长江科学院院报 ›› 2016, Vol. 33 ›› Issue (9): 66-71.DOI: 10.11988/ckyyb.20150542

• 岩土工程 • 上一篇    下一篇

复杂斜坡动力响应特征分析

刘勇,王运生,唐起,陈怡西   

  1. 成都理工大学 地质灾害防治与地质环境保护国家重点实验室,成都 610059
  • 收稿日期:2015-06-29 修回日期:2015-08-05 出版日期:2016-09-25 发布日期:2016-09-22
  • 作者简介:刘 勇(1989-),男,四川广元人,硕士研究生,从事地质工程专业研究,(电话)18482176120(电子信箱)1039786137@qq.com。
  • 基金资助:
    中国地质调查项目(12120113010100)

Seismic Response of a Slope with Complex Shape

LIU Yong,WANG Yun-sheng,TANG Qi,CHEN Yi-xi   

  1. State Key Laboratory of Geohazad Prevention and Geoenvironment Protection,Chengdu University of Technology, Chengdu 610059, China
  • Received:2015-06-29 Revised:2015-08-05 Online:2016-09-25 Published:2016-09-22

摘要: 深切谷坡浅表部卸荷裂隙发育,风化强烈,致使浅表层成为非连续介质,出现介质性质差异,地震动响应由此变得复杂。通过对青川东山斜坡地震动监测数据进行分析,并结合适用于分析岩质边坡运动过程的非连续变形分析(DDA)方法对青川东山斜坡动力响应特征进行数值模拟,揭示了震中距、高程、震级、地形以及“丁”字形山体等因素对地震波峰值加速度(PGA)放大的影响。结果表明垂直山脊方向以及高程较高时的地震波峰值加速度放大倍数较大,可达6.12倍;在地形突出部位,地震波亦能得到一定程度的放大,放大倍数可达3.3倍;在“丁”字形山脊结合部位,PGA放大倍数会出现一定程度的减小。

关键词: 边坡工程, 动力响应, 放大系数, DDA, 峰值加速度, 突起率

Abstract: Unloading fractures developed well in the superficial part of deep valley slope and was strongly weathered, which made subcutaneous layer a non-continuum and led to dielectric property difference. Seismic response in this area is complicated. Taking Dongshan slope in Qingchuan city as an example, we firstly analyzed the seismic monitoring data, and then simulated the dynamic response characteristics of the slope by using discontinuous deformation analysis method which is suitable for the analysis of rock slope motion process. We revealed the influences of epicentral distance, elevation, magnitude , terrain and T-shaped mountains and other factors on seismic peak ground acceleration (PGA). The results indicate that the seismic peak acceleration amplification factor at vertical ridge direction and higher elevation is larger, reaching 6.12 times; on the protrusion part of the terrain, seismic wave can also get a certain degree of amplification, reach 3.3 times; in the T- shaped ridge binding site, the PGA amplification ratio will be reduced to a certain degree.which greatly deteriorate its engineering properties. Latest research indicates that the increase of suction and inhomogeneous distribution mainly lead to the shrinking and cracking of expansive soil. However, few experiments about the expansive soil shrinking consider the effect of boundary condition on the shrinking process. In this research, pure montmorillonite is taken as test material,and its shrinking process in the presence of glass and vaseline friction boundaries are tested at different temperatures. The computer image processing technique is employed to quantify the geometric structure and morphologic characteristics of cracks. A conceptual model of shrinking and cracking of clay is established. Test results indicate that during the process of saturation-dehydration, cracks of specimens with vaseline-surface occur late and the critical water content of cracking is obviously lower than that of glass-surface specimens. At temperatures of 20℃, 30℃ and 40℃, the final amount of cracks of vaseline-surface specimen is smaller than that of glass-surface specimen by 70.3%, 79.6% and 77.6%, respectively. Additionally, in the presence of the same boundary friction, the pore water evaporation accelerates and the final amount of cracks increases with the increasing of temperature.

Key words: slope engineering, dynamic response, amplification factor, DDA, peak ground acceleration (PGA), prominent terrain rate montmorillonite, shrinkage, crack, boundary friction effect, temperature effeect

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