直接剪切试验及应用

Viewpoint of Direct Shear Test and its Applications

依据直接剪切试验理论,结合室内直接剪切试验经验,从直接剪切试验方法、影响直接剪切试验的因素、试验成果数据的解析等方面,探讨不同土质直接剪切试验方法的选择及成果应用。提出试验方法的选取应结合土质、施工时间长短、排水等因素综合考虑。建议20m深度以下的土层及粉土和粉砂不适宜做常规直接剪切试验;设计者在使用抗剪强度指标时不要片面的认为某些指标异常将其舍弃,而应与所取土样的地貌单元及地层结构对应起来使用该指标,这样更能反映土体的真实状况。

This article discusses the selections of direct shear test methods to different soil qualities based on the theory of direct shear test, combining the experience of indoor direct shear test, from the methods of direct shear test to the influence factors on direct shear test and to the resolutions of experimental results data. It proposes that the selections of experiment methods should comprehensively take the factors, such as soil quality time length of construction and dewatering into consideration. It suggests that the soil layers under depth of 20 meters, powder soil and powder sand are unfit for regular direct shear test. Also suggests that the designers should not unilaterally consider some indexes abnormal and abandon them while using the shearing strength indexes, but should use the indexes together with geography unit and geologic strata structures of the sampled soil,it can better reflect the true condition of soil in thus way.