中风化片岩地区岩石锚杆基础试验研究

Experimental Investigation of Rock Bolt Foundation in Moderately Weathered Schist Area

针对工程中典型中风化片岩地质状况,在现场进行一系列单锚和群锚原型试验,研究了单锚的临界锚固深度,分析了不同锚固长度锚杆的承载特性与破坏机制,给出了此种岩性中锚杆的锚筋与砂浆黏结强度τa、砂浆与岩石黏结强度τb、岩石等代极限剪切强度τs,对比分析了自密实混凝土2种锚杆灌浆料对砂浆与岩石黏结强度τb的影响;同时,试验研究了群锚基础的"群锚效应",通过轴力检测得出了群锚基础下各锚杆间的轴力呈碟形分布的规律。复合受载试验表明,在中风化片岩中往复水平荷载会对群锚荷载传递产生影响,但是不足于影响群锚基础的极限抗拔承载力。研究成果对典型中风化片岩地质状况的锚杆基础具有重要的工程指导意义。

This paper based on the typical moderately weathered schist geological condition in engineering, doing a series of single anchor and group anchor prototype testing in site, studying the critical depth of the single anchor, analyzing the load-bearing characteristics and failure mechanism with different anchoring length, giving the bonding strength between anchor steel and mortar a 、mortar and rock b 、rock ultimate shear strength s.Then comparing two different grouting materials,analyses their affects on mortar and rock b, at the same time, this test researches the anchor group effect,by testing,we can know the axial forces between all anchors distributing as a dish shape. The load bearing test shows that horizontal load will affects the group anchor loads transmission in moderately weathered schist,but it will not affect the ultimate bearing capacity of group anchor foundation.And all these results have an important affect on moderately weathered schist geological condition.