【作者】 荆升国；

【导师】 谢文兵；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2009， 博士

【摘要】 在煤矿软岩巷道中,高应力破碎软岩巷道占有相当大的比例。高应力破碎软岩巷道中支护结构性失稳是导致巷道失稳、破坏的重要原因。因此,如何提高支护承载结构稳定性及其承载能力,对解决高应力破碎软岩巷道支护难题至关重要。在高应力破碎软岩巷道中,许多情况下锚网支护难以形成可靠的承载结构,而高阻可缩U型钢支架又无法适应围岩的强烈变形。此时,采用棚-索协同支护往往能够有效地控制该类巷道围岩的强烈变形。棚-索协同支护将具备高阻可缩特性的U型钢支架作为基本支护,利用其提供的较高支护阻力提高巷道浅部破碎岩体的残余强度,并将U型钢支架作为小孔径预应力锚索的高强护表构件,发挥锚索的锚固性能,在充分发挥深部稳定岩体承载能力的同时,实现对U型钢支架的合理结构补偿,提高支架的结构稳定性及其承载能力,是解决高应力破碎软岩巷道支护难题的一条有效途径。支护结构补偿的目的是针对载荷作用下支护结构自身存在的危险截面,通过在合理位置施加一定大小的结构补偿力,能够大幅度降低支护结构危险截面承受的应力,同时降低支护结构整体承受的应力,使得支护体的承载性能得以充分发挥,提高支护结构的整体稳定性及其承载能力。研究表明,小孔径预应力锚索是目前较为理想的结结构补偿体,并从发挥结构补偿体承载性能和提高支护结构整体承载能力及其稳定性角度出发,提出支护结构补偿的基本原则。在上述研究基础上,针对煤矿常用的直墙半圆拱形巷道建立结构补偿力学模型,研究基本支护体与补偿支护体之间的相互作用关系,得出了不同载荷作用下,基本支护体内力和弯曲变形的计算公式。详细研究了均布载荷、肩部对称偏载和拱顶对称偏载三种载荷作用下,支护结构合理补偿位置的确定方法,同时分析了不同载荷作用下,支护结构的内力和弯曲变形分布特征,以及结构补偿对提高支护结构稳定性和承载能力的作用。与此同时,通过数值模拟手段研究了棚-索协同支护相互作用关系和控制巷道围岩变形的作用,并进一步通过棚-索协同支护1:1相似模拟实验,对U型钢支架实际承载过程以及棚-索协同支护的相互作用过程展开详细研究。此外,基于圆形巷道的弹塑性力学模型,分析了棚-索协同支护中结构补偿锚索的合理长度及补偿时机。最后,棚-索协同支护成功应用于典型的动压影响和构造、水体影响巷道工程实践。论文有图86幅,表16个,参考文献119篇。更多还原

【Abstract】 The soft fragmentized surrounding rock roadway with high stress accounts for quite high proportion among soft roadways in coal mine. Losing stability of supporting structure is the main reason for destroy of soft fragmentized surrounding rock roadway with high stress. Improving the bearing capacity and stability of supporting structure is very important for resolving the supporting problem in those roadways.In soft fragmentized surrounding rock roadway with high stress, it is difficult to shape dependable bearing structure by bolt-mesh support. And the u-steel frame cannot fit strong deformation of surrounding rock. Here cooperating support of frame and anchor cable can effectively control surrounding rock strong deformation.In cooperating support of frame and anchor cable, the u-steel frame which has high resistance and contractible, is used as the basic support. The frame with higher supporting resistance can improving the residual strength of fragmentized surrounding rock and can also be used as high strength protection surface component of small diameter pre-stressed anchor cable, and take advantage of anchor capacity of cable. Meanwhile the u-steel frame is compensated by anchor cable set in rational location. This is effective method to solve support problem in soft fragmentized surrounding rock roadway.The purpose of structure compensation is to decrease the bend stress in dangerous section by applying some compensation force in rational location of supporting structure. At the same time, the whole bend stress in supporting structure also to be decreased. The bearing capacity of supports can be fully played. The baring capacity and stability of supporting structure is also improved. That shows the small diameter pre-stressed anchor cable is ideal compensation instrument. The basic principle of structure compensation is proposed aiming at fully take advantage of the compensation instrument bearing capability and improving the stability of supporting structure.Based on the study mentioned above, the numerical model which revel the interaction mechanism between basic support and compensation instrument, is founded for semicircle shape roadway common used. The calculation formula of internal force and bend deformation of basic support is given in different load condition. And the rational compensation location, internal force, bend deformation are analyzed in detail for uniform load, symmetric bias load in humeral and vault. The effect of improving the structure stability and bearing capacity by structure compensation is also analyzed.At the same time, the mechanism of cooperating support of frame and anchor cable is studied by numerical simulation. The real bearing process of u-steel frame and interaction process between the frame and cable are studied in detail by the 1:1 similarity simulation experiment of cooperating support of frame and anchor cable. In addition, based on the circular roadway elastic-plastic mechanical model, the rational length of anchor cable for structure compensation and compensation opportunity are derived theoretically for cooperating support of frame and anchor cable.At last, the cooperating support of frame and anchor cable technique was successfully applied in two type of roadways effected by dynamic pressure or geological pressure and water.There are 86 figures, 16 tables and 119 references更多还原