锚固力作用下的边坡临界滑动场法研究与应用
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摘要
极限平衡方法计算锚固力作用下边坡稳定性时,通常将锚固力作为集中力处理,得到的滑面正应力和条间力分布曲线极不合理。除此之外,若按常规方法处理锚固力的作用,采用临界滑动场法分析锚固边坡稳定性时,搜索的滑动面会产生突变。为克服以上固有缺点,将半无限体受法向力作用的弹性力学解答近似作为锚固力在边坡体内产生的附加应力等效模型,并在此基础上建立了锚固力作用下的边坡临界滑动场计算方法,且通过算例分析表明了这种集中力近似等效处理方式的合理性,进一步丰富了锚固边坡稳定性分析方法。算例分析与工程应用表明,锚固力的作用会改变边坡临界滑动面位置,该方法能够搜索到锚固力作用下的合理临界滑动面,且滑面正应力和条间力分布曲线也较合理,相应的安全系数也较可靠。同时,该法能够全面评价边坡的整体和局部稳定性,可为实际边坡工程提供欠稳定区域的空间分布情况,使其得到有效的治理。
When calculating slope stability under anchorage force by limit equilibrium method, anchorage force is usually treated as a concentrated force, and the distribution curves of normal stress on slip surface and inter-slice forces are very unreasonable. In addition, if the effect of anchorage force is treated by conventional method and the stability of anchored slope is analyzed by critical sliding field method, the sliding surface searched will change abruptly. In order to overcome the above inherent defects, the elastic solution of semi-infinite body subjected to normal force is approximated as the equivalent model of additional stress generated by anchoring force in slope body. On this basis, the calculation method of critical sliding field of slope under anchoring force is established. The analysis of examples shows that the approximate equivalent treatment method of concentrated force is reasonable, which further enriches the stability analysis method of anchored slope. The method has also successfully applied to evaluate the stability of a practical complex slope engineering. The results show that the anchorage force can change the location of the potential slip surface. The proposed approach can search the real potential slip surface with reasonable distribution of normal stresses and inter-slice forces under the action of anchorage force and the corresponding safety factor is more reliable. Meanwhile, the method can comprehensively evaluate the overall and local stability of the slope, and provide the spatial distribution of the unstable region for the actual slope engineering, so as to effectively control it.
When calculating slope stability under anchorage force by limit equilibrium method, anchorage force is usually treated as a concentrated force, and the distribution curves of normal stress on slip surface and inter-slice forces are very unreasonable. In addition, if the effect of anchorage force is treated by conventional method and the stability of anchored slope is analyzed by critical sliding field method, the sliding surface searched will change abruptly. In order to overcome the above inherent defects, the elastic solution of semi-infinite body subjected to normal force is approximated as the equivalent model of additional stress generated by anchoring force in slope body. On this basis, the calculation method of critical sliding field of slope under anchoring force is established. The analysis of examples shows that the approximate equivalent treatment method of concentrated force is reasonable, which further enriches the stability analysis method of anchored slope. The method has also successfully applied to evaluate the stability of a practical complex slope engineering. The results show that the anchorage force can change the location of the potential slip surface. The proposed approach can search the real potential slip surface with reasonable distribution of normal stresses and inter-slice forces under the action of anchorage force and the corresponding safety factor is more reliable. Meanwhile, the method can comprehensively evaluate the overall and local stability of the slope, and provide the spatial distribution of the unstable region for the actual slope engineering, so as to effectively control it.
引文
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[2]张玉芳,袁坤.双锚固段新型锚索锚固性能研究及工程应用[J].岩土力学,2018,39(增刊1):461-468.ZHANG Yu-fang,YUAN Kun.Experimental study and application of anchor performance of a new type anchor cable with double anchor[J].Rock and Soil Mechanics,2018,39(Suppl.1):461-468.
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[11]ZHU D Y,LEE C F,QIAN Q H.Evaluation of the stability of anchor-reinforced slopes[J].Canadian Geotechnical Journal,2005,42(5):1342-1349.
[12]王邓峮,朱彦鹏.附加应力法在预应力锚杆支护结构稳定性分析中的应用[J].工程力学,2014,31(4):196-201.WANG Deng-qun,ZHU Yan-peng.Additional stress apply to analyzing the stability of prestressed anchor support[J].Engineering Mechanics,2014,31(4):196-201.
[13]朱大勇.边坡临界滑动场及其数值模拟[J].岩土工程学报,1997,19(1):65-71.ZHU Da-yong.Critical slip field of slope and its numerical simulation[J].Chinese Journal of Geotechnical Engineering,1997,19(1):63-69.
[14]朱大勇,周早生.边坡全局临界滑动场(GCSF)理论及工程应用[J].土木工程学报,1999,32(3):66-72.ZHU Da-yong,ZHOU Zao-sheng.Theory of globally critical slip field of slopes and its application to practical engineering[J].China Civil Engineering Journal,1999,32(3):66-72.
[15]杨伯源,张义同.工程弹塑性力学[M].北京:机械工业出版社,2003.YANG Bo-yuan,ZHANG Yi-tong.Engineering elastoplasticity[M].Beijing:China Machine Press,2003.
[16]徐芝纶.弹性力学[M].北京:高等教育出版社,2006.XU Zhi-lun.Elasticity[M].Beijing:Higher Education Press,2006.
[17]朱大勇,李焯芬,黄茂松,等.对3种著名边坡稳定性计算方法的改进[J].岩石力学与工程学报,2005,24(2):183-194.ZHU Da-yong,LI Zhuo-fen,HUANG Mao-song,et al.Modifications to three well-known methods of slope stability analysis[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(2):183-194.
[18]中国第二公路勘察设计研究院有限公司.JTG D30-2015公路路基设计规范[S].北京:中国建筑工业出版社,2015.China Communications Second Highway Survey and Design Institute Co.Ltd.JTG D30-2015 Specifications for design of highway subgrades[S].Beijing:China Architecture and Building Press,2003.
[2]张玉芳,袁坤.双锚固段新型锚索锚固性能研究及工程应用[J].岩土力学,2018,39(增刊1):461-468.ZHANG Yu-fang,YUAN Kun.Experimental study and application of anchor performance of a new type anchor cable with double anchor[J].Rock and Soil Mechanics,2018,39(Suppl.1):461-468.
[3]韦立德,叶志华,陈从新,等.一种锚杆计算模型及其在岩坡锚杆支护中的应用[J].岩土工程学报,2008,30(5):732-738.WEI Li-de,YE Zhi-hua,CHEN Cong-xin,et al.Effective calculation method of bolts and its application in rock slopes anchored by bolts[J].Chinese Journal of Geotechnical Engineering,2008,30(5):732-738.
[4]郝建斌,门玉明,汪班桥.地面荷载下土层锚杆工作性能试验研究[J].岩土工程学报,2009,31(2):247-249.HAO Jian-bin,MEN Yu-ming,WANG Ban-qiao.Working property of soils anchors under loads on ground surface[J].Chinese Journal of Geotechnical Engineering,2009,31(2):247-249.
[5]韩爱民,李建国,肖军华,等.预应力锚杆框架梁的支护力学行为研究[J].岩土力学,2010,31(9):2894-2900.HAN Ai-min,LI Jian-guo,XIAO Jun-hua,et al.Mechanical behaviors of frame beam supporting structure with prestressed anchors[J].Rock and Soil Mechanics,2010,31(9):2894-2900.
[6]刘华丽,李宏伟,朱大勇.锚固力在边坡加固中的工程应用[J].岩土力学,2015,36(2):509-514.LIU Hua-li,LI Hong-wei,ZHU Da-yong.A method for calculation of anchor force in slope reinforcement[J].Rock and Soil Mechanics,2015,36(2):509-514.
[7]KRAHN J.The 2001 R.M.Hardy lecture:the limits of limit equilibrium analyses[J].Canadian Geotechnical Journal,2003,40(3):643-660.
[8]张发明,赵维炳,刘宁.预应力锚索锚固荷载的变化规律及预测模型[J].岩石力学与工程学报,2004,23(1):39-43.ZHANG Fa-ming,ZHAO Wei-bing,LIU Ning.Long-term performance and load prediction model of prestressed cables[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(1):39-43.
[9]程良奎,范景伦,韩军,等.岩土锚固[M].北京:中国建筑工业出版社,2003.CHENG Liang-kui,FAN Jing-lun,HAN Jun,et al.Ground anchorage[M].Beijing:China Architecture and Building Press,2003.
[10]LITTLEJOHN G S.Long-term performance of high capacity rock anchors at Dovonport[J].Ground Engineering,1979,12(7):25-33.
[11]ZHU D Y,LEE C F,QIAN Q H.Evaluation of the stability of anchor-reinforced slopes[J].Canadian Geotechnical Journal,2005,42(5):1342-1349.
[12]王邓峮,朱彦鹏.附加应力法在预应力锚杆支护结构稳定性分析中的应用[J].工程力学,2014,31(4):196-201.WANG Deng-qun,ZHU Yan-peng.Additional stress apply to analyzing the stability of prestressed anchor support[J].Engineering Mechanics,2014,31(4):196-201.
[13]朱大勇.边坡临界滑动场及其数值模拟[J].岩土工程学报,1997,19(1):65-71.ZHU Da-yong.Critical slip field of slope and its numerical simulation[J].Chinese Journal of Geotechnical Engineering,1997,19(1):63-69.
[14]朱大勇,周早生.边坡全局临界滑动场(GCSF)理论及工程应用[J].土木工程学报,1999,32(3):66-72.ZHU Da-yong,ZHOU Zao-sheng.Theory of globally critical slip field of slopes and its application to practical engineering[J].China Civil Engineering Journal,1999,32(3):66-72.
[15]杨伯源,张义同.工程弹塑性力学[M].北京:机械工业出版社,2003.YANG Bo-yuan,ZHANG Yi-tong.Engineering elastoplasticity[M].Beijing:China Machine Press,2003.
[16]徐芝纶.弹性力学[M].北京:高等教育出版社,2006.XU Zhi-lun.Elasticity[M].Beijing:Higher Education Press,2006.
[17]朱大勇,李焯芬,黄茂松,等.对3种著名边坡稳定性计算方法的改进[J].岩石力学与工程学报,2005,24(2):183-194.ZHU Da-yong,LI Zhuo-fen,HUANG Mao-song,et al.Modifications to three well-known methods of slope stability analysis[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(2):183-194.
[18]中国第二公路勘察设计研究院有限公司.JTG D30-2015公路路基设计规范[S].北京:中国建筑工业出版社,2015.China Communications Second Highway Survey and Design Institute Co.Ltd.JTG D30-2015 Specifications for design of highway subgrades[S].Beijing:China Architecture and Building Press,2003.