A Comparison Study for Static and Statnamic Load Tests on Two Instrumented Piles in Southeast Asia

The Port Mann Bridge on Highway 1 in Metro Vancouver links the cities of Surrey and Coquitlam in British Columbia, Canada. A new 10-lane 2.02 km long cable-stayed bridge is being constructed over the Fraser River to replace the existing 5-lane bridge. Twelve of the twenty-five bridge piers will be supported on driven steel pipe piles. As part of the foundation design approach, a full-scale instrumented static pile load test was performed along with dynamic pile testing. The test and reaction piles consist of 75 m long, 1,830 mm diameter by 25 mm thick, open-ended steel pipe piles driven into glacially overridden soil using an APE D-180-42 diesel hammer. A custom-built static load frame and hydraulic jacking system provided incremental compressive loads up to 53 MN on the test pile. Following the compression test, an uplift test to 29 MN was performed. The pile was restruck with a Menck MHU 500T hydraulic hammer 9 days after the uplift test. Evaluation of the pile resistance distribution included impacts of residual load and pile plugging. Pile performance during the static load test indicated that approximately 36 MN was carried in side resistance and approximately 17 MN was provided in base resistance. The static pile load test and dynamic testing of selected production piles enabled the use of increased resistance factors for final design, thereby reducing the number of piles to 255, a reduction of approximately 30 percent.

This paper employs a simplified analytical method to investigate the influence of reaction piles on the load–displacement behaviour of a test pile in static load testing. A parametric study is conducted to examine the effects of factors such as pile spacing ratio, pile slenderness ratio, and pile soil stiffness ratio. Several soil profiles are considered in the study. The parametric study also includes the cases of static load testing in the lateral direction. The correction factors for the initial pile head stiffness obtained from static pile load tests with the use of reaction piles are given in charts. Furthermore, analyses of centrifuge modelling of axially loaded piles are carried out using the simplified analytical method. Good agreements between the test results and the analysis results are demonstrated, and the applicability of the correction factors is verified.Key words: reaction piles, interaction, initial pile head stiffness, static vertical load testing, static lateral load testing, simplified analytical method.

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.

Static and dynamic tests were conducted at the time of driving on each of two instrumented piles driven into cohesive soils to embedded depths of 64 and 74 feet. The tests were repeated 11 days later in order to investigate the response of the reconsolidated soil. The purpose of this study was to investigate the time dependent force displacement response of cohesive soils induced by dynamic pile loads and to compare dynamic response with static response. All past attempts to achieve such comparisons were based either upon an assumed dynamic soil model and/or a simulated applied dynamic force estimated from the weight and speed of the driving hammer. In order to eliminate such assumptions in this study, the induced dynamic force was measured at five strategic locations along each instrumented pile. An accelerometer was used to record the motion at the head of the pile. This motion, together with the induced forces, were utilized in a multi degree spring-mass, system to directly compute the displacements of the masses representing various pile segments. The result of this analysis showed that when the applied loads were maximum, each pile experienced What may be described as rigid body motion. Consequently, a rigid pile model was utilized in a single-degree of freedom system to compute the dynamic soil resistance. Since both the dynamic soil resistance and the pile motions were known, a rigorous, or closed form solution of the equation of motion leads to a direct computation of the static component of soil resistance. This static component was found to approximate the static ultimate bearing capacity when the pile had experienced significant relative motion with respect to the soil. Introduction The bearing capacity of piles supporting Offshore structures is often determined by the so called static method. It is noteworthy that this method relies on correlations between soil shear strength, as determined from laboratory or in situ tests, to skin friction along the pile shaft and to end bearing below the pile point. Such relations have been reported by Terzaghi and Peck (15). Skempton (13), Tomlinson (16), Peck (9). Woodard et al. (18). and by Coyle and Reese (2). All of these studies undoubtedly advanced the state of the art. but uncertainties still remain. The overriding cause for uncertainty in the static method is that pile driving changes the shear strength of the clay, and it is difficult to estimate the strength of the clay after driving. In contrast to land piles, it is difficult to verify the design of offshore piles by static load tests, due to prohibitive costs and to high design loads that are difficult to attain. An alternate approach to the static field load test would consist of utilizing the resistance of the pile during driving as a dynamic field test to compute the static ultimate bearing capacity. The dynamic test may be conducted at any time after driving, and may therefore include some of the effects of soil reconsolidation and setup. However, dynamic test methods are not problem free for several reasons. First, the forcing function induced between hammer and pile is difficult to evaluate theoretically. Second, the relation between static and dynamic resistance is usually empirically defined by use of a damping coefficient which is held constant throughout the duration of impact. Even though this is an accepted procedure in the analysis of 1ineari1y elastic solids, it may not be sufficient for ultimate bearing capacity determinations in clay, because the material properties are vastly different.

Statnamic load testing was performed on three 66 inch (1,676 mm) diameter, post tensioned, spun cast, concrete cylinder piles and one 30 inch (762 mm) square pre-stressed concrete pile as part of a construction phase load test program for the replacement of the US 90 over Rigolets Pass Bridge near Slidell, Louisiana. The test program also included dynamic testing on all piles and static load testing of the 30 inch (762 mm) pre-stressed concrete piling. Statnamic loads approaching 6,000 kips (27 MN) were utilized on the cylinder piles to fully mobilize side shear in these predominantly friction piles. The static load test and Statnamic load test results on the same 30 inch (762 mm) square pile showed excellent agreement in both load and displacement up to the point of the limiting applied static load. The signal match on this pile showed greater displacement at similar loads. The Statnamic tests of the cylinder piles showed ultimate static capacities of 2,966 kips (13.3 MN), 3,077 kips (13.7 MN) and 3,315 kips (14.7 MN). While the CAPWAP analysis of re-strikes on these piles showed ultimate static capacities of 1,245kips (5.5 MN), 2,030 kips (9.0 MN), and 2,116 kips (9.4 MN). These results suggest that the Statnamic test method was able to fully mobilize the pile side shear resistance, while the dynamic test results were subject to the available hammer energy which was not sufficient to fully mobilize the ultimate static capacities.

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.

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.

Static load tests were performed on the pile two hours after driving and after four, sixteen, and twenty-nine months of consolidation and setup. The process of consolidation was essentially completed about twelve months after driving, so that the load tests encompass the complete life of a friction pile in highly plastic clays. Upon completion of the static load tests, the pile was subjected to a number of load variations that included cyclic loading in tension above and below a constant bias until failure was indicated by progressive pullout to large displacements. The pile was then subjected to alternate loading to failure in tension and compression to observe the maximum degree of cyclic degradation. Additional variations included studies of the effect of variations in the loading rate and large-displacement loading in compression to evaluate the end-bearing resistance, At the end of the field test program, load, pressure, and displacement data were recorded during pullout of the pile, Data were recorded for over fifty inches of axial displacement as the pile was removed, No significant losses in capacity were observed during pullout, indicating that temporary overload conditions on tension piles may not result in catastrophic failure particularly if redundancy is provided. Introduction At the time the study was initiated. little information was available regarding the setup behavior of long piles in normally consolidated highly plastic clays, The available load test data covering long periods of setup were limited to clays of low plasticity (Refs 1,2,3,4,5). Analytical methods that included consideration of reconsolidation and setup were limited to the empirical methods proposed by Soderberg (Ref 6) and the newly developed and untested finite-element solutions proposed by Carter, et at (Ref 7), Experimental data regarding the behavior of piles under cyclic axial loading in similar soils were limited to laboratory tests on model piles in a remolded soil (Refs 8, 9, 10). Computer programs had been developed to model the hysteretic nature of pile-soil interaction under cyclic loading. including the effects of cyclic degradation (Refs 11, 12), However. the programs had not been calibrated against actual load test data from prototype-size piles, The test program was therefore centered around a fully instrumented pile driven to a deep penetration in a soil deposit having a geologic history similar to Conoco's Green Canyon site in the deepwater Gulf of Mexico (Ref 13), In addition to measuring the load distribution along the pile the instrumentation was designed to obtain all the experimental data necessary to develop or verify evolving effective stress design procedures (Refs l4, 15), The load tests covered the full range of consolidation history and included static and cyclic loading in tension and two-way loading to failure in both tension and compression to provide a baseline for comparison of the effects of degradation during the cyclic tension tests. Load Test Programs While the load tests on the large-diameter instrumented pile provided invaluable information regarding the behavior of a long. elastic pile. the available variations in loading histories were very limited, Furthermore, the data were limited to only one pile of one diameter at one site.

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.

A full-scale, double-wall, open-ended pipe pile with a diameter, B = 660 mm was densely instrumented with a combination of electrical-resistance and vibrating-wire strain gauges. The test pile was driven into a gravelly sand soil profile to a depth of 30·48 m and then statically and dynamically load tested. The double-wall instrumentation allows independent measurements of the outer shaft, inner shaft (plug) and annulus resistances during a static load test. The residual loads locked in the pile after driving were measured and considered in the correction of the resistance components. The load–settlement curve, load transfer curves and the profile of the unit limit shaft resistance were obtained from the static load test measurements. Two cone penetration test-based methods were used to estimate the resistance of the test pile, which was compared with that obtained from the static load test. Both methods provide good estimates for the unit shaft resistance in sandy layers with low gravel content (<20%), but significantly overestimate the unit shaft resistance mobilised in soil with high gravel content (>30%). The estimated base resistances by both methods match well that measured in the static load test.

High Strain Dynamic Pile Test (HSDT) is increasingly being used for pile load testing. HSDT offers a considerable savings of time, cost and requires very little space compared to the conventional static test. However, it is yet mandatory to compare HSDT tests with static load tests (SLT) to confirm the validity of HSDT as the results are generally site specific. This study presents comparison of static pile load test (SLT) vs HSDT and attempt is made to close the gap between theoretical and practical justification for replacing SLT with HSDT by identifying the problems while conducting and comparing both the tests. Also, a resourceful methodology is produced to conduct efficient comparison of SLT and HSDT which can be used at any site.

This paper deals with the prediction of shaft resistance of single driven pile based on Meyerhoff formulation and empirical method based on SPT test. The accuracy of these predictions was evaluated by comparing the results with static load test (SLT) and dynamic loading test analyzed by Pile Driving Analyzer (PDA) and Case Pile Wave Analysis Program (CAPWAP) programs. The data for this study was collected from University Riau Hospital Project in Pekanbaru. The result of static and dynamic pile load test shows that only a small capacity of end resistance was mobilized due to insufficient pile deformation.

Static load test (SLT) and the Hybridnamic rapid load test (RLT) were carried out on an open-ended steel pipe pile (SPP) driven in sandy ground. The Hybridnamic RLT is a kind of falling mass type rapid load test, facilitating quick and efficient execution of multiple blows on a pile. SLT was carried out 25 days after pile driving, and RLT was carried out 8 days after the SLT. Static load-displacement curves were estimated from the RLT using various interpretation methods such as the UnLoading Point Connection (ULPC) method, the ULPC invoking Case method (ULPC_CM), and new methods (calleda aß method and aß_CM method). Static load-displacement curves from the SLT and the RLT with the various interpretation methods were compared to discuss the applicability of the various interpretation methods.

A rapid plate-loading test has more advantageous points than a static loading test, because it is performed at a simple condition and in a short time. The only relationship between a working load and settlement is obtained from the test. However, the works are on the increase to estimate the bearing capacity and the rigidity of ground at the site from the rapid plate-loading test. This report presents the comparisons between the results of the static and rapid loading tests, which were performed at the nine sites, and more the rigidity and the ultimate bearing capacity of the ground at the test sites, which are estimated from the rapid loading tests.

This research compares theoretical methods with static pile load test results to identify the most effective approaches for determining pile capacity across various soil and pile types, while also proposing modifications to the Bangladesh National Building Code (BNBC) 2020 guidelines. The study involved broad data collection from pile load test reports and subsoil investigations across six projects, focusing precast and cast-in-situ piles. Theoretical analyses were performed using i) bearing capacity equations as per BNBC 2020 (α-method and β-method), ii) Standard Penetration Test (SPT)-based BNBC 2020 method, and iii) SPT-based other methods from literature including Meyerhof, and Shioi Fukui equations. Following ASTM D1143 guidelines, eight evaluation methods were used to interpret load-settlement data from static load test. Statistical analyses involving Mean Absolute Percentage Error (MAPE), Bias Factor (λ), and Coefficient of Variation (COV) were conducted to evaluate predictive accuracy. Findings indicate that for clay soil, the SPT-based equations of Shioi & Fukui for skin friction and Meyerhof for end bearing can be considered as suitable alternatives for future BNBC revisions, showing lower variation with actual capacity. For sandy, silty, and layered soil devoid of clay, the SPT-based equations from BNBC 2020 are deemed appropriate.