Influence of installation method on the behaviour of rigid piles in clay subjected to moment and horizontal load

1987 ◽  
Vol 24 (1) ◽  
pp. 145-149 ◽  
Author(s):  
V. V. R. N. Sastry ◽  
G. G. Meyerhof
Keyword(s):  
Pressure Distribution ◽  
Key Words ◽  
Model Test ◽  
Horizontal Load ◽  
Soil Pressure ◽  
Pile Capacity ◽  
Pile Installation ◽  
Bored Pile ◽  
Pure Moment ◽  
Bored Piles

The lateral soil pressure distribution, pile capacity, and displacements of instrumented single rigid bored piles subjected to pure moment and horizontal load have been investigated. The influence of method of pile installation on the above parameters is studied by comparing the behaviour of bored piles with that of jacked piles. It was concluded that the method of installation has practically no effect so far as the net lateral soil pressures and pile capacity are concerned, but the displacements may be up to three times larger for a bored pile than for a jacked pile under working loads. Key words: clay, horizontal load, installation, model test, moment, pile.

Bearing capacity of rigid piles under eccentric and inclined loads

1985 ◽  
Vol 22 (3) ◽  
pp. 267-276 ◽  
Author(s):  
G. G. Meyerhof ◽  
V. V. R. N. Sastry
Keyword(s):  
Bearing Capacity ◽  
Soft Clay ◽  
Horizontal Load ◽  
Soil Pressure ◽  
Pile Capacity ◽  
Inclined Loads ◽  
Pure Moment ◽  
Load Tests ◽  
Rigid Model ◽  
Test Pile

The ultimate bearing capacity of instrumented vertical single rigid model piles in homogeneous loose sand and soft clay under vertical eccentric and central inclined loads has been investigated. The results of these load tests provide a more realistic lateral soil pressure distribution on the pile shaft and better theoretical estimates of pile capacity under pure moment and under horizontal load. For intermediate eccentricities and inclinations of the load, the bearing capacity can be obtained from simple interaction relationships between the axial load and moment capacities and between the axial and horizontal load capacities, respectively. The influence of lateral soil pressures due to installation of displacement piles in clay is examined in relation to the ultimate load of the pile. The analyses are compared with the results of model tests and some field case records. Key words: bearing capacity, clay, eccentric loading, horizontal load, instrumentation, model test, pile, sand.

Full-displacement pressuremeter method for rigid piles under lateral loads and moments

1987 ◽  
Vol 24 (4) ◽  
pp. 471-478 ◽  
Author(s):  
G. G. Meyerhof ◽  
V. V. R. N. Sastry
Keyword(s):  
Model Test ◽  
Reasonable Agreement ◽  
Lateral Pressure ◽  
Layered Soil ◽  
Horizontal Load ◽  
Ultimate Capacity ◽  
Lateral Loads ◽  
Inclined Loads ◽  
Pure Moment ◽  
Rigid Model

The results of full-displacement pressuremeter tests in beds of sand, clay, and layered soil have been used to estimate the lateral soil pressures, ultimate capacity, and displacements of instrumented rigid model piles under eccentric and inclined loads. Comparisons of these estimates with observations on the piles under horizontal load and pure moment have been made and reasonable agreement is found. The analyses are also compared with some field case records. Key words: bearing capacity, clay, displacements, horizontal load, lateral pressure, layered soil, model test, moment, pile, pressuremeter, sand.

Study on Lateral Earth Pressure of Anchored Retaining Wall

2013 ◽  
Vol 353-356 ◽  
pp. 312-317
Author(s):  
Ying Yong Li ◽  
Li Zhi Zheng ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Zhi Chao Xue
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Model Test ◽  
Retaining Wall ◽  
Field Tests ◽  
Earth Pressure ◽  
Soil Pressure ◽  
Gravity Retaining Wall ◽  
Lateral Earth Pressure ◽  
The Stability

In order to ensure the security of gravity retaining wall in the high fill subgrade, the design of gravity retaining wall with anchors is proposed,the characteristic of the new wall is that comment anchors are added to the traditional gravity retaining wall,by friction anchors provide lateral pull to the wall so the stability of the new wall is improved. Because of the constraints of anchors, the lateral free deformation is influenced and the soil pressure distribution is very complicated, field tests showed that soil pressure distribution is nonlinear and pressure concentrate in anchoring position. In order to reveal the supporting mechanism of retaining wall and propose the soil pressure formula, the model test of anchor retaining wall is made and numerical simulation is done. The results show that soil pressure appears incresent above the anchor and decreasing below the anchor, the soil pressre also grew larger away from the anchor proximal in the horizontal direction.

Reliability of bored pile foundations considering bias in failure criteria

2005 ◽  
Vol 42 (4) ◽  
pp. 1086-1093 ◽  
Author(s):  
L M Zhang ◽  
D Q Li ◽  
Wilson H Tang
Keyword(s):  
Reliability Analysis ◽  
Failure Criterion ◽  
Limit State ◽  
Failure Criteria ◽  
Design Codes ◽  
Pile Capacity ◽  
Resistance Factors ◽  
Bored Pile ◽  
Load Tests ◽  
Bored Piles

The failure of a pile is always defined by a certain failure criterion. Several different failure criteria are commonly used, and the pile capacity values associated with each of these failure criteria can be considerably different. For the sake of international harmonization, it is necessary to calibrate the reliability levels associated with various failure criteria and factors for loads and resistances. This paper aims to evaluate the effects of failure criteria and factors for loads and resistances on the reliability of single bored piles. The bias arising from failure criteria is described by a bias factor, which can easily be accommodated in a reliability analysis. A comprehensive database of static load tests of bored piles is utilized to evaluate the bias associated with several failure criteria. Five limit-state design codes for piles are investigated to illustrate the effect of the bias from failure criteria, the effect of factors for loads and resistances, and their combined effect. The results indicate that the bias from failure criteria has a significant influence on the reliability of piles. Similarly, the use of different factors for loads and resistances in various design codes can also cause considerable differences in the calculated reliability. As a result of these effects, the actual reliability levels of any two design codes, assuming the same nominal target reliability index, can differ considerably.Key words: bored piles, pile capacity, failure criterion, reliability analysis, load factors, resistance factors.

scholarly journals Methodology for calculating the stability of borehole walls in soft clay bases

2020 ◽  
Vol 10 (2) ◽  
pp. 258-263
Author(s):  
Dmitry V. Popov ◽  
Keyword(s):  
Soft Clay ◽  
Soil Mass ◽  
Mathematical Experiment ◽  
Physicomechanical Characteristics ◽  
Pile Installation ◽  
Bored Pile ◽  
Design Documentation ◽  
Bored Piles ◽  
The Stability

The study is aimed at developing a methodology for calculating the stability of walls of boreholes in soft clay bases during the bored pile installation, as well as determining the criteria for maintaining the geometric integrity of the borehole. As a result of the study, leading to clearly-defined requirements for the geometric and strength characteristics of the casing with the prescription in the design documentation and further implementation at the construction site, a reduction in cost indicators for the installation of bored piles is obtained. The presented methodology demonstrates the necessity of applying casing prior to drilling a bore-hole and, if applicable, for calculating the amount of compressive pressure for selecting the cross section according to the geometric and strength parameters ensuring geometric integrity. In the course of the study, the soil mass around the borehole was examined along with a determination of critical radius of the soil to specify the loss of borehole wall stability. Next, the geometric shape of the unstable soil, its weight and, cor-respondingly, pressure at any point on the outer surface of the casing was determined. The conducted mathematical experiment allows the introduction of a criterion for possible casing application in pile borehole drilling, as well as justifying the assumption concerning a relationship between the geometric characteristics of the borehole and the physicomechanical characteristics of the surrounding soil mass for the subsequent installation of the bored pile.

Numerical Simulation of Pile-Bucket Foundation under Horizontal Load

2012 ◽  
Vol 460 ◽  
pp. 169-174
Author(s):  
Wen Bai Liu ◽  
Liang Yang ◽  
Chen Xia Zhu
Keyword(s):  
Failure Surface ◽  
Horizontal Load ◽  
Soil Pressure ◽  
Passive Region ◽  
Deep Soil ◽  
Maximum Displacement ◽  
Bucket Foundation ◽  
Load Line ◽  
Soil Stress ◽  
Pressure Changes

The pile-bucket foundation is a new kind of foundation. In this paper, the ABAQUS software was used to analyze the soil displacement field and the soil stress field surrounding of the pile-bucket foundation under the multi-cycle horizontal loading. Under the horizontal load, the active area of soil separated from the basics; the passive region takes the shape of a parabolic ring of soil wedge rotate failure surface. The maximum displacement was in the direction of horizontal load line on the surface of soil near the bucket. Horizontal and vertical soil pressure changes are concentrated under the surface of the soil near the bucket, and the maximum horizontal soil stress was in the deep soil around the bucket. There is a point of inflection between 1/3 and 1/2 of the pile into soil , and the soil pressure that upper and lower the point increased in the opposite direction. The horizontal forced resistance of the foundation mainly distributed under the bucket and 1/2 of the pile into soil .The conclusion could provide a reference basis for the analysis of bearing mechanism and destruction characters of pile-bucket foundation

Driven cast-in-situ pile capacity: insights from dynamic and static load testing

2021 ◽  
Author(s):  
Kevin N. Flynn ◽  
Bryan A. McCabe
Keyword(s):  
Dynamic Load ◽  
Shear Stresses ◽  
Load Testing ◽  
Pile Capacity ◽  
Compression Load ◽  
Shaft Resistance ◽  
Pile Installation ◽  
Cast Concrete ◽  
Load Tests

Driven cast-in-situ (DCIS) piles are classified as large displacement piles. However, the use of an oversized driving shoe introduces additional complexities influencing shaft resistance mobilisation, over and above those applicable to preformed displacement piles. Therefore, several design codes restrict the magnitude of shaft resistance in DCIS pile design. In this paper, a series of dynamic load tests was performed on the temporary steel driving tubes during DCIS pile installation at three UK sites. The instrumented piles were subsequently subjected to maintained compression load tests to failure. The mobilised shear stresses inferred from the dynamic tests during driving were two to five times smaller than those on the as-constructed piles during maintained load testing. This was attributed to soil loosening along the tube shaft arising from the oversized base shoe. Nevertheless, the radial stress reductions appear to be reversible by the freshly-cast concrete fluid pressures which provide lower-bound estimates of radial total stress inferred from the measured shear stresses during static loading. This recovery in shaft resistance is not recognised in some European design practices, resulting in conservative design lengths. Whilst the shaft resistance of DCIS piles was underpredicted by the dynamic load tests, reasonable estimates of base resistance were obtained.

scholarly journals Determining the quantity of access tubes for quality control of bored pile concrete based on probability approach

2020 ◽  
Vol 14 (2) ◽  
pp. 76-86
Author(s):  
Bach Duong
Keyword(s):  
Quality Control ◽  
National Standard ◽  
Construction Process ◽  
Construction Stage ◽  
Probability Approach ◽  
Bored Pile ◽  
Defects Inspection ◽  
Concrete Quality ◽  
Bored Piles ◽  
Sonic Logging

Unexpected defects of concrete in a completed bored pile can arise during the construction stage. Therefore, post-construction testing of bored pile concrete is an important part of the design and construction process. The Cross-hole Sonic Logging (CSL) method has been the most widely used to examine the concrete quality. This method requires some access tubes pre-installed inside bored piles prior to concreting; the required quantity of access tubes has been pointed out in few literatures and also ruled in the national standard of Vietnam (TCVN 9395:2012). However, theoretical bases aiming to decide the required quantity of access tubes have not been given yet. A probability approach is proposed in this paper aiming to determine the essential quantity of access tubes, which depend not only on pile diameters, magnitude of defects, but also on the technical characteristics of CSL equipment. Keywords: access tubes; bored piles; CSL method; defects; inspection probability.

Numerical Simulation of Bored Pile-Soil Interface Shear Performance

2013 ◽  
Vol 438-439 ◽  
pp. 1427-1432
Author(s):  
Qian Xu Liao ◽  
Jin Cao ◽  
Jun Wei Tang
Keyword(s):  
Numerical Simulation ◽  
Clayey Soil ◽  
Frictional Resistance ◽  
Measured Data ◽  
Interface Shear ◽  
Bored Pile ◽  
Model Pile ◽  
Shear Performance ◽  
Bored Piles ◽  
Soil Interface

This paper derives a numerical simulation of direct shearing test and model pile test based on the measured data of bored piles. Characteristics of the interface between bored pile and soil around it are analyzed. Laws of the magnitude and the distribution range of point resistance and frictional resistance of the bored piles in granular and clayey soil are obtained and the mechanism on them is explained.

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