Research And Development Of Quick-setting Material For Hole Expanding And Filling And Its Influence On Anchorage Performance

In the soft rock roadway,due to the weak nature of the surrounding rock of the bolt,the anchorage system can not provide enough tensile force,and the slip failure between the anchorage agent and the surrounding rock is easy to occur,so that the whole anchorage system is destroyed or failed,and the preload effect on the surrounding rock is lost,which seriously affects the stability of the roadway and restricts the safe and efficient mining of the mining area.In order to solve the problem of low anchorage force of weak surrounding rock,a new type of quick-setting filling material was developed.On the basis of the bolt end hole expansion and anchorage,it is filled in the hole expansion site to realize the synchronous modification of the surrounding rock of the hole expansion site,improve the physical and mechanical properties of the surrounding rock of the borehole in the anchorage section,and increase the bond strength of the anchorage agent-surrounding rock interface.The pullout test and numerical simulation test show that the anchorage system with quicksetting material for hole-expanding filling is more stable.The main conclusions are as follows :(1)The anchorage agent-surrounding rock interface is the weakest part in the bolt support system,and its improvement is the key to the stability of the anchorage system.Compared with the conventional anchorage,the wedge-shaped hole expansion and the inverted wedge-shaped hole expansion,the wedge-shaped hole expansion is the best hole expansion shape.(2)A kind of quick-setting material was prepared by using double fast cement,river sand,water reducing,early strength agent and accelerator.The optimal ratio was10 % accelerator,2 % early strength agent,1:2 cement-sand ratio,and 0.2 water-solid ratio.(3)The ultimate bearing capacity of conventional anchorage is 35.34 KN.the hole expanding and filling anchorage of ordinary material is 72.11 KN,and the hole expanding and filling anchorage of quick-setting material is 96.26 KN.The anchorage effect of quick-setting material is the best.(4)ANSYS numerical simulation test results show that the stability of the anchorage system from weak to strong is conventional anchorage,the hole expanding and filling anchorage of ordinary material,the hole expanding and filling anchorage of quicksetting material.Figure 66,table 6,reference 76.