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1.
高地应力巷道断面形状优化数值模拟研究   总被引:7,自引:2,他引:5  
选取矩形、直墙半圆拱形、马蹄形、三心拱形、圆形和椭圆形6种巷道断面形状开展优化研究.采用FLAC5.0数值模拟软件研究了几种典型断面在岩体中开挖后巷道围岩塑性区分布、围岩主应力差分布和围岩变形特征,分析了不同侧压系数λ对它们的影响,在此基础上提出了巷道支护"等效开挖"的理念和"无效加固区"的概念.断面形状对高地应力巷道围岩主应力差分布影响不大,但等效开挖半径决定围岩塑性区分布,无效加固区越大,在巷道周边产生变形就越大,反之亦然.高应力巷道应根据λ的大小和主应力方向选择合理断面形状是圆形或椭圆形.  相似文献   

2.
分析了不同岩性围岩表面位移、围岩松动圈及塑性圈半径随巷道埋置深度即原岩应力变化,结果表明:围岩表面位移随巷道埋深即原岩应力加速增加,围岩松动圈及塑性圈范围随巷道埋深近似线性增长。围岩岩性越差,围岩表面位移随原岩应力增长速度增加越快,而松动圈及塑性圈范围随巷道埋深即原岩应力增长有趋于稳定的趋势。  相似文献   

3.
针对某深部软岩巷道支护困难问题,首先对围岩进行力学性能试验,然后利用有限元分析方法,在基于不同埋深软岩巷道围岩变形特征研究的基础上,从巷道开挖和围岩支护两方面对深部高地应力软岩巷道围岩变形与控制进行深入研究.结果表明:随软岩巷道埋深增大,巷道围岩变形呈线性增大趋势;在深部高地应力下掘进巷道时,全断面开挖法围岩变形最大,台阶法次之,CD法最小;支护时采用柔性与刚性联合支护,围岩变形最小.联合支护技术能充分释放软岩巷道围岩变形能,发挥围岩自承能力并与支护体系共同作用,可以有效控制深部软岩巷道围岩变形,从而保证深部软岩巷道围岩的稳定性.  相似文献   

4.
本文采用数值模拟方法比较分析了有无锚杆作用下深部开采圆形和矩形巷道围岩应力、应变及变形随距巷道表面距离变化的不同特点。结果表明:锚杆随距巷道表面一定范围围岩应力、应变及变形减小,围岩应力、应变及变形随距巷道表面距离增加而衰减速度变缓;距巷道表面较远处围岩应力反而增加。锚杆作用下围岩整体移动趋势增加并将近处围岩较大应力传递到远处。  相似文献   

5.
为得出直墙拱形巷道围岩应力分布规律,应用复变函数弹性理论推导了直墙拱形巷道围岩应力分布的解析表达式。对直墙拱形巷道边界的围岩应力和巷道水平线方向的围岩应力分布规律进行分析,并考虑直墙拱形巷道断面高宽比和侧压系数对其影响规律。研究表明:在不同巷道断面高宽比、侧压系数下,直墙拱形巷道围岩应力集中区域主要集中在直墙底部底角处、拱形顶板中点附近和底板中部3个位置。不同巷道断面高宽比下,直墙拱形巷道沿水平线的应力分布规律基本相同。侧压系数大于1时,采用巷道断面高宽比小于1较有利于巷道稳定;侧压系数小于等于1时,采用巷道断面高宽比大于1较有利于巷道稳定。  相似文献   

6.
深井巷道围岩应力及变形规律的数值分析   总被引:4,自引:0,他引:4  
采用非线性有限元法,对深井巷道围岩应力及变形状态进行了数值计算.分析了巷道埋深、围岩性质和断面形状对围岩变形的影响.结果表明:当巷道埋探小于某一临界深度时,巷道周边围岩移近量随巷道埋深增加呈线性增加;当超过临界深度时,巷道围岩移近量呈现指数规律增加趋势.围岩变形破坏的临界深度取决于围岩的力学性质及巷道断面形状等因素.  相似文献   

7.
以弹塑性力学中的圆孔应力解和塑性力学的偏应力理论为基础,利用莫尔-库仑强度准则,研究了围岩偏应力场和塑性区分布规律,得到了非均匀应力场下圆形巷道围岩偏应力的计算式和塑性区半径计算方法.结果表明:巷道埋深、极坐标r、极坐标θ和侧压系数与最大和最小主偏应力的大小曲线分别呈线性分布、"八"字型分布、"笔尖"型和"X"型分布;侧压系数小于、等于和大于1.0时,会出现不同形态的蝶形塑性区;随着侧压系数的增大,塑性区边界各位置的最大主偏应力会逐渐增大,而最小主偏应力却逐渐减小,两者之间的差值越来越大;内摩擦角、内聚力和圆形巷道半径的增加,都会导致塑性区半径的减小.  相似文献   

8.
骑跨采动压巷道围岩稳定性数值模拟   总被引:3,自引:0,他引:3  
针对巷道围岩遇水膨胀软化、岩石流变特性显著及长期受采动支撑压力作用的特点,应用FLAC数值软件分析骑跨采动压巷道在不同垂距及水平距离下巷道围岩的稳定性,并研究巷道围岩应力场、变形场及塑性区的变化特征.研究结果表明:巷道围岩变形表现为以底鼓变形最大,两帮变形次之,顶板变形量相对较小的特点;受支撑压力的影响,巷道围岩的应力、变形及塑性区分布呈现明显的不对称性;随着垂距及水平距离的增加,巷道围岩应力及变形呈现出不同程度的减小趋势.  相似文献   

9.
目前对深部巷道围岩表面变形理论计算公式仅限于截面为圆形的巷道,但在工程实例中多采用矩形巷道.就目前常见的深部开采条件,采用面积等效原理进行理论分析和数值模拟分析,即将矩形巷道采用等面积原理等效于相应的圆形巷道来计算围岩表面的变形.考虑不同截面尺寸,不同巷道埋深及不同岩性这3个因素,分别选取5个水平,进行正交试验设计出25组不同开采条件下巷道围岩表面变形.初步设计出各开采条件下的最佳支护方案,并在此基础上确定淮北袁店二矿101运输巷道控制围岩稳定的合理锚杆支护参数.  相似文献   

10.
对轴对称荷载作用圆巷围岩理想弹塑性分析解——Kastner解适用于软岩和小变形情况,若用于非软岩和大变形情况,从Kastner方程会导得:不论巷道围岩塑性变形多大,巷道周边切应力恒等于岩体峰值强度;围岩所承受的地应力可以随围岩塑性区半径增大而持续增大,随巷道周边位移增大而持续增大;此外,Kastner解中切应力分布曲线在围岩弹、塑性区交界处有尖峰向上的应力集中.采用符合岩石实际的弹性、非线性硬化和软化光滑连接的应力-应变关系得到的巷道围岩分析解,可以弥补以上三点不足,恰当地反映巷道临界深度和巷道围岩自承地应力极限问题;所绘出的切应力分布曲线在围岩弹、塑性区交界处光滑连接,因而有更广的适用性和精确性,对巷、隧道围岩大变形支护设计有参考作用.  相似文献   

11.
In order to study the rules of distribution in a plastic zone of rocks, surrounding a roadway, affected by tectonic stress, we first analyzed the mechanics of a roadway affected by tectonic stress and derived a theoretical formula for the plastic zone of rocks surrounding a roadway. We also analyzed the distribution characteristics of the plastic zone under different levels of tectonic stress, vertical pressure, cohesion and friction angle of the surrounding rock. Secondly, we used numerical simulation to analyze the range and shape features of the plastic zone of rocks surrounding the roadway, given different tectonic stress levels. Finally we used a rock drilling detector to carry out field measurements on the broken state of rock surrounding the roadway at the -700 substation and channels in the Xinzhuang mine of the Shenhuo mining area. Given the measured ground stress, we analyzed the relationship between tectonic stress and the distribution of this plastic zone. Our results show that the range of the plastic zone at the top and bottom of the roadway increases with an increase in tectonic stress and this increase is especially obvious at the roadway comer.  相似文献   

12.
For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, I-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.  相似文献   

13.
软岩巷道支护荷载的确定方法   总被引:5,自引:0,他引:5  
通过分析巷道围岩与支护的相互作用原理 ,得出了软岩巷道失稳的原因是由于围岩自承力与支护力不足的结果 .认为一个优化的软岩巷道支护设计应在确保支护稳定的前提下 ,最大限度地释放围岩的能量 ,使以变形形式转化的工程力达到最大 ,同时最大限度地发挥围岩的自承能力 ,使工程支护力达到最小 ,而其关键是确定变形能释放时间和最佳支护时间 .软岩巷道开挖后 ,通常在巷道周围形成塑性软化区和塑性流动区 ,实施支护力就是要控制塑性流动区的范围与发展 ,达到最佳支护时间时的支护荷载为最小支护荷载 ,可以通过塑性软化区和塑性流动区内岩石的重力求得  相似文献   

14.
Based on the safety coefficient method,which assigns rock failure criteria to calculate the rock mass unit,the safety coefficient contour of surrounding rock is plotted to judge the distribution form of the fractured zone in the roadway.This will provide the basis numerical simulation to calculate the surrounding rock fractured zone in a roadway.Using the single factor and multi-factor orthogonal test method,the evolution law of roadway surrounding rock displacements,plastic zone and stress distribution under different conditions is studied.It reveals the roadway surrounding rock burst evolution process,and obtains five kinds of failure modes in deep soft rock roadway.Using the fuzzy mathematics clustering analysis method,the deep soft surrounding rock failure model in Zhujixi mine can be classified and patterns recognized.Compared to the identification results and the results detected by geological radar of surrounding rock loose circle,the reliability of the results of the pattern recognition is verified and lays the foundations for the support design of deep soft rock roadways.  相似文献   

15.
为分析深部软岩巷道锚喷支护合理喷层厚度,以淮南矿区具有典型特征某深部采区软岩巷道为例,采用FLAC3D软件,建立了合理应变软化数值计算模型,基于数值模拟方法分析不同喷层厚度围岩塑性范围及位移场分布,在此基础上进一步分析不同巷道埋深喷层厚度对围岩松动破碎影响。结果表明:深部巷道喷层对围岩塑性圈范围及松动破碎都有显著控制作用。针对淮南矿区典型深部巷道,合理喷层厚度应为200 mm。  相似文献   

16.
In the non-uniform stress field, the surrounding rock plastic zone of the circular roadway shows different shapes under the different confining pressure conditions. Based on the boundary shape characteristics of the plastic zone, the characteristic radii of the plastic zone were proposed, namely the horizontal,longitudinal and medial axis radii, which could reflect the plastic zone shapes characteristics and classify the sizes of the key parts. On the theoretical basis of elastic-plastic mechanics, analytical solutions for the characteristic radii were obtained by theoretical deduction, and the relationships between the characteristic radii and key influencing factors were analyzed. Finally, the evaluation criterion of the circular roadway surrounding rock plastic zone shapes, evaluation criterion of the location of potential hazards caused by the roadway surrounding rock and evaluation critical points of roadway dynamic disasters based on characteristic radii were proposed. This work could provide a theoretical basis for stability analysis of the surrounding rock, support design, and guide the prevention and control of dynamic roadway disasters.  相似文献   

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