scholarly journals Field Tests on Bearing Characteristics of Large-Diameter Combined Tip-and-Side Post Grouted Drilled Shafts

2021 ◽  
Vol 11 (24) ◽  
pp. 11883
Author(s):  
Zhitong Zhang ◽  
Weiming Gong ◽  
Guoliang Dai ◽  
Xiaolin Cao ◽  
Yu Zhu ◽  
...  
Keyword(s):  
Large Diameter ◽  
Standard Penetration Test ◽  
Drilled Shafts ◽  
Load Test ◽  
Cohesionless Soil ◽  
Cement Slurry ◽  
Test Procedures ◽  
Loading Test ◽  
Static Test ◽  
Tip Resistance

This paper presents a field study on the axial behavior of four large-diameter drilled shafts embedded in coarse sand. The grouting and loading test procedures were reported. The bearing capacity of shafts (TS1 and TS2) and grouted drilled shafts (TS3 and TS4) were herein determined by the bi-directional static test and top-down load test, respectively. The enhancement mechanism of bearing characteristics of the grouted shafts was discussed in detail. The test results indicate that the bearing characteristics and load transfer mechanisms of the test shafts were significantly affected by the quantity of pressurized cement slurry and the mechanical properties of the soil surrounding the shafts. Furthermore, the tip resistance of shaft can be mobilized more rapidly and fully after grouting, the side and tip resistance are mobilized in a more synchronized and coordinated manner due to the pre-mobilization of the grouted cement. Additionally, the standard penetration test (SPT) prediction model was introduced to calculate and predict the SPT blow counts of soil after grouting. The results show that the post grouting has a more obvious improvement on the strength of cohesionless soil.

Pull-out bond strength and flexural load test of concrete beam with ethylene-vinyl acetate–modified cement slurry-coated rebar

2018 ◽  
Vol 21 (14) ◽  
pp. 2130-2142 ◽  
Author(s):  
Youngkug Jo ◽  
Jeongyun Do
Keyword(s):  
Bond Strength ◽  
Vinyl Acetate ◽  
Concrete Beam ◽  
Ethylene Vinyl Acetate ◽  
Load Test ◽  
Cement Slurry ◽  
Loading Test ◽  
Pull Out ◽  
Flexural Loading ◽  
Early Strength

A study has been conducted on a bond strength test of ethylene-vinyl acetate–modified ultra-high early strength cement slurry–coated rebar embedded in concrete and did a flexural loading test with the aim to verifying the feasibility of early strength cement slurry–coated rebar as a replacement for epoxy-coated rebar. Pull-out bond properties of the early strength cement slurry–coated rebar embedded in concrete with a 28-day compressive strength of 27 MPa depending on the coating thicknesses, curing ages, and polymer–cement ratios were experimentally investigated and mutually compared with two respective references consisting of a plain steel rebar and an epoxy-coated one. The effects of the uncoated, early strength cement slurry–coated, or epoxy-coated rebar embedded in a concrete beam with dimensions of 250, 350, and 3000 mm for the depth, height, and length, respectively, on the flexural loading capacity were investigated. From the results of this study, it was concluded that the early strength cement slurry–coated rebar with a coating thickness of 100 µm, and a curing time of 7 days could be competitive enough to replace epoxy-coated rebar based on the bond strength and flexural loading test results.

Nonlinear Analysis of Settlement for Cohesionless Soil Foundations Based on In Situ Tests

2012 ◽  
Vol 204-208 ◽  
pp. 107-114
Author(s):  
Ren Ping Li ◽  
Jie Liu
Keyword(s):  
Limit State ◽  
Standard Penetration Test ◽  
Summation Method ◽  
Tangent Modulus ◽  
Cohesionless Soil ◽  
Soil Parameters ◽  
Ultimate Limit State ◽  
In Situ Tests ◽  
Loading Test

A new technique is proposed to calculate nonlinear settlement for foundation by using the data of plate loading test (PLT) and standard penetration test (SPT) or other in-situ tests. Firstly, hyperbolic curve is fitted out from the data of PLT and the tangent modulus equation of soil is established, then correctional tangent modulus (CTM) equation is established by feedback adjusting according to the fitting curve of PLT; Secondly, the CTM equations of different stratified soil at different depth are determined by soil parameters of SPT or other in-situ tests according to linear correlation; Finally, the nonlinear settlement of foundation is calculated by the layerwise summation method. An engineering application of settlement prediction for the largest oil tank in China indicated that this technique is able to calculate the entire nonlinear settlement from initiation to ultimate limit state and obtain accurate results, and it is suitable for cohesionless soil with high permeability.

scholarly journals Behavior of a Large Diameter Bored Pile in Drained and Undrained Conditions: Comparative Analysis

Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 261
Author(s):  
Mohamed Ezzat Al-Atroush ◽  
Ashraf Hefny ◽  
Yasser Zaghloul ◽  
Tamer Sorour
Keyword(s):  
Numerical Models ◽  
Large Diameter ◽  
Field Measurements ◽  
Load Test ◽  
Design Parameters ◽  
Test Problems ◽  
Loading Test ◽  
Stiff Clay ◽  
Undrained Conditions ◽  
Drained And Undrained Conditions

Despite the difficulties in obtaining the ultimate capacity of the large diameter bored piles (LDBP) using the in situ loading test, this method is the most recommended by several codes and design standards. However, several settlement-based approaches, alongside the conventional capacity-based design approach for LDBP, are proposed in the event of the impossibility of performing a pile-loading test during the design phase. With that in mind, natural clays usually involve some degree of over consolidation; there is considerable debate among the various approaches on how to represent the behavior of the overconsolidated (OC)stiff clay and its design parameters, whether drained or undrained, in the pile-load test problems. In this paper, field measurements of axial loaded to failure LDBP load test installed in OC stiff clay (Alzey Bridge Case Study, Germany) have been used to assess the quality of two numerical models established to simulate the pile behavior in both drained and undrained conditions. After calibration, the load transfer mechanism of the LDBP in both drained and undrained conditions has been explored. Results of the numerical analyses showed the main differences between the soil pile interaction in both drained and undrained conditions. Also, field measurements have been used to assess the ultimate pile capacity estimated using different methods.

scholarly journals Full-Scale Well Instrumented Large Diameter Bored Pile Load Test in Multi Layered Soil: A Case Study of Damietta Port New Grain Silos Project

2018 ◽  
Vol 8 (01) ◽  
Author(s):  
M. Eid ◽  
A. Hefny ◽  
T. Sorour ◽  
Y. Zagh
Keyword(s):  
Load Distribution ◽  
Large Diameter ◽  
Soil Layer ◽  
Full Scale ◽  
Layered Soil ◽  
Load Test ◽  
Test Field ◽  
Loading Test ◽  
Bored Pile ◽  
Pile Load Test

A Large diameter bored pile with diameter of 1.00 m and length of 34.00 m has been implemented in multi layered soil. The pile was tested under three axially loading and unloading cycles, in order to determine the load settlement curve and assess the ultimate pile capacity. Extensive investigation was carried out to obtain reliable soil properties at the examined pile location, through in situ and laboratory soil tests. Twelve strain gauges were fixed on pile steel reinforcement bars at top of each soil layer level. Moreover, four dial gauges were set up at pile head. Also, three telltales were extended to three different levels inside the pile. The pile load test field measurements are presented in the form of load settlement and load distribution curves for different loading steps. In addition, the pile ultimate capacity is calculated using different codes criterions and compared with the loading test results. Large diameter bored pile, Settlement, Pile load distribution, Pile installation, Instrumentation, Full scale pile load test, Pile behavior.

Vertical Loading Test on the Bearing Capacity of Large-Diameter Filling-Piles in the Mudstone and Sandstone Foundation

2013 ◽  
Vol 639-640 ◽  
pp. 587-592 ◽  
Author(s):  
Hui Yang ◽  
Xue Liang Jiang ◽  
Jun Fu
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Large Diameter ◽  
Load Test ◽  
Sediment Thickness ◽  
Loading Test ◽  
Friction Resistance ◽  
Vertical Loading ◽  
Pile Diameter ◽  
Side Friction

Based on the vertical loading test results of large-diameter filling pile near an electric factory in the sandstone and mudstone foundation, the load transfer mechanism and vertical loading bearing behavior of the pile were discussed. The analysis shows that the pile mainly behaves as friction piles and the vertical bearing capacity is mainly supplied by side friction resistance. The pile side friction is related to the section displacement of pile, the pile load and the soil characteristic. The pile end resistence is related to pile end settlement, pile diameter, rock-socketed length,rock elasticity modulus of pile end, sediment thickness and pile construction technical. The pile end resistence linearly increases with the settlement of pile end. In tis paper, the dead-load test is recommended in determination the pile bearing capacity and the sediment thickness should be strictly controlled in order to meet the standard. In the intermediary weathered sand-mudstone, the pile end should inset two times of pile diameter for pile whose diameter is 800mm. The pile end should inset 2 meters for pile whose diameter is 1500mm.

A Load-Testing Program on Large-Diameter (66-Inch) Open-Ended and PSC-Instrumented Test Piles to Evaluate Design Parameters and Pile Setup

2018 ◽  
Vol 2672 (52) ◽  
pp. 291-306 ◽  
Author(s):  
Md. Nafiul Haque ◽  
Murad Y. Abu-Farsakh ◽  
Chris Nickel ◽  
Ching Tsai ◽  
Jesse Rauser ◽  
...  
Keyword(s):  
Static Load ◽  
Large Diameter ◽  
Load Test ◽  
Design Parameters ◽  
Soil Conditions ◽  
Load Testing ◽  
Static Load Test ◽  
Testing Program ◽  
Tip Resistance ◽  
Load Tests

This paper presents the results from a pile load testing program for a bridge construction project at Chalmette, Louisiana. The load testing includes three 66-in. spun-cast post-tensioned open-ended cylinder piles and one 30-in. square prestressed concrete (PSC) pile driven at four different locations along the bridge site in clayey-dominant soil. Both cone penetration tests and soil borings/laboratory testing were used to characterize the subsurface soil conditions. All test piles (TP) were instrumented with strain gauges to measure the load distribution along the length of the TPs and to measure the side and tip resistances, separately. Dynamic load tests (DLT) were performed on all TPs at different waiting periods after pile installations to quantify the amount of setup (i.e., increase in pile resistance with time). Case Pile Wave Analysis Program (CAPWAP®) analyses were performed on the DLT data to calculate the resistance distributions along the TPs. A static load test was performed only on the PSC pile and statnamic load tests (SNLT) were conducted on both pile types. Design parameters such as the total stress adhesion factor, α, and the effective stress coefficient, β, were back-calculated. The α values ranged from 0.41 to 0.86, and the β values ranged from 0.13 to 0.29. The load test results showed that SNLT overestimated the tip resistance as compared with dynamic and static load tests. Moreover, the pile tip resistance was almost constant during the testing period, and setup was mainly attributed to increase in pile side resistance with time.

Lateral Load Test for Large Diameter Drilled Shafts for the Kosciuszko Bridge Replacement

2019 ◽  
Author(s):  
Daniela Bastos Zellers ◽  
Sherif Hanna ◽  
Matteo Ferrucci ◽  
Robert Adams ◽  
Jeff Moryl
Keyword(s):  
Large Diameter ◽  
Lateral Load ◽  
Drilled Shafts ◽  
Load Test

scholarly journals LARGE DIAMETER PILE LOAD TEST WITH A CASE STUDY USING OSTERBERG - CELL

2018 ◽  
Vol 30 (1) ◽  
Author(s):  
S. K. Bagui ◽  
B. C. Dinesh ◽  
Khan Md. Kamal ◽  
Ahsan Ahmad Sharif Shajib ◽  
Inthaqab Wahid Ruso
Keyword(s):  
Large Diameter ◽  
Load Test ◽  
Silty Sand ◽  
Load Testing ◽  
Downward Movement ◽  
Loading Test ◽  
Static Loading Test ◽  
Reverse Circulation ◽  
Pile Load Test

Static loading test using single level bidirectional –Cell was tested in March 2017 atPaira bridge in Bangladesh for initial load testing. Soil consists of soft silt with traced clay from0.0 m to 10.5 m underlain by various layer with very dense silty sand at the toe level and below.Pile was constructed reverse circulation method. Drilling slurry was composed of bentonite sluryfor 2.5 m diameter pile. The load cells were attached to a reinforcing cage at 18 m above toe.Static load test was 28days of casting the pile and tested. Testing was carried as per ASTM 1143with load increment 7.5 % estimated ultimate load. It was observed that downward movement ofreaching 220 mm and locked downward movement and O-Cell was given force for upwardmovement to find out skin fraction. Detailed analysis was carried out and it was found thatultimate load consisted of 49 MN skin frication and 30 MN end bearing sand safe design loadwas calculated as 33 MN.

The Test Analysis of the Bearing Capacity of Foundation

2014 ◽  
Vol 962-965 ◽  
pp. 357-360
Author(s):  
Ya Jun Yin ◽  
Xue Wen Xie ◽  
Yong Mei Qian
Keyword(s):  
Bearing Capacity ◽  
Standard Penetration Test ◽  
Test Methods ◽  
Test Point ◽  
Load Test ◽  
Test Method ◽  
Penetration Test ◽  
Loading Test ◽  
Test Analysis ◽  
Foundation Soil

The test method of shallow plate load was used in the bearing capacity of foundation of Yushu City , doing two groups of loading test in different depths and doing survey and comparative test between test point nearby and sites in the same horizon.It gets the law of foundation soil bearing capacity value got by different test methods and provides the basis for Jilin Province to establish the local standards through the comparison of load test and geotechnical test , static cone penetration test and standard penetration test.

Study of Ultimately Loading of Pile Foundation by Strength Reduction Method of No-Linear Limit Analysis of FEM

2010 ◽  
Vol 168-170 ◽  
pp. 2537-2542
Author(s):  
Tian Wen Dong ◽  
Ying Ren Zheng ◽  
Lian Zhuang Huang ◽  
Gang Chen
Keyword(s):  
Limit Analysis ◽  
Pile Foundation ◽  
Reduction Method ◽  
Large Diameter ◽  
Equivalent Plastic Strain ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Loading Test ◽  
Static Test ◽  
S Curve

For judging the security of pile foundation, the loading static test is popularly used in engineering. Some conditions could confine this method to estimate the ultimately loading according with objectivity, for example the high loading bearing pile foundation, the especial condition of static test, over length pile, etc.. So the strength reduction method (SRM) is put research this question in the basis of the ultimate loading capacity theory of pile foundation and the limit analysis of FEM. The judging condition and the safety storage factor (SSF) of SRM were built. The judging condition have three item, (1) the inflexion lies on F-s curve, and the bottom of F-s curve is parallel to the s axis; (2) the point of V type appear on F-Qu curve, so the previous reduction factor of this inflexion of F-s curve and the point of V type of F-Qu curve is SSF on the loading condition of pile head; (3) the equivalent plastic strain connected in soils around pile shaft and pile end. This method was used to analyze and estimate the ultimately loading of the large diameter pile, and its error of SRM to the static loading test and the increment loading method of FEM (ILM) are less 5%. So it shown that SRM may be used to attempt in engineering for judging the security of pile foundation and computing the ultimately loading.

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