1,720,983 research outputs found
Site investigation: A handbook for engineers
No full textSite investigation is the crucial first step in design and construction, when the cost and practicality of a project are evaluated. It is also a necessary part of the investigation of building failures. This major reference work describes the organization of site investigation, the plant, sampling equipment and interpretation of results. The second edition includes new material on specification and procurement, desk studies on geophysics, sample disturbance and sampling methods, in–situ testing and laboratory testing
The value of stiffness measured in field seismic surveys
No full textStiffness parameters are required for many geotechnical calculations, including numerical modelling using the finite element or finite difference methods. The measurement of stiffness is not trivial, yet the actual values of stiffness adopted during analyses can have a very significant impact on predictions, and hence the perceived viability of a project. Measurement of stiffness in the laboratory is now well established, using techniques such as advanced triaxial testing with local strain measurement, cyclic triaxial testing, and the resonant column apparatus. Field geophysical techniques, although not as well established, can add significantly to the determination of input parameters for deformation analyses and prediction. This paper considers the strengths and weaknesses of these methods, using examples from a range of projects and ground conditions, and discusses how seismic geophysics can most effectively contribute
Large diameter plate tests on weathered in-situ chalk
No full textThe prediction of the settlements of spread foundations on in-situ chalk is best carried out using empirical methods, based on the simple behavioural model developed by Burland & Lord (1970) using results from plate tests. However, the data available to support this approach remain somewhat limited, stratigraphically, geographically and in terms of size and level of loading. This paper reports the results of nine large (1.8 m) diameter plate tests carried out on three weathered chalks with widely different intact densities and strengths. The results are interpreted in terms of the Burland and Lord model, and despite the differences in the chalks at these sites, are found to be broadly in agreement with the parameters deduced on the basis of the pioneering work carried out at Mundford by Wardet al. (1968). In addition the paper provides some additional data on creep settlements, confirming that the long-term settlements on chalk can be considerably larger than those predicted on the basis of short-term loading tests
The use of field geophysical techniques to determine geotechnical stiffness parameters
No full textRecent advances in our knowledge of the geotechnical behaviour of natural soils and weak rocks suggest that the shear stiffness controlling wave propagation in near-surface materials will be similar to those which geotechnical engineers wish to measure, and use to calculate movements of the ground around engineering structures. Field seismic techniques which have been found suitable for stiffness determination are reviewed. The benefits of using geophysical methods, as compared with the use of routine geotechnical techniques, are discusse
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