摘要:

The thermal consolidation of unsaturated soils in a thermo-hydro-mechanical framework is studied in a thermal triaxial apparatus described in the paper. The results of the first tests performed, under a given state of stress, on both silty and clayey soils, show some similarities between purely thermal consolidation and mechanical consolidation on saturated soils.Key words: unsaturated soils, temperature, triaxial, consolidation. [Journal translation]

ISSN:0008-3674    

DOI:10.1139/t90-011

出版商:NRC Research Press    

年代:1990

数据来源: NRC

摘要:

The transport mechanism of some rock avalanches of the Mackenzie Mountains in the Yukon and Northwest Territories of Canada is reassessed on the basis of evidence collected during fieldwork and by comparison with results from numerical simulations of the debris flow mechanism. A new hypothesis of glaciation-related transport is advanced as an alternate explanation of apparently very mobile rock avalanches with anomalous travel distances. By the example of the Avalanche Lake slide, it is demonstrated that the debris was most likely not deposited on the current topography but on valley glacier ice at an elevation of about 400–500 m above the valley bottom. This conclusion is supported by field evidence, an empirical runup relationship, and the results from numerical flow simulations. A qualitative interpretation of other debris deposits suggests that several events in the Mackenzie Mountains can be interpreted in the same manner.Key words: rock avalanches, rock slides, debris transport, debris flow modelling, Mackenzie Mountains, Northwest Territories.

ISSN:0008-3674    

DOI:10.1139/t90-012

出版商:NRC Research Press    

年代:1990

数据来源: NRC

摘要:

This note is concerned with the multiplicity of solutions for the factor of safety that may be obtained on the basis of the method of slices. Discontinuities in the function for the factor of safety are discussed and the reasons for false convergence in any iterative solution process are explored, with particular reference to the well-known Bishop simplified method (circular slip surfaces) and Janbu simplified or generalized method (slip surfaces of arbitrary shape). The note emphasizes that both the solution method and the method of searching for the critical slip surface must be considered in assessing the potential for numerical difficulties and false convergence. Direct search methods for optimization (e.g., the simplex reflection method) appear to be superior to the grid search or repeated trial methods in this respect. To avoid false convergence, the initially assumed value of factor of safetyF0should be greater than β1(=−tan α1tan) where α1andare respectively the base inclination and internal friction angle of the first slice near the toe of a slope, the slice with the largest negative reverse inclination. A value ofF0 = 1 + β1, is recommended on the basis of experience. If there is no slice with a negative slope for any of the slip surfaces generated in the automatic, search process, then any positive value ofF0will lead to true convergence forF. It is necessary to emphasize that no slip surface needs to be rejected for computational reasons except for Sarma's methods and similarly no artificial changes need to be made to the value ofexcept for Sarma's methods.Key words: slope stability, convergence, limit equilibrium, analysis, optimization, slip surfaces, geological discontinuity, simplex reflection technique.

ISSN:0008-3674    

DOI:10.1139/t90-013

出版商:NRC Research Press    

年代:1990

数据来源: NRC

摘要:

Several charts exist for evaluating soil type from electric cone penetration test (CPT) data. A new system is proposed based on normalized CPT data. The new charts are based on extensive data available from published and unpublished experience worldwide. The new charts are evaluated using data from a 300 m deep borehole with wire-line CPT. Good agreement was obtained between samples and the CPT data using the new normalized charts. Recommendations are provided concerning the location at which to measure pore pressures during cone penetration.Key words: soil classification, cone penetration test,in situ, case history.

ISSN:0008-3674    

DOI:10.1139/t90-014

出版商:NRC Research Press    

年代:1990

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t90-015

出版商:NRC Research Press    

年代:1990

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t90-016

出版商:NRC Research Press    

年代:1990

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t90-017

出版商:NRC Research Press    

年代:1990

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t90-018

出版商:NRC Research Press    

年代:1990

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t90-019

出版商:NRC Research Press    

年代:1990

数据来源: NRC