No description available.

This thesis is concerned with large strain soil consolidation and a large portion of the work is devoted to the theoretical development in modelling this phenomenon. An experimental programme based on a specially designed oedometer is also included. The governing equations are formulated in Chapter 2, where both the material and the space coordinates are considered. In space coordinate the problem is a moving boundary problem, and special numerical techniques for the idealized case of a thin soil layer are developed in Chapter 3. In Chapter 4 the consolidation of a normally consolidated stratum and a dredged fill are considered with a linear soil model, and the consolidation of a deposit undergoing continuous sedimentation is considered in Chapter 5. The material coordinate is used in the analysis which also includes the effect of self weight of soil. These problems are again considered in Chapter 6 and Chapter 7 with a nonlinear soil model. A specially designed oedometer for testing very soft soil is described in Chapter 8, and the experimental results are discussed in Chapter 9. These are compared with the theoretical solutions developed in Chapter 3, and good agreement has been obtained.

Thesis (Ph.D.)--University of Western Australia, 2006.

Thesis (M. Eng.), Memorial University of Newfoundland, 1999. / Bibliography: p. 116-119.

Thesis (Civ.E)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1982 / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 585-594. / by Imad Botros Ghantous. / Civ.E

No description available.

A field study was conducted in the fall of 1982 to investigate the effect of vehicle type, traffic moisture level, and their interactions on soil compaction. During the study two procedures commonly used for soil bulk density determination were also compared. Treatments at the following levels were applied: i) Soil moisture: Two levels ii) Vehicle type: wheel and track type iii) Traffic intensity: 0, 1, 3, and 9 passes. Each treatment combination was replicated three times and these were installed in random order on 48, 6 x 30 m test plots. Soil samples were taken at three locations from each test plot for the determination of moisture level. Core samples were taken in and outside the rut at three locations along each track for bulk density determination. Bulk density data using a double probe nuclear densitometer were taken at one location along the track. Statistical analysis of the data indicated that, of the factors considered in the study, number of vehicle passes and interactions between moisture level and vehicle type and number of passes and vehicle type had a significant effect on the compaction of the top soil layer. The two methods for measuring soil density were compared using the paired student's t-test and an equation was developed relating the density values obtained by nuclear and gravimetric procedures. Comparison of the data from the two methods indicated that the nuclear densitometer underestimated the core bulk density. / Master of Science

Soil compression is a topic of increasing importance in the evaluation of foundation sites for the heavy, rigid structures being founded upon them. The first analytical approach to compressive behavior in soil was presented by Terzaghi in the 1920's. Since that time, his consolidation theory has formed the general basis for prediction of soil compressibility under load. Compressive behavior not explained by Terzaghi’s assertions is known to occur in soils. These aberrations may be broadly classified into three categories: (1.) Initial or Elastic Deformation, (2.) Secondary time effects, and (3.) Compression rate discontinuities not attributable to the exuding of water from the soil skeleton. This study attempts to explain such anomalistic behavior in terms of electrochemical characteristics of the clay-water system observed subsequent to acceptance of the consolidation theory. The proposed mechanistic model of soil compression amends to Terzaghi’s considerations the internal energy consumed in the generation and degeneration of electrochemical bond. Such bond is the result of the electrochemical charges on clay mineral particles coupled with the strong polarity of water molecules. Under the influence of these electrochemical forces, each water molecule has a unique position and orientation commensurate with the condition of minimum potential energy. For relative movement to occur among clay particles or within the molecular water structure, electrochemical forces must be overcome at the expense of the clay-water system's internal energy, thereby creating an intergranular bond of structural water. The bond process model considers soil compression to be an aggregate response of bond creep, bond rupture, and bond formation, which may or may not be joined by consolidation as a controlling factor. The model illustrates initial compression and compression rate discontinuities as bond creep/bond rupture manifestations and secondary compression as the outgrowth of bond formation. Implications are also made which attribute compression time-lag as much to the rheologic properties of the soil skeleton as to resistance to water flow as asserted by Terzaghi. The findings of an experimental program are presented to substantiate the proposed model. Included in the findings are the results of three individual studies. The first study involves the visual inspection of compression curves from a representative group of undisturbed samples from throughout the United States. In keeping with the implications of the bond model, stress history appears to be a primary factor in control of soil compression and in the motivation of anomalous compressive behavior. Secondly, the influence of temperature upon compression characteristics was studied in detail. The findings illustrate the effect of temperature action on the colloid system which in turn affects bonding energies. Temperature influence is considered to be representative of the effect of various parameters on the distribution of net electrochemical potential in the colloid system. The final study entails determining the action of soil plasticity on soil time response. Comparison of compression curves from soils of similar characteristics, with the exception of plasticity, suggests that plasticity is coupled with permeability in controlling compression rate. / Ph. D.

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Civil Engineering, 1977 / Vita. / Sc. D. / Sc. D. Massachusetts Institute of Technology, Department of Civil Engineering

Typescript (photocopy). / Digitized by Kansas Correctional Industries