ESTIMATION OF THE CRITICAL HEIGHT OF AN UNSUPPORTED VERTICAL TRENCH IN UNSATURATED SOILS
(0) Steep slopes and vertical trenches in several scenarios remain in a stable condition in unsaturated soils due to the contribution of matric suction. Recent studies show that steep slopes or vertical trenches that are stable generally fail due to the loss of matric suction associated with infiltration conditions prior to reaching saturated condition. The conventional methods that are used in the analysts with respect to stability of slopes or vertical trenches in unsaturated soils do not provide realistic estimates. In this paper, stability of an unsupported vertical trench in an unsaturated soil is analyzed taking account of the contribution of matric suction towards stability as an additional cohesion component by either estimating φb (i.e. angle indicating the rate of increase in shear strength relative to the matric suction) or using the shear strength parameters from constant water content (CW) tests for unsaturated soils (i.e. c and φ). The value of φb was indirectly estimated using the Soil-Water Characteristic Curve (SWCC) and the effective internal friction angle (i.e. φ). The approach presented in this paper is tested using the published results of a full scale instrumented test trench at the site of BBRI at Limelette, Belgium. The study shows that the stability analysis undertaken using the shear strength parameters from CW tests is more consistent with the field behavior results.
unsupported vertical trench unsaturated soil stable depth matric suction
S.K. Vanapalli H. Shen W.T. Oh
Civil Engineering Department, University of Ottawa, Ontario, Canada Civil Engineering Department, University of Ottawa, Ontario, Canada School of Civil Engineering and
国际会议
上海
英文
281-289
2009-08-24（万方平台首次上网日期，不代表论文的发表时间）