基于支护预应力场的松软围岩锚杆支护护表构件优选

针对石窟煤业松软围岩锚杆支护效果差的问题，采用实验室仿真试验对钢筋托梁、W钢护板2种护表构件的支护预应力场进行监测，得出各护表构件在支护围岩各区域的应力分布差异。试验结果显示，锚杆支护预应力场沿杆体由上至下形成“拉—压—压”的应力集中区分布格局，因表面接触方式不同，2种构件支护预应力场主要在围岩浅部压应力作用区域产生差异；在100 kN预紧力下，钢筋托梁、W钢护板的支护预应力在围岩表面峰值分别为0.8、0.6 MPa，W钢护板产生的0.15、0.05 MPa压应力区域面积较钢筋托梁分别增加41.67%、21.69%。W钢护板支护预应力在围岩表面分布更为平均，预应力整体扩散范围更高，可有效适应于松软围岩。将试验结论在现场进行了工业性试验，获得了较好的支护效果。

Optimization of bolting surface components in soft surrounding rock based on supporting prestress field

In view of the poor effect of rock bolt support in the soft surrounding rock of the grotto coal industry,the laboratory simulation test is used to monitor the support prestress field of two kinds of surface protection components,namely,steel joist and W steel fender,and the stress distribution difference of each surface protection component in each area of the supporting surrounding rock is obtained.The test results show that the distribution pattern of "tension compression compression" stress concentration area is formed along the rod body from top to bottom in the prestressed field of bolt support.Due to different surface contact modes,the prestressed field of the two types of component support is mainly different in the shallow compressive stress area of surrounding rock.Under 100 kN preload,the peak values of support prestress of reinforcement joist and W steel fender on the surrounding rock surface are 0.8 MPa and 0.6 MPa respectively.The area of 0.15 MPa and 0.05 MPa compressive stress produced by W steel fender is 41.67% and 21.69% higher than that of reinforcement joist respectively.W steel support prestress is more evenly distributed on the surface of surrounding rock,and the overall diffusion range of prestress is higher,which can effectively adapt to soft surrounding rock.The results of the test have been tested in the field,and a good supporting effect has been obtained.