›› 2016, Vol. 30 ›› Issue (3): 403-406.

• 工程实录 • 上一篇    

扰动土旁压试验初探

杨石飞   

  1. (上海岩土工程勘察设计研究院有限公司,上海 200070)
  • 收稿日期:2016-05-23 修回日期:2016-05-25 出版日期:2016-06-20 发布日期:2016-06-21
  • 作者简介:杨石飞(1977-),男,高级工程师,研究方向为岩土工程。
  • 基金资助:

    基金项目:上海市科委《地铁周边群体工程活动对地铁运营安全的影响研究》(10231203500)

Pressuremeters Tests in Disturbed Cohesive Soils

YANG Shifei   

  1. (Shanghai Geotechnical Investigation and Design Institute Co., Ltd., Shanghai, 200031)
  • Received:2016-05-23 Revised:2016-05-25 Online:2016-06-20 Published:2016-06-21

摘要: 扰动后土体强度和变形特性的研究非常重要,针对工程活动扰动及人为扰动多采用室内试验进行模拟,结果往往不具有可重复性,常规原位测试手段,仅能获得扰动土体强度变化,不能获得应力应变关系变化。以旁压试验方法研究土体扰动前后的强度和变形指标变化,对上海第④、⑤、⑥层粘性土在扰动前后分别进行旁压试验,研究不同土层扰动前后的强度和变形规律。从扰动前后的旁压试验对比发现,扰动后土体的强度有明显变化,初始压力、临塑压力以及旁压模量等均有明显下降,扰动对土体的变形规律也有较大影响,旁压试验弹塑性阶段的旁压曲线在扰动前后差别明显,极限体应变也产生明显下降。

关键词: 旁压试验, 扰动土, 应力应变关系, 原位测试

Abstract: It is practically important to characterize the strength and deformation of various disturbed soils. The state of the practice of studying the properties of disturbed soils are laboratory testing. However, laboratory tests have very limited repetitiveness. Some conventional insitu tests, such as, cone penetration tests (CPT) and vane shear tests (VST), can only obtain the strength parameters of disturbed soils and the deformation characteristics of these soils are not available. This paper presents the disturbed strength and deformation properties of the fourth, fifth and sixth layers of typical Shanghai cohesive soils by using prebored pressuremeters. The test results indicate that, an obvious strength decrease could be found in the disturbed soils in the initial pressure, the plastic pressure, as well as the pressuremeter modulus. In addition, the disturbance on the deformation property is also significant. The pressuremeter curves have significant different before and after the soil disturbance. The limit strain after soil disturbance reduces significantly.

Key words: Pressuremeter Tests, Disturbed Soils, Stress-Strain Relations, In-Situ Tests