scholarly journals Experimental Investigation on the Vertical Bearing Characteristics of Jacked Piles in Saturated Silt Foundations under Excavation

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Yong-Zhi Jiu ◽  
Zhen Zhang ◽  
Xiang-Yu Zhang
Keyword(s):  
Static Load ◽  
Stress Path ◽  
Load Test ◽  
Soil Consolidation ◽  
Static Load Test ◽  
Soil Pressure ◽  
Friction Resistance ◽  
System A ◽  
Loading System ◽  
Vertical Bearing

A model test system for vertical bearing characteristics of the jacked piles in saturated soil foundations under excavation has been introduced. The system device comprises a soil pressure loading system, a model pile loading system, a soil vacuum saturation system, a model box, a model pile, and a control and data acquisition system. The soil vacuum saturation system designed for the model box of this test device can ensure that the saturated soil in the model box can reach a higher degree of saturation. Loading and unloading were conducted on the soil sample in the model box through the soil pressure loading system to simulate the soil excavation so that the soil sample and that in the field have the same stress state and history. The soil consolidation pressure, pile jacking pressure, pile tip force, soil consolidation settlement, and pile displacement at the top were collected and monitored in real time through the control and data acquisition system. This device is used to conduct an experimental study on the bearing characteristics of the jacked piles in saturated silt foundations under excavation. The results indicate that the static load test increases the residual pressure on the tip of the jacked pile while also increasing soil stiffness at pile tip and ultimate tip resistance, thereby increasing the pile top stiffness and ultimate load-carrying capacity. However, when the jacked pile is left undisturbed for the same time, the static load test on the jacked pile does not affect the pile skin friction resistance. There is a better linear relationship between the pile skin friction resistance and the undrained shear strength of the soil under the corresponding stress path during the static load test of the normally consolidated soil and the jacked pile after overburden pressure unloading. There is a good linear relationship between the ultimate resistance and the undrained shear strength of the soil under the corresponding stress path in pile sinking, normally consolidated soil, and during the static load test on jacked pile after unloading.

Experiment Research on Bored Pile with Post-Grouting Technology

2013 ◽  
Vol 838-841 ◽  
pp. 854-857
Author(s):  
Rui Chao Cheng ◽  
Xin Yu
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Test ◽  
Static Load Test ◽  
Pile Head ◽  
Experiment Research ◽  
Friction Resistance ◽  
Bored Pile ◽  
Post Grouting ◽  
Side Friction

The bearing capacity characteristics and side friction characters of post-grouting pile were studied in the static load test which included two piles with post-grouting or not. When the pile head settlements were same, the loads applied on the pile top were used to analyze the bearing properties of post-grouting pile. We got the ultimate side friction of post-grouting pile after fitting test curves of relations between friction resistance and displacement. The tests indicate that both the bearing capacity characteristics and side friction of post-grouting pile are increased in various degrees.

Back-Analysis for Design Parameters of Large Diameter Bored Piles

2013 ◽  
Vol 671-674 ◽  
pp. 186-189
Author(s):  
Werasak Raongjant ◽  
Meng Jing
Keyword(s):  
Test Data ◽  
Load Transfer ◽  
Static Load ◽  
Large Diameter ◽  
Back Analysis ◽  
Load Test ◽  
Design Parameters ◽  
Static Load Test ◽  
Friction Resistance ◽  
Bored Piles

Field test data from three instrumented large diameter bored piles in Pattaya city of Thailand were analyzed to study the behavior of load transfer mechanism from the pile to soil. The pile load test data were obtained from conventional static load test. These bored piles used for conventional static load test have the same diameter of 0.80 m and different length in the range of 25 m to 32 m. Results from back-analysis found that the skin friction resistance, β, has the value between 0.20 and 0.64 and the bearing capacity at end of piles, Nq, which is in the range of 10 to150, is much lower than the theoretical values proposed by other researchers before.

scholarly journals A Novel Numerical Method for Calculating Vertical Bearing Capacity of Prestressed Pipe Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Rongbao Chen ◽  
Jichao Zhang ◽  
Zeyu Chen ◽  
Meixiang Gu
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Hard Rock ◽  
Soft Rock ◽  
Load Test ◽  
Static Load Test ◽  
Soil Layers ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity ◽  
Rock And Soil

A novel method for calculating the vertical bearing capacity of prestressed pipe piles with the acceptable error was proposed and verified. Soils at the pile side and end were, respectively, simulated by an elastic-plastic model and a new double-line (at soft rock and soil layers) or triple-line model (at hard rock and soil layers); then, a mechanical model was established for simulating vertical bearing capacity of prestressed pipe piles, and the corresponding calculation process was carried out. The values of pile side resistance, pile end resistance, and pile end elastic displacement were first obtained from the results of high-strain dynamic testing (HSDT) and then were imported into the proposed numerical model for calculating the vertical bearing capacity of prestressed concrete pipe piles. The static load test was carried out to verify the numerical results. Besides, 20 piles were tested at two typical test sites (soft and hard rock bearing strata), of which 8 piles were arranged at the soft rock bearing stratum site and 12 piles were arranged at the hard rock bearing stratum site. The numerical results achieved from an empirical formula were also used for making a comparison. The values obtained by the proposed method were highly close to those achieved from the static load test with an error of within 10%. The outcomes indicated that the proposed numerical method can be potentially applied to predict the bearing capacity of prestressed pipe piles.

scholarly journals MODELING OF THE JACKED PILE STATIC LOAD TEST WITH PLAXIS 3D / SPAUSTINIO POLIO BANDYMO STATINE APKROVA MODELIAVIMAS PLAXIS 3D

2016 ◽  
Vol 8 (5) ◽  
pp. 495-498
Author(s):  
Tautvydas Statkus
Keyword(s):  
Building Materials ◽  
Model Building ◽  
Static Load ◽  
Load Test ◽  
Static Load Test ◽  
Model Geometry ◽  
Comparison Of The Results ◽  
3D Software ◽  
Installation Technology ◽  
Plaxis 3D

In this article jacked pile installation technology and its current processes, altering the base physical and mechanical characteristics are discussed. For the jacked pile static load test simulation Plax 3D software was selected, the opportunities and developments were described. Model building, materials, models, model geometry, finite elements, boundary conditions and assumptions adopted in addressing problems described in detail. Three different tasks formulated and load-settlement dependence a comparison of the results with the experiment given. Conclusions are formulated according to the modeling results. Šiame straipsnyje aptarta spaustinių polių įrengimo technologija ir ją taikant vykstantys procesai, keičiantys pagrindo fizines ir mechanines charakteristikas. Spaustinio polio bandymui statine apkrova modeliuoti pasirinktas PLAXIS 3D programinis paketas ir aprašytos jo galimybės bei raida. Detaliai nupasakotas modelio kūrimas, medžiagų modeliai, modelio geometrija, baigtiniai elementai, kraštinės sąlygos ir priimamos prielaidos sprendžiant problemą. Suformuluoti trys sprendžiami uždaviniai ir apkrovos bei nuosėdžio priklausomybe pateikiamas rezultatų palyginimas su eksperimentu. Atsižvelgiant į modeliavimo rezultatus suformuluotos išvados.

Static Load Test of Frame-Structure Slab

2013 ◽  
Vol 790 ◽  
pp. 227-230
Author(s):  
Jian Feng Su ◽  
Yu Feng Xu
Keyword(s):  
Carrying Capacity ◽  
Static Load ◽  
Load Test ◽  
Frame Structure ◽  
Test Results ◽  
Static Load Test ◽  
Important Method ◽  
Floor Slab ◽  
Testing Scheme

Floor slab static load test is a important method to judge the performance and carrying capacity of the slab. This paper, with the background of a factory frame-structure slab, introduced the testing scheme, the details of the testing process as well as the test results. The testing cases provide a useful reference for the same type of project.

scholarly journals Comparison of Numerical Analyses with a Static Load Test of a Continuous Flight Auger Pile

2014 ◽  
Vol 22 (4) ◽  
pp. 1-10 ◽  
Author(s):  
Michal Hoľko ◽  
Jakub Stacho
Keyword(s):  
Load Distribution ◽  
Static Load ◽  
Numerical Models ◽  
Load Test ◽  
Numerical Analyses ◽  
Static Load Test ◽  
Material Models ◽  
The Common ◽  
Constitutive Material ◽  
The Impact

Abstract The article deals with numerical analyses of a Continuous Flight Auger (CFA) pile. The analyses include a comparison of calculated and measured load-settlement curves as well as a comparison of the load distribution over a pile's length. The numerical analyses were executed using two types of software, i.e., Ansys and Plaxis, which are based on FEM calculations. Both types of software are different from each other in the way they create numerical models, model the interface between the pile and soil, and use constitutive material models. The analyses have been prepared in the form of a parametric study, where the method of modelling the interface and the material models of the soil are compared and analysed. Our analyses show that both types of software permit the modelling of pile foundations. The Plaxis software uses advanced material models as well as the modelling of the impact of groundwater or overconsolidation. The load-settlement curve calculated using Plaxis is equal to the results of a static load test with a more than 95 % degree of accuracy. In comparison, the load-settlement curve calculated using Ansys allows for the obtaining of only an approximate estimate, but the software allows for the common modelling of large structure systems together with a foundation system.

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