龙游石窟砂岩在不同含水状态下的弹性波速与力学性能

 为研究水环境变化对龙游石窟风化破坏的影响，进行不同含水状态下砂岩的力学性能和弹性波测试，分析在不同含水条件下砂岩的应力–应变曲线、峰值强度和弹性模量的变化规律。分析结果表明：含水率对岩石的应力–应变曲线、峰值强度和弹性模量等力学性质有显著影响，随着含水率的增加，应变软化特性弱化，峰值强度和弹性模量呈指数减少。弹性波速的测试结果表明，单轴抗压强度与波速具有线性关系；含水率为1.5％时，弹性波速出现反常，降低到一个很低的值，主要原因是砂岩中含有较多膨胀性的黏土矿物；各向异性受含水率的影响并不明显；干燥、稳定的环境有利于洞室的保护。

ELASTIC WAVE VELOCITY AND MECHANICAL PROPERTIES OF SANDSTONE UNDER DIFFERENT WATER CONTENTS AT LONGYOU GROTTOES

To study the impact of water environment change on weathering and damage of Longyou grottoes，the experimental research on the mechanical property and the elastic wave velocity of sandstone under different water contents is conducted. The change laws of stress-strain curve and mechanical properties such as peak stress，elastic modulus are also analyzed. The analysis results show that the water content has obvious effect on stress-strain curve and mechanical properties of sandstone：strain softening behavior weakens，peak stress and elastic modulus decreases exponentially with the increase in water content. Elastic wave velocity test results indicate that the uniaxial compressive strength is linear with elastic wave velocity，and the elastic wave velocity decreases abnormally to a very low value at the water content of about 1.5% due to expansible clay minerals. The water content has a little impact on anisotropy. Therefore，it can be concluded that dry and steady environment is of benefit to the conservation of Longyou grottoes.