多年冻岩土区露天矿边坡局部稳定性探究 - 论文

西安理工大学学报 Journal of Xi'an University of Techno logy (2019) Vol. 35 No. 153DOI： 10. 19322/j. cnki. issn. 1006-4710. 2019. 01. 009多年冻岩土区露天矿边坡局部稳定性探究李国锋1,李 宁I,2,刘乃飞3，朱才辉1(1.西安理工大学岩土工程研究所,陕西西安710048；.兰州交通大学土木工程学院，甘肃兰州730070；3.西安建筑科技大学土木工程学院,陕西西安710055)摘要：多年冻岩土区露天矿边坡具有特殊的地层分布，且坡表易受外环境周期性的影响而产生局

部滑塌或掏蚀破坏。本文沿用含相变的温度场、渗流场、应力场耦合(THM)简化算法和理想边坡

模型，探究了边坡冻融下局部损伤破坏演化过程，讨论了基于屈服接近度的局部稳定性分析评价方

法的实用性，并以此研究了各因素对边坡稳定性的影响。结果表明：拉塑性区会随着季融层回冻而

内移，坡体浅层有沿季冻层底冰面滑塌的可能，而坡肩内部是坡体整体安全性的受力关键，局部有

效屈服区综合了拉剪破坏的性质及其区域分布。冻结温度、坡高、冻融循环次数、热膨胀系数、孔隙 率对局部有效屈服区的影响程度依次减弱。其中，坡高、冻结温度、冻融次数主要导致坡体内部的

损伤积累，坡角更易导致坡表的破坏，而热膨胀系数、孔隙率将同时增大坡体的破坏区与损伤区。

关键词：局部稳定性；屈服接近度；露天矿边坡；多年冻岩土区中图分类号：TU445

文献标志码:A

文章编号:1006-4710(2019)01-0053-09Local stability of open-pit coal mine slope in permafrost regionsLI Guofeng1 , LI Ning1，2, LIU Naifei3 , ZHU Caihui1(1. Institute of Geotechnical Engineering,Xi?an University of Technology,Xi'an 710048 ,China；2. College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070 ,China；3. School of Civil Engineering,Xi?an University of Architecture and Technology,Xi'an 710055 ,China)Abstract： There is the special strata distribution in the slope of open-pit mine in permafrost re-

gions，andtheslopesurfaceispronetolocalcolapseorfailureduetotheinfluenceofexternal environment Thispaperexploresthedamagefailureevolutionprocess，discussesthepracticabili-

tyofthelocalstabilityanalysisevaluationmethodbasedontheyieldapproachindex，andresear- chesvariousinfluencefactorsbythecoupledthermo-hydro-mechanical (THM) simplifiedalgo- rithm and the ideal model. Results show that the new tension plastic zone may internally move as backfreezingonseasonalfrozenlayer，andtheshalowlayeroftheslopehasthepossibilityof

sliding along the bottom of the seasonal frozen layer. The internal of slope shoulder is the key to

the overall safety of the slope. The effective yield area combines the nature and the regional dis-

tributionofthetensileandshearfailure.Theinfluenceofthefreezingtemperature，theheightof slope, the numbers of freeze-thaw cycles, the thermal expansion coefficient and porosity on local efectiveyiedareadecreasesinturn.Amongthem，theheightofsope，thefreezingtemperature

and the numbers of freeze-thaw cycles result mainly in the inside damage accumulation of the slope.Theangleofslope smorelkelytoleadtothesurfacefalureoftheslope，whlethether-

mal expansion coefficient and porosity will increase the damage zone and failure zone.Key words: local stability； yield approach index； slope of open-pit coal mine； permafrost regions多年冻土和季节冻土区的面积约占地球陆地面

域占国土面积的70%以上工。青海木里煤矿就处在青藏高原高寒带山地的多年冻土区，是青海省最积的50%，我国永久性冻土和季节性冻土的分布区

收稿日期：2018-03-31基金项目：国家自然科学基金资助项目(11572246,51678484)作者简介：李国锋，男，博士生，研究方向为岩土工程数值仿真分析与冻土工程。E-mail： lguofeng205@126.com通讯作者：李宁，男，教授，博导，研究方向为岩土工程数值仿真分析、寒区冻土力学与工程。E-mail：ningli@xaut. edu. cn