浸水时长对岩体强度及破坏特征影响的试验研究  

Experimental study on influence of immersion times on rock strength and failure characteristics

作　　者：李育宗 高胜 沈树强 张庆贺 陈文尹 胡磊 LI Yuzong;GAO Sheng;SHEN Shuqiang;ZHANG Qinghe;CHEN Wenyin;HU Lei(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan,Anhui 232001,China;China Railway No.4 Engineering Group Co.,Ltd.,Hefei,Auhui 230023,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]中国中铁四局集团有限公司,安徽合肥230023

出　　处：《岩石力学与工程学报》2025年第1期99-113,共15页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金青年基金资助项目(42107187)。

摘　　要：深入研究与时间相关的水‐岩作用,对防控和治理工程失稳灾害具有重要意义。针对未浸水和浸水时长分别为30,90和180 d的砂岩、大理岩和花岗岩试样,开展室内单轴压缩、巴西劈裂以及直剪试验,深入探讨并揭示浸水时长对岩石的力学和破坏特征的影响机制。研究结果表明,浸水后,砂岩试样的力学强度明显下降,且随着浸水时长的增加,下降趋势逐渐减缓;大理岩和花岗岩试样的抗压强度在浸水30 d后明显下降,但在浸水90 d后出现了上升趋势,然后再次下降,抗剪强度也呈现类似的变化趋势。这3种岩石试样强度的变化可能是由于岩石内部矿物颗粒之间的胶结物发生溶蚀弱化和岩石内部饱水孔隙不排水条件下的强度局部增强叠加而引起。通过对试样能量特征分析发现,浸水后的砂岩和花岗岩试样总输入应变能和弹性应变能(储能能力)均呈现下降的趋势,而大理岩试样的变化趋势不明显。这意味着浸水后的花岗岩试样弹射剧烈程度减弱。在此基础上,提出了一个可用于评价岩体节理面脆性特征的剪切脆性指标Bs,研究发现,随着浸水时长的增加,砂岩、大理岩和花岗岩节理面试样的脆性均呈递减趋势。研究结果可为水‐岩作用下工程围岩稳定性评价提供重要参考。A thorough investigation into time-dependent water-rock interactions is of significant importance for the prevention and control of engineering instability disasters.In this study,laboratory uniaxial compression tests,Brazilian splitting tests,and direct shear tests were conducted on sandstone,marble and granite specimens with immersion times of 30,90 and 180 d,respectively,to explore and reveal the characteristics and mechanisms of the effects of different immersion times on the strength and failure characteristics of rock masses.The results show that after immersion,the mechanical strength of sandstone specimens decreases significantly,and the decreasing trend gradually slows with increasing immersion time.In contrast,the compressive strength of marble and granite specimens decreases significantly after 30 d of immersion,but shows an increasing trend after 90 d of immersion,followed by a subsequent decrease.Similar trends are observed for their shear strength.These changes may be due to the dissolution and weakening of the cement between mineral particles inside the rock,coupled with the local strengthening of strength under non-draining conditions of water-saturated pores inside the rock mass.Analysis of the energy characteristics of the specimens revealed that the total input strain energy and elastic strain energy(stored energy capacity)of sandstone and granite specimens both show a decreasing trend after immersion,while the change in marble specimens is not significant.This suggests a reduced severity of ejection failure in granite specimens after immersion.Based on these findings,a shear brittleness index(Bs)was proposed to evaluate the brittleness characteristics of rock joints.The study found that with increasing immersion time,the brittleness of sandstone,marble and granite joints all show a decreasing trend.The results of this study can provide important references for evaluating the stability of engineering rock masses under water-rock interactions.

关 键 词：岩石力学 水-岩作用 浸水时长 岩体强度 能量特征 剪切脆性指标 

分 类 号：TU45[建筑科学—岩土工程]