优势裂隙倾角对反倾岩质边坡变形影响分析
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摘要
通过底摩擦实验试验在前人的基础上进一步研究优势裂隙组的倾角变化对反倾岩质边坡变形破坏影响。将反倾岩质边坡变形破坏区域分为剪切滑移区、倾倒破坏区以及倾倒变形影响区。实验试验结果及理论分析表明:①裂隙的存在使得岩体呈现非均质各向异性的特性且裂隙的倾角不同对岩体强度的折减也是不同的,当裂隙倾角θ满足关系式:θ∈[π-(α+50°),π-(α+40°)](α为岩层倾角)时,对反倾岩质边坡的整体强度折减达到最大;②当裂隙倾角θ对反倾岩质边坡的岩体强度折减达到最大时,剪切滑移区在反倾岩质边坡的破坏区域中的占比达到最大,与之呈正相关;③反倾岩质边坡发生最终破坏需要的时间主要与前缘以剪切破坏为主导的剪切滑移区的占比有关,剪切越多区的占比越大,边坡发生破坏所需时间越多,反之边坡破坏所需时间越少。
Based on the bottom friction experiment and previous researches, the effect of the dip angle of the dominant fissure set on the deformation and failure of the anti-dip rock side slope was studied. The deformation and failure zone were divided into shear slip zone, toppling failure zone and toppling deformation zone. The experimental results and theoretical analysis are:(1) the non-unit anisotropy of rock body is caused by fracture and different dip angle of the crack can result in different reduction for rock mass strength. When the dip angle satisfies the relation expression: θ∈[π-(α+50°),π-(α+40°)](α is the dip angle of rock stratum), the maximum overall strength reduction of the anti-dip rock slope shall be reached;(2) when the reduction from fracture slope angle reaches the maximum for the rock mass strength of the anti-dip rock side slope, shear slip zone also takes up the most of the failure area in the anti-dip rock side slope, where the angle and the shear slip zone proportion have a positive correlation;(3) and the time required for ultimate failure of the anti-dip rock side slopes is mainly related to the proportion of shear slip zones dominated by shear failure in the front edge. More shear means more shear slip zones, which will prolong the time for side slope failure, and vice versa.
Based on the bottom friction experiment and previous researches, the effect of the dip angle of the dominant fissure set on the deformation and failure of the anti-dip rock side slope was studied. The deformation and failure zone were divided into shear slip zone, toppling failure zone and toppling deformation zone. The experimental results and theoretical analysis are:(1) the non-unit anisotropy of rock body is caused by fracture and different dip angle of the crack can result in different reduction for rock mass strength. When the dip angle satisfies the relation expression: θ∈[π-(α+50°),π-(α+40°)](α is the dip angle of rock stratum), the maximum overall strength reduction of the anti-dip rock slope shall be reached;(2) when the reduction from fracture slope angle reaches the maximum for the rock mass strength of the anti-dip rock side slope, shear slip zone also takes up the most of the failure area in the anti-dip rock side slope, where the angle and the shear slip zone proportion have a positive correlation;(3) and the time required for ultimate failure of the anti-dip rock side slopes is mainly related to the proportion of shear slip zones dominated by shear failure in the front edge. More shear means more shear slip zones, which will prolong the time for side slope failure, and vice versa.
引文
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[10] 张年学,李守定,李晓.用岩块抗剪强度估算抗压与抗拉强度的方法[C]//第三届全国岩土与工程学术大会论文集.成都:中国地质学会, 2009.
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[2]孙广忠,张文彬.一种常见的岩体结构-板裂结构及其力学模型[J]. 地质科学, 1985, 28(3): 275-282.
[3] 蔡静森,晏鄂川,王章琼,等.反倾层状岩质边坡悬臂梁极限平衡模型研究[J].岩土力学,2014,35(S1):15-28.
[4]邢一飞,张诚,王建辉.西南地区典型弯曲倾倒式滑坡变形演化机理及防治研究[J].科学技术与工程,2016,16(22):156-161.
[5]邱俊,吴志柏,陈涛.顺层边坡“滑移-弯曲”向倾倒变形演化探讨[J].人民珠江,2018,39(8):62-65.
[6]张以晨,佴磊,沈世伟,等.反倾层状岩质边坡倾倒破坏力学模型[J].吉林大学学报(地球学版), 2011, 56(S1): 207-213.
[7]王东,刘长武,王丁,等.复杂应力条件下岩石的拉剪变形及破坏准则研究[J].四川大学学报(工程科学版), 2012, 56(2): 31-35.
[8] 张志强.非贯通裂隙岩体破坏细观特征及其宏观力学参数确定方法[D].西安:西安理工大学,2009.
[9]谢良甫.基于地质几何分区的反倾边坡倾倒变形特征[J].科学技术与工程,2018,18(12):32-37.
[10] 张年学,李守定,李晓.用岩块抗剪强度估算抗压与抗拉强度的方法[C]//第三届全国岩土与工程学术大会论文集.成都:中国地质学会, 2009.
[11]赵海斌,蒋中明,伍东卫.层状岩体抗剪强度产状效应的数值试验研究[J].人民长江,2015,46(13):61-66.