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

2006 ◽  
Vol 43 (2) ◽  
pp. 187-209 ◽  
Author(s):  
J Graham

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.

2018 ◽  
Vol 219 ◽  
pp. 05003
Author(s):  
Kamila Międlarz ◽  
Lech Bałachowski

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.


2012 ◽  
Vol 204-208 ◽  
pp. 107-114
Author(s):  
Ren Ping Li ◽  
Jie Liu

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.


2000 ◽  
Vol 37 (4) ◽  
pp. 796-810 ◽  
Author(s):  
F Schnaid ◽  
J AR Ortigao ◽  
F M Mántaras ◽  
R P Cunha ◽  
I MacGregor

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.


Author(s):  
Marek Bajda ◽  
Edyta E. Malinowska

Abstract The overconsolidation ratio of eemian gyttja determination. The overconsolidation ratio is an important parameter that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behavior and characteristics. To know the relation between geological background, history and mechanical behavior of the soil, aims a knowledge that can help engineers who often have to predict soil behavior based upon the soil geological history and a geotechnical data. In order to evaluate the overconsolidation ratio of eemian gyttja, it is necessary to restore this soft soil as much as possible to the in situ conditions. The eemian gyttja is an organic soft soil from the “Zoliborz channel” located in Warsaw. These soils are used as a base construction in the foundation engineering. In practical geotechnical engineering, evaluation of stress history is based on the overconsolidation ratio. The overconsolidation ratio is one of the basic parameters for the geotechnical design of the structure. Determination of this parameter using for example dilatometer tests, is usually based on empirical formulas which were established in different countries. Therefore, regional geotechnical conditions could have substantially affected on the empirical relationships. The laboratory tests are used to determinate the preconsolidation pressure and then the overconsolidation ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The paper presents results of determination the overconsolidation ratio of eemian gyttja from the laboratory and in situ tests. The studies have shown that the values of the overconsolidation ratio determination from the laboratory tests are a little higher than determination from the in situ tests.


1990 ◽  
Vol 27 (2) ◽  
pp. 167-176
Author(s):  
R. G. Campanella ◽  
R. Hitchman ◽  
W. E. Hodge

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.


2013 ◽  
Vol 50 (3) ◽  
pp. 259-274 ◽  
Author(s):  
Tien H. Wu

This paper reviews analytical models that are used to evaluate results of laboratory and in situ tests on soil reinforced by vegetation roots and performance of slopes with vegetation. Predicted and observed performances are compared to illustrate the accuracy and refinement of the models and their relationships to the quality of the available data. General guidelines for application to design problems are provided.


1993 ◽  
Vol 333 ◽  
Author(s):  
M. J. Plodinec ◽  
G. G. Wicks

ABSTRACTAn extremely important question for the eventual disposal of glass in natural environments is the relevance of laboratory testing of glass durability to the long-term performance of glass in geologic environments. The purpose of this study was to attempt to provide an empirical answer to that question, by applying the hydration thermodynamics approach (which has successfully been applied to laboratory tests of glass durability) to the results of longer-term testing in natural environments.The results show that hydration thermodynamics is a useful tool for explaining the effects of glass composition observed in in-situ tests, in several environments. Thus, it appears to provide a link between laboratory tests of glass durability and the results of in-situ tests in natural environments. Perhaps the most important conclusion of this effort is that the in-situ test results emphasize the importance of control of chemical composition during glass production as a means of achieving a durable glass.


2019 ◽  
Vol 284 ◽  
pp. 04001
Author(s):  
Łukasz Drobiec ◽  
Paweł Piotrkowski

The paper describes damages, tests and repair of the floor made on existing ceiling and expanded polystyrene concrete underlay. The floor was built on a reinforced concrete ceiling with an area of about 1050 m2. Significant damage in the form of cracks, detachments and unevenness was found in the floor. In order to determine the causes of damage, in situ tests and laboratory tests were carried out. It was found that the damage was caused by numerous performance errors. A test repair of the damage (4.7x6.0 m) was carried out, and then the repair method was applied on the entire floor surface.


Noise Mapping ◽  
2017 ◽  
Vol 4 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Luis Fernando Hermida Cadena ◽  
Antonio Carlos Lobo Soares ◽  
Ignacio Pavón ◽  
Luis Bento Coelho

AbstractThe assessment of soundscape implies an interdisciplinary approach, where objective and subjective aspects are considered. For the subjective evaluation, in situ and laboratory methodologies are usually followed. Local observations allow the collection of information on the influence of different stimuli present in the environment, whereas laboratory tests present a determined quantity of controlled stimuli to the evaluator. The purpose of this work is to compare results from the different methodologies in order to understand their strengths and their weaknesses. Three urban parks in the city of Lisbon, Portugal, were evaluated. Fragments of binaural sound recordings collected in the parks were used in laboratory tests to compare with the responses in situ and of expert and nonexpert listeners. Statistically significant differences were found in several of the perceptual attributes under observation, which led to variation in the results of the main model’s components. The sound environments were found to be more pleasant and uneventful in situ than in the laboratory, a phenomenon possibly due to the influence of other stimuli such as visual in the process of assessment. The in situ tests allow a systemic and holistic evaluation of the environment under study,whereas the laboratory tests allow a specific and tightly targeted analysis of different component sound events. Therefore, the two methodologies can be useful in soundscape assessment depending on the specific application and needs. No differences were found in the assessment made by either experts or nonexperts.


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