The Influence of End Restraint on the Compression Strength of a Cohesionless Soil

作者：Alan W. Bishop, Gordon E. Green · 发表于：Géotechnique · 年份：1965 · DOI：10.1680/geot.1965.15.3.243 · 被引用次数：155 · 研究领域：Geotechnical Engineering and Soil Stabilization、Geotechnical Engineering and Underground Structures、Geotechnical Engineering and Soil Mechanics

Synopsis Tests have been carried out on a cohesionless soil to examine the influence of boundary restraint on the observed strength and on the relationships between stress, strain and volume change. To eliminate extraneous errors the axial load in the triaxial compression test has been measured by means of a sensitive proving ring situated within the cell. The proving ring has been calibrated from time to time during the series of tests by a hydraulic system operated by the same dead-weight pressure gauge tester as was used to calibrate the gauge measuring the fluid pressure in the cell. Cylindrical compression tests have been carried out with unlubricated plattens and with one or more layers of rubber membrane lubricated with silicone grease interposed between the ends of the sample and the loading plattens. Samples with three different ratios of height to diameter have been tested. The results indicate that, for the material tested, the effect of end restraint is to increase the apparent strength of the sample, but that this effect decreases with increasing height to diameter ratio and is of little significance with the usual ratio of about 2 to 1. For lower ratios the influence of end restraint on strength is more important and only with very efficient lubrication can the apparent strength of short samples be reduced to that given by samples with the standard height to diameter ratio. Des essais ont été effectués sur un sol non cohérent pour examiner l'influence de la rest...