徐荣超,阎震,周文朋,等. 饱水作用对白砂岩抗拉强度及声发射特性影响的试验研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2023120016.

XU R C, YAN Z, ZHOU W P, et al．Experimental study on the influence of saturation effect on the tensile strength and acoustic emission characteristics of white sandstone [J].Journal of Henan Polytechnic University( Natural Science) ，doi:10.16186/j.cnki.1673-9787.2023120016.

饱水作用对白砂岩抗拉强度及声发射特性影响的试验研究(网络首发)

徐荣超¹，阎震¹，周文朋²，胡玉波¹，王怡博¹，高粱¹

华北水利水电大学 地球科学与工程学院，河南 郑州 450046; 2. 中国水利水电第十一工程局有限公司，河南 郑州 450001

摘要: 目的 为了研究饱水作用对砂岩的力学损伤，方法 本研究通过巴西劈裂和声发射实时监测试验,从宏观角度分析饱水作用对白砂岩的抗拉强度、声发射特性及劈裂节理面形貌的影响机制。结果 研究结果表明:(1)饱水作用导致白砂岩内部的矿物颗粒溶解，颗粒间的黏聚力下降，引起砂岩力学损伤，抗拉强度下降了11.3%;(2)受饱水作用的影响，白砂岩变形、抗拉强度的降低导致其加载过程单位面积劈裂能量显著下降;(3)在饱水作用后,砂岩声发射计数、累计能量在前期活动中减弱,且声发射计数、累计能量峰值均晚于荷载峰值出现;(4)基于声发射RA-AF的破裂类型分析表明,饱水后白砂岩的拉伸破裂占比减小,剪切破裂占比提升，两种状态的白砂岩试样在接近峰值荷载时，剪切破裂数量均出现明显增长;(5)饱水后,声发射b值降低,白砂岩劈裂过程中小尺度破裂占比下降,大尺度破裂占比提升，同时在岩石劈裂加载时声发射实时b值的陡降可以作为试样破坏的前兆特征;(6)受饱水作用的影响，白砂岩劈裂节理面的粗糙度指标：坡度均方根、粗糙度轮廓指数、劈裂节理面实际面积和粗粗糙度系数均出现下降。结论 饱水作用后白砂岩抗拉强度下降显著，大尺度破裂占比提升，劈裂节理面的粗糙度降低。

关键词: 饱水作用；砂岩；抗拉强度；声发射；节理面形貌

doi:10.16186/j.cnki.1673-9787. 2023120016

基金项目: 国家自然科学基金项目(51709113)

收稿日期：2023-12-07

修回日期：2024-04-30

网络首发日期：2024-11-19

Experimental study on the influence of saturation effect on the tensile strength and acoustic emission characteristics of white sandstone

XU Rongchao¹, YAN Zhen ¹, ZHOU Wenpeng ², HU Yubo ¹, WANG Yibo ¹, GAO Liang ¹

1. College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450046, China; 2. Sinohydro Bureau 11 Co., Ltd, Zhengzhou, Henan 450001, China

Abstract: Objectives To investigate the mechanical damage of sandstone under saturation, Methods this study conducted real-time monitoring tests using Brazilian splitting and acoustic emission techniques. The research analyzed the influence mechanism of saturation on the tensile strength, acoustic emission characteristics, and the morphology of split surfaces of sandstone from a macroscopic perspective. Results The research results indicate that: (1) Saturation leads to the dissolution of mineral particles within the white sandstone, reducing the cohesion between particles, resulting in mechanical damage to the sandstone and a decrease in tensile strength by 11.3%; (2) The deformation of white sandstone and the decrease in tensile strength due to saturation result in a significant decrease in the unit area of splitting energy during the loading process; (3) After saturation, the acoustic emission count and cumulative energy of the sandstone weaken during the initial activity, and the peak values of acoustic emission count and cumulative energy occur later than the peak load; (4) Based on the analysis of fracture types using acoustic emission RA-AF, the proportion of tensile fractures in white sandstone decreases after saturation, while the proportion of shear fractures increases. In both states of white sandstone samples, shear fractures show a significant increase in quantity near the peak load; (5) After saturation, the b value of acoustic emission decreases, the proportion of small-scale fractures during the splitting process of white sandstone decreases, and the proportion of large-scale fractures increases. Meanwhile, the sharp decrease in real-time b values during rock splitting loading can serve as a precursor feature of sample failure; (6) Under the influence of saturation, roughness indicators of splitting joint surfaces of white sandstone, including root mean square slope, roughness profile index, actual area of splitting joint surface, and roughness coefficient, all decrease. Conclusions After saturation, the tensile strength of white sandstone decreases significantly, the proportion of large-scale fractures increases, and the roughness of the splitting joint surface decreases.

Key words: water saturation; sandstone; tensile strength; acoustic emission; morphology of joint surface