高地应力破碎围岩巷道变形破坏特征及支护方式研究

With the rapid economic development，the status of mineral resources in the national economy and the demand for mineral resources has been increasing.In the mining production of these resources，it is an important task to ensure enduring and effective supports，which directly affect the safe production and sustainable development of the mine.Controlling roadway deformation by using appropriate support measures has become a critically important area of focus in the study of rock mechanics and mining.Because the rocks have experienced complex high stresses for a long period of time，the physical and mechanical properties of deep rock masses can change dramatically and the deformation failure modes are significantly different from those in shallow environments.Severe deformations and failures may occur due to high ground stress a short time after roadway excavations，and these may incur large repair costs that seriously hinder the baseline economic development of a mining area.The Jinchuan Mine，the largest nickel production base in China，is located in Jinchang City，Gansu Province.It is a large and complex deposit with high ground stress，a deeply buried ore body，and broken rocks.Due to its extremely complex regional geological background，special engineering geological environment，and distinctive rock mechanics，the Jinchuan Mine has attracted the attention of researchers and experts at home and abroad.Based on the special geological conditions of high-stress and fractured surrounding rock in Jinchuan No.2 mining area，field investigations and numerical simulations were carried out to study the deformation failure characteristics of the roadway in the study area and the effects of 8 different support methods.The results show that：（1）The deformation failure types of roadway in the study area can be divided into six types，including unsymmetrical pressure，roof falling，side cracking，floor heaving，side cracking and rib spalling which is the most common one；（2）The main features of the roadway deformation include large deformation，prominent time effect and the maximum principal stress plays a dominate role.（3）Adding U-shape steel，supplementing bottom support，increasing the length of the bolts，and reducing the distance between the bolts all can improve the support effect to different degrees.The effects of supplementing U-shape steel and bottom bolt-mesh-anchor support are the most significant，which can reduce the roadway deformation and plastic zone by about 70%.Increasing bolt length can control the deformation and overall stability of the roadway better，but the optimization effect is not significant.Reducing the spacing between bolts is beneficial to control the deformation and plastic zone on each part of the roadway.The dense arrangement of bolts can effectively improve the integrity of surrounding rock，and the supporting effect is better after reducing the row spacing of bolts.The aim of the research is providing a reference for other engineering solutions under similar geological conditions.

Keywords： high geo-stress ; broken rock mass ; FLAC3D ; field investigation ; roadway deformation failure ; support methods ; Jinchuan mine