scholarly journals Determination of p-y curves for offshore piles based on in-situ soil investigations

2018 ◽  
Vol 219 ◽  
pp. 05003
Author(s):  
Kamila Międlarz ◽  
Lech Bałachowski
Keyword(s):  
Field Tests ◽  
Soil Parameters ◽  
Lateral Loads ◽  
Cohesionless Soils ◽  
In Situ Tests ◽  
Soil Stiffness ◽  
Soil Response ◽  
Direct Design ◽  
Offshore Piles

Offshore piles are subjected to complex loads with considerable lateral component. The pile-soil response to lateral loads can be described with the p-y method. For a given depth the load–deflection relationship is built to simulate the surrounding soil stiffness. This state-of-art paper presents a brief discussion of determination methods for the p-y curves using a standard approach based on the soil parameters derived from laboratory and in-situ tests or directly from field tests. The basic relationships for both cohesive and cohesionless soils are discussed. The advantage of direct design methods to describe the p-y curve relies in the reduction of necessary laboratory tests.

Initial DPSH Soil Test Results with Accelerometer Installed in the Probe Cone

2016 ◽  
Author(s):  
Kęstutis Kelevišius ◽  
Gintaras Žaržojus
Keyword(s):  
Soil Analysis ◽  
Cohesive Soil ◽  
Test Results ◽  
Cone Penetration ◽  
In Situ Tests ◽  
Soil Response ◽  
Dynamic Penetration ◽  
Dynamic Cone Penetration ◽  
Cpt Test

Dynamic penetration test (DPSH) is one of the large amount of soil in-situ tests are known. In world practice, this method usually used for granular soil investigations although it could be applied in cohesive soils. Correlation of received DPSH test results with soil properties is complex and often not reliable. Especially it becomes obvious after application in cohesive soil analysis. In most cases, correlation depends on soil response to dynamic cone penetration and deformation of dynamic sounding equipment. Measurement of cone accelerations allows precisely evaluate loss of hammer energy, displacement of the cone during strike and other parameters. Correlation of DPSH (measured acceleration of the cone) and CPT test results are presented in this article. In this article also presented studies of possibilities to determine dynamic soil characteristics.

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.

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.

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.

New equipment for densification of granular soils at depth

1990 ◽  
Vol 27 (2) ◽  
pp. 167-176
Author(s):  
R. G. Campanella ◽  
R. Hitchman ◽  
W. E. Hodge
Keyword(s):  
Field Testing ◽  
Independent Study ◽  
Soil Parameters ◽  
Granular Soils ◽  
In Situ Tests ◽  
River Sand ◽  
University Of British Columbia ◽  
A Site ◽  
The Phoenix

An in situ densification probe that employs the novel technique of simultaneous vibration and dewatering has been developed by Phoenix Engineering Ltd. to compact deep, loose, granular soils. It is believed that pumping water out of the soil during the densification process offers improved densification capability over systems operating with vibration alone. An independent study was undertaken by the In-Situ Testing Group at the University of British Columbia to evaluate the performance of the Phoenix system.A field testing programme was conducted at a site in Vancouver where hydraulic sand fill overlies a natural silt and then medium Fraser River sand. Characterization of the site and evaluation of the densification treatment process were achieved using in situ tests. Changes to soil parameters due to densification treatment were examined, taking into account the modification of stresses brought about by the vibro-drainage process. The study investigated the degree of densification achieved, the value of concurrent drainage, the zone of influence of a single compaction probe, and group effects. The study also compares the performance of the Phoenix machine with that of other vibrocompaction equipment. Key words: in situ, densification, soils, granular, probe, vibratory, drainage, compaction, R&D.

The 2003 R.M. Hardy Lecture: Soil parameters for numerical analysis in clay

2006 ◽  
Vol 43 (2) ◽  
pp. 187-209 ◽  
Author(s):  
J Graham
Keyword(s):  
Constitutive Modeling ◽  
Laboratory Tests ◽  
Soil Parameters ◽  
In Situ Tests ◽  
Design Problems ◽  
Time Effects ◽  
Stiff Clays ◽  
Numerical Tools ◽  
Wetting Time

Engineers in geotechnical practice work on increasingly complex problems with increasingly powerful numerical tools. Effective solutions to design problems need good information about the site and parameters (or functions) that describe how the soil will behave under the proposed loadings. These loadings can include heating, drying or wetting, time effects, and chemical changes as well as the more common structural loads. This paper outlines issues that need to be considered when laboratory tests are used to produce soil properties for use in numerical analyses. The focus is on soft to moderately stiff saturated clays. Similar considerations for in situ tests, stiff clays, and sands are not considered.Key words: clay, testing, characterization, properties, constitutive modeling.

scholarly journals Field Test and Numerical Simulation for Coordinated Deformation of New Subgrade and Old Embankment Adjacent to River

2018 ◽  
Vol 8 (12) ◽  
pp. 2334 ◽  
Author(s):  
Jihong Wei ◽  
Zezhuo Song ◽  
Yuxia Bai ◽  
Jin Liu ◽  
Debi Kanungo ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Research Work ◽  
Drainage System ◽  
Field Tests ◽  
Creep Model ◽  
Soft Ground ◽  
Band Model ◽  
In Situ Tests ◽  
Wall Model

With the development of the economy in China, original roads may be unable to cope with the existing traffic. The expansion of the old embankment is the core problem for road expansion. Soft foundation differential settlements and pavement cracking along the joint between the new subgrade and old embankment often emerge after construction, especially during the operational period of the road. The Binjiang Avenue Project in Nanjing, China, is taken as a research example in this paper, and a typical test zone of about 300.0 m in length was selected to conduct research work through in-situ tests. The coordinated deformations of the subgrade combined with the old embankment under conditions of consolidation by drainage were researched using in-situ tests and numerical modeling. During the process of numerical modeling, the vertical drainage system in the compressible soft ground layers was simplified to be represented as the drainage band model and the equivalent sand-wall model. In addition, a soft ground creep model was adopted to calculate the deformation of the subgrade with the construction process. A comparison of the results between field tests and numerical simulations was carried out. The results show that there is good uniformity for both. Based on the results, three indexes for the new and old subgrade, such as the differential settlement, total settlement and post-settlement, should be viewed as the basis for the design and construction of the new subgrade and old embankment. Additionally, it was found that the soft ground model, drainage band model and equivalent sand-wall model are all completely suitable for the numerical modeling of the soft ground reinforcement subgrade. These results also provide a theoretical basis for the construction method of similar projects.

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