an in situ tool to measure the elastic rebound and the final set without any direct contact with the pile. Afterwards, these values can be used to evaluate the bearing capacity based on dynamic formulas proposed by many authors. The results from tests undertaken in a large number of piles, and in three different sites, comparing the conventional manual measurement and the apparatus agreed well, with a maximum discrepancy of about 13%. A direct comparison between the bearing capacity obtained via dynamic formulas, together with the new system measurements, and predictions obtained via dynamic tests was also presented, with very close results. Certainly more tests in different conditions with different pile materials are required to increase reliability. However, the presented solution seems to be a cheap promising way to measure the elastic rebound and the final set of driven piles, allowing the evaluation of the bearing capacity based on dynamic formulas. These data, associated with dynamic and static load tests results, are a powerful tool to improve quality control in pile drive operations.

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.

The basis of the long-term success of dental implants is the mechanical stability of the implant and the superstructure anchored in it. In order to investigate the mechanical behaviour of the conical connection in implant-abutment units, static and dynamic load tests were performed with different conical angles and various Grade 4-5 titanium implant materials. The assembled units were mounted in self-developed loading machine and in an Instron ElectroPuls E3000 fatigue machine. For static loading, the samples were loaded with a force from 0 N to 500 N in steps of 100 N. For dynamic loading, the samples were loaded for 30,000 cycles with a force of 250 ± 150 N. In case of static testing, the compression caused by the load was measured in both horizontal and vertical directions, while in the case of dynamic fatigue, only horizontal deformation was defined. In both cases, the drive-out (reverse) torque values of the fixing screws were determined after loading. No significant differences were found between the tested materials in the reverse torque after the static load, however, significant differences were shown with regards to the alterations in cone angle (p < 0.001). After dynamic loading, significant differences (p < 0.001) were also observed between the reverse torques of the fixing screw in different angles. The static and dynamic test results showed the same tendency: under the same load conditions, the conical angle value of the implant-abutment connection revealed significant differences in the loosening of the fixing screw. In summary, it is recommended to use higher conical angle connection to avoid larger deformations in lengths and diameters of the implant at the connection and essential torque reduction of the fixing screw. Our results may contribute to the understanding of the long-term success of dental implants.

Estimation of bearing capacity and settlement plays an essential role in designing pile foundations of buildings. This paper presents the results of pile static and dynamic loading tests taken place in the construction sites of Caspian Sea Port Prorva and Tengiz. The static loading tests (SLT) and static compression loading tests (SCLT) were carried out according to the Kazakhstan GOST and ASTM standards correspondingly. The dynamic loading tests (DLT) were performed by GOST, as well as by pile dynamic analyzer (PDA) in accordance with ASTM standards. According to the results of DLT of driven joint piles (with a cross-section of 40×40 cm, lengths of 25 m and 27 m) performed by PDA, the bearing capacity of the piles was 2143 kN. In the construction site of Prorva, the bearing capacities of driven joint piles according to the results of SCLT were2067 kN and 2042 kN. In the construction site of Tengiz, the bearing capacities of driven piles tested by SLT were 1000 kN and 1605kN. These investigations are important for the understanding of soil-structure interaction, especially of driven piles with a cross-section of 40x40 cm and lengths of 12 and 16m in construction site Tengiz.

A bored pile provides a large capacity obtained to toe and friction pile to support some loads such as axial, lateral, and tensile due to hydrostatic pressure or overturning moment. Static and dynamic load tests are often carried out to validate pile design before pile production in a project. This study aims to compare the ultimate capacity of the pile based on the result of static load test, dynamic load test, and pile design in granular soil of Batam, Indonesia, in which Chin-Kondner, Mazurkiewicz, Davisson, and Hansen 80% methods are utilized to obtain ultimate capacity (Qu) of static load test and dynamic test analysis apply Case Pile Wave Analysis Program (CAPWAP) method to gain ultimate capacity. The result analysis of the static load test of ultimate capacity using Chin-Kondner, Mazurkiewicz, Davisson, and Hansen 80% methods obtained results of 1379, 1300, 1375, and 1182 tons, respectively, with a Qu average of 1309 tons. A bearing capacity (RMX) of 1204 tons was obtained through a dynamic load test. Using the CAPWAP method based on the dynamic test, the ultimate bearing capacity (Ru) of 1248 tons was obtained. Analysis of pile design shows that the ultimate capacity of the bored pile in the granular soil of Batam, Indonesia, was 1157 tons. The Qu examination between field loading testing (1278.5 tons) and design pile foundation (1158 tons) was 9.4%.

An instrumented test pile was installed at the Bayou Zourie bridge reconstruction site as part of a Louisiana Department of Transportation and Development (LADOTD) research initiative to study the setup phenomenon of piles driven in Louisiana soils. Pile instrumentation included pressure cells to measure the total pressure at the pile face, piezometers to monitor the excess pore water pressure at the pile face, and “sister bar” strain gauges to measure the strain distribution along the pile. Additional instrumentation consisted of multilevel piezometers installed within soils at different locations/depths from the pile and accelerometers attached to the piles during dynamic load testing. A total of two static load tests and four dynamic load tests were conducted on the test pile. During the static load tests, the strains within the pile were measured by the strain gauges, which were used to calculate the distribution of load transfer along the pile. Both static and dynamic load tests demonstrated the increase in pile resistance with time (setup). Results of dynamic load tests confirmed that pile setup occurs at a logarithmic rate after the end of driving (EOD) and is mainly attributed to the increase in side resistance. Good correlation was observed in this study between the pile setup and the percentage of dissipated excess pore water pressure with time. The measured excess pore water pressure suggested that the surrounding soil, along the pile (within distance 2B), is significantly influenced during pile driving. Results indicated that the changes in side resistance are directly related to the changes in the horizontal effective stress acting on the pile face.