高温及围岩粗糙度对锚杆灌浆料抗拔强度影响的试验研究

摘要

In order to study the anchorage performance deterioration of the anchor bolt support structure of the high geothermal tunnel in dry heat environment,an experiment was designed to study the tensile strength of anchor grouting material under different temperatures and surrounding rock roughness.The surrounding rock roughness was simulated with different types of steel tubes.The specimens were cured under different temperatures.Based on the pull-out tests of the specimens,the load-displacement curve of the anchor bolt under different curing temperatures and surrounding rock roughness was obtained,and the regression analysis on the test data was performed by the SPSS software.Results showed that the pullout strength of the anchor was affected by the curing temperature to a certain extent.With the curing temperature lower than 35 ℃,the pullout strength of the anchor increased with the increase of temperature.With the curing temperature higher than 50 ℃,the pullout strength of anchor decreased with the increase of temperature.For bolt specimens with no thread,the bond strength of the interface between the anchor bars and grouting material was greater than that of the interface between the steel tubes and grouting material.In addition,the anchor pullout strength was much affected by surrounding rock roughness.The greater the surrounding rock roughness,the higher the pullout strength of the anchor bolt,the better the anchoring effect.%为研究高地温隧道干热环境中锚杆支护结构锚固性能劣化问题,设计不同温度及围岩粗糙度下锚杆灌浆料抗拔强度试验.采用不同类型钢管模拟围岩粗糙度,并将试件在不同温度下养护.通过试件拉拔试验,得到不同养护温度及围岩粗糙度下锚杆的荷载-位移曲线,利用SPSS软件对试验数据进行回归分析.结果表明:锚杆养护温度对其抗拔强度有一定影响,养护温度低于35℃时,锚杆的抗拔强度随温度升高而增大,养护温度高于50℃时,锚杆的抗拔强度随温度升高而减小;对于无螺纹锚杆试件,锚筋与灌浆料界面的黏结强度大于钢管与灌浆界面;围岩粗糙度对锚杆的抗拔强度有较大影响,围岩粗糙度越大,锚杆的抗拔强度越大,锚固效果越好.