兰州理工大学学报

兰州理工大学学报 ›› 2020, Vol. 46 ›› Issue (1): 118-122.

• 建筑科学 • 上一篇    下一篇

基于不同土体本构模型的黄土地区深基坑稳定性分析及评价

周勇1,2, 苏天涛1,2   

  1. 1.兰州理工大学 甘肃省土木工程防灾减灾重点实验室, 甘肃 兰州 730050;
    2.兰州理工大学 西部土木工程防灾减灾教育部工程研究中心, 甘肃 兰州 730050
  • 收稿日期:2018-08-04 出版日期:2020-02-28 发布日期:2020-06-23
  • 作者简介:周 勇(1978-),男,侗族,湖北宣恩人,博士,教授,博导.
  • 基金资助:
    国家自然科学基金(51568042),教育部长江学者和创新团队发展计划项目(IRT-17R51)

Stability analysis and evaluation of deep foundation pits in loess region based on constitutive models of different soils

ZHOU Yong1,2, SU Tian-tao1,2   

  1. 1. Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou Univ. of Tech. , Lanzhou 730050, China;
    2. Engineering Research Center of Disaster Prevention and Mitigation in Civil Engineering of The Western, The Ministry of Education, Lanzhou Univ. ofTech. , Lanzhou 730050, China
  • Received:2018-08-04 Online:2020-02-28 Published:2020-06-23

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摘要： 选择两种不同假定的土体本构模型:H-S模型和M-C模型,借助PLAXIS有限元软件进行黄土地区深基坑的稳定性分析,并与条分法计算结果做对比.总结出如下结论:由于H-S模型相较于M-S模型在卸荷时表现得更硬,更能体现黄土较好的直立性与较高的强度,得出的安全系数更高,更适合黄土地区基坑稳定性分析;预应力锚杆的施工改变了土体的位移场和应力场,使得潜在滑移面向着土层深处发展,显著提高了基坑的稳定系数,对于基坑稳定有极大的贡献;相较于传统条分法,强度折减法具有很强的优势,不用划分土条并假定条间力和力矩,直接对土体参数的折减更符合实际情况,得出的安全系数更精确,更能反映土体滑移面的形成过程.

关键词: 深基坑, 桩锚支护, 本构模型, 强度折减法

Abstract: Two soil constitutive models with different hypothesis are selected:H-S model and M-C model, and the stability analysis of deep foundation pits in loess area is performed by means of finite element software PLAXIS, and compared with the calculation results of the slicing method. The following conclusions are summarized: since the H-S model exhibits harder than M-C model in the case of unloading, so that it will better reflect its better uprightability and higher strength of the loess, the resulting safety factor is higher, which will be more suitable for the stability analysis of foundation pits in loess areas; the construction of prestressed anchor will change the displacement field and stress field of the soil, making the potential slip facing the depth of soil and significantly increasing the stability coefficient of the foundation pit, and greatly contributing to the stability of the foundation pit; the strength reduction method will have a strong advantage over the conventional strip method. It will not need to divide the soil strip and assume the force and moment among the strips. The direct reduction of soil parameters will be more in line with the actual situation, and the resulting safety factor will be more accurate and can better reflect the formation process of the soil slip surface.

Key words: deep foundation pit, pile anchor support, constitutive model, strength reduction method

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