【作者】 鲁岩；

【导师】 邹喜正； 刘长友；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2008， 博士

【摘要】 构造应力是地壳构造运动在岩体中形成的应力,包括地质历史时期的残余构造应力和现今构造应力;构造应力场是具有成生联系的各种构造形迹在不同部位应力状态的总和。构造应力场以水平应力为主,最大、最小水平构造应力一般随深度呈线性变化。构造应力在煤矿开采深度范围内大小分布较为分散,但是其方向性明显,向地壳深部发展,趋向于静水压力状态。应用广义平面应变问题的理论模型,FLAC3d三维数值模拟,结合大量现场实测资料,对构造应力场中巷道布置进行了研究。研究表明巷道的稳定性与巷道布置方向关系密切,围岩破碎区范围随巷道轴向与最大构造应力方向夹角α的增大而增大,围岩应力与位移随sin 2α变化。α对巷道的稳定性影响为:在α=0～15°范围内为影响轻微区;在α=15°～75°范围内为影响增长区;在α=75°～90°范围内为影响剧烈区;α=0时对巷道的稳定最有利,α=90°时对巷道的稳定最不利。在兖州与神火矿区的实测证实构造应力方向对巷道布置的影响是明显的。应用弹塑性理论,FLAC2d数值模拟,结合现场实测对构造应力场中巷道失稳规律进行研究。研究表明构造应力对巷道围岩稳定性影响是非均称的,随水平构造应力的增加,巷道顶底部的塑性区范围逐渐增大,尤其在巷道的肩角增加更为明显;当侧压系数λ大于极限值后,巷道围岩塑性区迅速扩大,此极限值随巷道围岩强度增加而增加,随埋深增加而减小。采用真三轴巷道模拟实验对构造应力场中煤巷锚杆支护进行了模拟研究。研究表明,水平构造应力导致巷道顶底板岩层之间相互滑移并产生离层,降低岩层抗剪能力而使顶底板剪切破坏,使顶板锚杆失去支护作用,顶板岩层逐渐冒落成拱形;两帮煤体向巷道空间呈总体移动趋势,与煤层顶底板岩层间产生明显的相对位移;帮锚杆主要受拉伸作用,控制煤岩体的塑性变形;顶锚杆主要受到剪切作用,控制顶部岩层的滑移、离层,顶板岩层破坏后顶锚杆提供约束力,提高岩体的残余强度。现场实践证明了构造应力作用下巷道顶板岩层的离层滑动,导致顶板岩层与锚杆、锚索的剪切破坏。应用弹性理论,结合现场实测对构造应力场内采动巷道研究表明,在构造应力影响下,回采工作面附近采动巷道围岩存在水平、垂直拉应力区。拉应力范围随冒落带高度与周期来压步距的比值的增大而增大,随水平构造应力与垂直应力的比值的增大而增大。处于卸荷区的采动巷道表面位移显著增大,应采用卸荷岩体加固方法对围岩进行控制,以提高其稳定性。上述研究成果在现场生产实践得到检验,对高构造应力区巷道布置与围岩控制具有重要的指导意义。该论文有图89幅,表19个,参考文献147篇,其中外文文献26篇。更多还原

【Abstract】 Tectonic stress which includes residual tectonic stress of the geological history and current tectonic stress, is the stress induced by the tectonic movement of the lithosphere in rock masses. Tectonic stress field is summation of the stress state in different place which is induced by all kinds of tectonic trace with genetic relation.Tectonic stress field gives priority to the horizontal stress. The biggest and smallest horizontal stress usually vary with the depth linearly. The value of the tectonic stress which inclines to hydrostatic stress when going to the deep of the lithosphere, distributes rather dispersedly in the range of the coal mining depth, but its direction is obvious.The dissertation adopts the theoretical model of the generalized strain plane problem, numerical simulation of the FLAC3d and a great deal of local measure data to study the the roadway disposal in the tectonic stress field. The research indicates that the stability of the roadway connects nearly with the disposal direction of the roadway. Fragmentation zone range of the surrounding rock becomes larger with augmentation of the angleαbetween axes direction of the roadway and the biggest tectonic stress direction. Stress and displacement in the surrounding rock varies with sin 2α. The angleαinfluences to the stability of the roadway is as follow: the range ofα=0～15°is the little effect zone, the range ofα=15°～75°is the increasing effect zone, the range ofα=15°～75°is the great effect zone. The roadway is most stable whenα=0, while least stable whenα=90°. The measurement in Yanzhou and Shenhuo mining area approved that direction of the tectonic stress influenced obviously to the disposal of the roadway.The dissertation adopts the elastopastic theory, numerical simulation of the FLAC2d and local measure to study the the roadway stability in the tectonic stress field. The research indicates that tectonic stress non-harmoniously influences to the stability of the roadway surrounding rock. The range of plastic zone in the roof and floor of the roadway increases with the augmentation of horizontal tectonic stress, especially in the shoulder of the roadway. While The range of plastic zone in the sides of the roadway decreases with the augmentation of horizontal tectonic stress. The range of plastic zone in surrounding rock of the roadway enlarges rapidly when the lateral pressure coefficientλis bigger than the ultimate value which increases with the augmentation of surrounding rock strength, decreases with the minishment of the depth.The dissertation adopts the similarity simulation to simulate the bolt supporting coal roadway in the tectonic stress field. The results indicates that horizontal tectonic stress induces slippage and bed separation between the terranes in the roof and floor of the roadway, therefore, the anti-shearing capacity of the terrane falls to cause the terrane of the roof and floor to shear failure, which cause the roof bolt to lose supporting function, and then the roof terrane falls to arch gradually. Coal mass of the sides moves collectively to the roadway space, which cause obvious displacement between the coal seam and terrane of roof and floor. Sides bolts is mostly subjected to tensile function that control the plastic deformation of the coal or rock mass. Roof bolts is mostly subjected to shearing function that control the slippage and bed separation of the roof terrane. when the roof terrane destroys, Roof bolts offer restraining force to enhance residual strength of the rock mass. The local practice approve that the roof terrane of the roadway will slip and bed separate in the effect of the tectonic stress, which causes the shear failure of the roof terran, bolt and cable.Adopting elastic theory and local measure, the reseach of the roadway under mining influence in the tectonic stress and indicates that there is horizontal and vertical tensile stress zone in the surrounding rock of the roadway near the working face. The range of the tensile stress zone increases with the increase of the ratio between the height of the caving zone and periodic weighting step, with the increase of the ratio between the horizontal tectonic stress and vertical stress. The surface displacement of the roadway under mining influence augments remarkably, thus reinforce method of the unloading rock mass must be adopted to control the surrounding rock, in order to enhance the stability of the roadway.The upper research results which is proved in the local practice, have great significance in guiding to the roadway disposal and control of the surrounding rock in the high tectonic stress zone.There are 89 figures, 26 tables and 147 references including 26 foreign literature in the dissertation.更多还原