scholarly journals Characteristics of Gravelly Granite Residual Soil in Bored Pile Design: An In Situ Test in Shenzhen

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Shuai Luan ◽  
Fenglai Wang ◽  
Tiehong Wang ◽  
Zhao Lu ◽  
Weihou Shui
Keyword(s):  
Back Analysis ◽  
Design Methods ◽  
Design Parameters ◽  
Residual Soil ◽  
In Situ Tests ◽  
Rotary Drilling ◽  
Construction Methods ◽  
Pile Design ◽  
Granite Residual Soil

Granite residual soil is widely distributed in south China and is treated as a special soil. Its design parameters in rotary drilling bored piles are a matter of debate due to lack of in-situ pile load tests. Back-analysis of test piles is a reliable means of studying the geotechnical capacity of granite residual soil for pile design. In this study, a series of in situ tests was conducted comprising six full-scale instrumented test piles in gravelly granite residual soil in Shenzhen to consider the effects of different construction methods. The six piles were constructed with three different rotary drilling methods. Two commonly used design methods were investigated in the back-analysis: the SPT and effective stress methods. The results of the loading tests and strain gauges were used to obtain the back-analyzed parameters of the ultimate shaft resistance and ultimate base resistance for gravelly granite residual soil with these two design methods.

Analysis of self-boring pressuremeter (SBPM) and Marchetti dilatometer (DMT) tests in granite saprolites

2000 ◽  
Vol 37 (4) ◽  
pp. 796-810 ◽  
Author(s):  
F Schnaid ◽  
J AR Ortigao ◽  
F M Mántaras ◽  
R P Cunha ◽  
I MacGregor
Keyword(s):  
Site Investigation ◽  
Friction Angle ◽  
Soil Parameters ◽  
Residual Soil ◽  
Residual Soils ◽  
In Situ Tests ◽  
Cemented Sand ◽  
Fundamental Parameters ◽  
Analysis Technique

This paper presents the analyses of the results of the site investigation programme carried out at the Kowloon Bay site in Hong Kong. The tests consisted of self-boring pressuremeter (SBPM), Marchetti dilatometer (DMT), and laboratory tests carried out in a granite saprolite, which can be described as a lightly cemented sand. The purpose of this research project is to stimulate the development of methods to interpret data obtained from tests in residual soils. In particular, the work aims to evaluate the analyses of the SBPM data through a curve-fitting technique. Both the loading and unloading portions of the SBPM curve were analysed and the results compared with those from other tests. The advantage of this analysis technique is the possibility of constructing a theoretical curve that reproduces a pressuremeter test from which a set of fundamental parameters can be derived, namely the friction angle, cohesion intercept, lateral stress, and shear modulus. The DMT proved to be a reliable tool that yielded good soil parameters at a small fraction of the cost of the other in situ tests.Key words: residual soil, in situ tests, pressuremeter, Marchetti dilatometer.

In situ tests in Brasília porous clay

1996 ◽  
Vol 33 (1) ◽  
pp. 189-198 ◽  
Author(s):  
J A.R Ortigao ◽  
R P Cunha ◽  
L S Alves
Keyword(s):  
Low Cost ◽  
Laboratory Data ◽  
Design Parameters ◽  
Residual Soils ◽  
In Situ Testing ◽  
In Situ Tests ◽  
Deformation Parameters ◽  
Strength And Deformation ◽  
Plate Loading

An in situ testing programme was carried out in 1992 aimed at obtaining design parameters for the construction of the Brasília Underground line, Brazil. The top layer of soil consisted of an unsaturated and collapsible soft porous clay layer 5–30 m thick followed by residual soils from slate and interlayered metasiltsones and quartzites. A series of Marchetti dilatometer (DMT) logging tests results were comapred with Ménard pressuremeter (PMT) and horizontal plate loading (PLH) tests, as well as laboratory tests on block samples. In situ stresses, strength, and deformation parameters were obtained for the porous clay. The DMT yielded very good results: excellent repeatability, low cost, and results that agree with other in situ tests and laboratory data. Key words: porous clay, in situ testing, dilatometer, pressuremeter.

scholarly journals Evaluation of Stiffness Degradation Curves from in Situ Tests in Various Soil Types

2018 ◽  
Vol 64 (4) ◽  
pp. 285-307
Author(s):  
T. Godlewski
Keyword(s):  
Field Tests ◽  
Shear Stiffness ◽  
Test Methods ◽  
Soil Types ◽  
Design Parameters ◽  
Design Calculation ◽  
In Situ Tests ◽  
Nonlinearity Test ◽  
Strain Dependent

AbstractIncreasingly complex design systems require an individual approach when determining the necessary design parameters. As soils are characterized by strong strain-dependent nonlinearity, test methods used to characterize the subsoil should be carefully selected, in terms of their “sensitivity” as well as suitability for the analyzed type of problem. When direct measurements are not available, while design calculation models require specific parameters, indirect parameter estimation may be used. This approach requires calibration and validation of empirical correlations, based on well documented database of tests and case studies. One of the parameters often used, when analyzing soil-structure interaction problems, is the shear stiffness of the soil and its strain-dependent degradation. The aim of the article is to present the procedure for description and evaluation of soil stiffness based on field tests (CPTU, DMT and SDMT) and a large number of reference curves obtained from laboratory tests (TRX) for selected soil types. On the basis of the given algorithm, it is possible to obtain a stiffness module G0 value at any level of deformation, based on in-situ tests.

Design Parameters for Offshore Sands: Use of In Situ Tests

1985 ◽  
pp. 269-292
Author(s):  
T. Lunne ◽  
S. Lacasse ◽  
G. Aas ◽  
C. Madshus
Keyword(s):  
Design Parameters ◽  
In Situ Tests

scholarly journals Estimation of Toe Load-Settlement Relation of Non-Displacement Piles Based on Back-Analysis of In-Situ Tests

2001 ◽  
Vol 41 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Hiroaki Nagaoka ◽  
Masahiro Yamazaki ◽  
Ying Zhang ◽  
Takeshi Okamura
Keyword(s):  
Back Analysis ◽  
In Situ Tests

Design parameters of granular soils from in situ tests

2020 ◽  
pp. 65-94
Author(s):  
Michele Jamiolkowski ◽  
Diego C.F. Lo Presti ◽  
Francesco Froio
Keyword(s):  
Design Parameters ◽  
Granular Soils ◽  
In Situ Tests

scholarly journals A proposed method to determine in-situ shear modulus and shear strain decay curves in different structured soil

2019 ◽  
Vol 92 ◽  
pp. 18004
Author(s):  
Ran An ◽  
Lingwei Kong ◽  
Aiguo Guo ◽  
Xianwei Zhang
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Soft Soil ◽  
Soft Rock ◽  
High Standard ◽  
Small Strain ◽  
Residual Soil ◽  
Resonant Column Test ◽  
Granite Residual Soil

This paper illustrates the application of the self-boring pressuremeter test and the seismic dilatometer test to acquire the in-situ decay curves of stiffness with shear strain level (G-γ decay curves) of three types of structural soil, which are granite residual soil, structural soft soil and expansive soft rock. The proposed approach in combines the functions of SBPT and SDMT to provide the high standard of accuracy for the small-strain stiffness (from SDMT) and the major attenuation stage of stiffness (from SBPT). Using the proposed mathematical model can properly describe the tendency in typical in-situ G-γ decay curves based on the data of tests. To analyse the suitability of the proposed approach, the G-γ curve obtain from the resonant column test of granite residual soil is also employed to compare with the in-situ curves. The shear modulus G obtained from laboratory tests is found to be smaller and the stiffness attenuation rate is found to be faster than the curve of the in-situ test, which reflects the process of sampling, transporting and preparation of soil samples could cause unrecoverable damages in soil.

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