Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 181-197). Also available in electronic version.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 244-251).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 176-183). Also available in electronic version.

No description available.

No description available.

Subsoiling and deep loosening are widely used to alleviate soil compaction but little is known about the mechanics of the compaction process. Further information is required on the process that soil goes through during compaction, along with the effect on the amount of soil compaction of various tyre configurations. Such information will allow more confident recommendations to farmers on the suceptability of their soil to compaction. Experimental work was conducted where the soil deformtions of a light textured soil were monitored throughout the whole soil mass. The deformations in the soil were caused by a loaded pneumtic tyre on the surface. In the experimental work, both the process of soil compaction and the final state of the soil following the passage of a wheel were monitored. The experiments showed that soil compaction on light textured soils is caused by a punch failure of the soil, therefore most of the compaction is confined to the area directly below the wheel. The experimental monitoring of soil deformations was a slow and complex process, drawing firm conclusions from the work was further complicated by the interactions of the input variables, such as load and contact length. In order to monitor the effect of individual inputs on soil compaction a thre dimensional mathematical model of the process was developed from Theories of Elasticity and a confined compression soil test. The model predicted the subsurface deformations in the three principle directions due to surface loads. Once the model was modified to account for the support capability of the soil it proved it could, with resonable accuracy, predict the defomations and hence soil canpaction due to a tyre on the soil surface. The model was used to predict the effect of various tyre configurations on soil ccrnpaction. From a number of these runs it was possible to find the sensitivity of soil to compaction due to that input. The results showed that the sensitivity of soil to ccmpaction is not a linear relationship and significant reductions in the amount of soil, canpacted and the level of ihe compaction can be achieved by the right tyre configuration.

The objective of this research work was to gain a better understanding of the interaction between loads applied on the surface of soils, and the behaviour of adjacent long, vertical piles, embedded at depth in a stiff substratum. The influence of lateral thrust on the piles in an upper soft clay layer, due to simulated embankment construction, was examined and soil- pile interaction mechanisms were identified both for behaviour at working load and at the ultimate lateral capacity. The performance of a row of free headed piles and of a pile group were investigated experimentally in the geotechnical centrifuge for different pile and foundation geometries. Pile response, in terms of bending moment, deflection and lateral pressure, was determined for surcharge loads applied to the centrifuge model. This experimental database was used to calibrate a three dimensional finite element analysis of the same, simplified, model. These investigations led to the development of an approximate formula for lateral loading, based on the differential movement between the piles and the surrounding soil, which accounted for pile spacing, relative pile-soil stiffness and the degree of soil strength mobilisation. This loading function was incorporated in a computer program, SIMPLE, which calculated the pile bending moment and deflection profiles for flexible piles and pile groups. The algorithm was checked against the centrifuge model test results and the numerical analyses, and design charts were produced for free headed piles only. Finally a design procedure was recommended for piled full-height bridge abutments and other facilities which feature passive lateral loading of piles by a nearby surcharge.

No description available.

No description available.

No description available.