基于改进拟动力法的新型热锚管框架冻土边坡体系稳定性分析  

Stability of Frozen Soil Slope System with New Thermal Anchor Based on Improved Pseudo Dynamic Method

作　　者：吴晓磊 董建华[1,2] 苏世林 郑亚林 WU Xiaolei;DONG Jianhua;SU Shilin;ZHENG Yalin(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[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

出　　处：《应用基础与工程科学学报》2023年第5期1243-1261,共19页Journal of Basic Science and Engineering

基　　金：中央引导地方科技发展资金项目(YDZX20216200001739);国家自然科学基金项目(51778275,52178335);陇原青年创新创业人才(团队)项目(2020RCXM120);兰州市十大科技创新项目(2020-2-11);甘肃省知识产权局高价值专利培育和转化项目(20ZSCQ034)。

摘　　要：为了更合理地评价新型热锚管框架冻土边坡体系在地震和冻融双重作用下的稳定性,首先推导了基于融土层弹性放大效应的加速度表达式;其次根据热量收支平衡原理给出热锚管作用下冻土边坡滑移面的位置;然后提出了基于热锚管锚固力应力扩散效应的双层介质附加应力等效模型;最后给出该冻土边坡体系稳定性的计算方法,并结合工程算例,将该方法与传统拟动力法、拟静力法对比分析,证明了改进拟动力法能够刻画热锚管框架冻土边坡体系的稳定性.结果表明,热锚管支护技术与热棒、锚杆技术相比,其防治冻土边坡的效果更好,且热锚管的锚固力越大,换热能力越强,冻土边坡体系的稳定性越好;由于波动效应的存在,抗震设计时须充分校核不同地震波振动频率的影响,尤其是与融化层自振频率相近的情况;采用该方法得到的沿坡高放大系数为非线性的,而采用传统拟动力法其结果是线性的,导致安全系数被高估,但采用改进传统拟动力法的放大系数后,也能取得与改进拟动力法相近的结果.该研究可为热锚管框架支护冻土边坡的抗震设计提供理论依据和新思路.To evaluate the stability of the frozen soil slope system of the new thermal anchor frame under the combined action of earthquake and freeze-thaw more reasonably.Firstly,the acceleration expression considering the elastic amplification effect of the melted soil layer was derived;Secondly,based on the principle of heat balance,the position of the sliding surface of frozen soil slopes under the action of thermal anchor is given;Then,an equivalent model for additional stress in double-layer media is proposed that can consider the stress diffusion effect of thermal anchoring force;Finally,the calculation method of the stability of the frozen soil slope system is given,and combined with the engineering calculation example,the proposed method is compared with the traditional pseudo dynamic method and the pseudo static method,which proves that the proposed method can describe the stability of the frozen soil slope system of the thermal anchor frame.The results show that compared with thermal rod and anchor rod technology,the thermal anchor support technology has a better effect on preventing and treating frozen soil slopes.The larger the anchoring force of the thermal anchor,the stronger the heat exchange capacity,and the better the stability of the frozen soil slope system;Due to the existence of wave effect,the influence of different seismic wave vibration frequencies must be fully checked in seismic design,especially when it is close to the natural frequency of melting layer;The amplification factor of slope height obtained by this method is nonlinear,while the traditional pseudo dynamic method is linear,which leads to overestimation of factor of safety.However,by improving the amplification factor term of the traditional pseudo dynamic method,similar results can be obtained with this method.The research can provide theoretical basis and new ideas for the seismic design of thermal anchor frame support for frozen soil slopes.

关 键 词：热锚管框架结构 冻土边坡 改进拟动力法 应力扩散效应 稳定性 

分 类 号：TU43[建筑科学—岩土工程]