岩土力学2024，Vol.45Issue(7)：1906-1916,2049,12.DOI:10.16285/j.rsm.2023.1242
干湿循环脆性岩石直接拉伸断裂的宏细观力学模型
A micro-macro mechanical model of direct tensile fracture in brittle rocks under dry-wet cycles
摘要
Abstract
Aiming at the engineering problem of rock damage and failure caused by long-term dry-wet cycle conditions such as the hydro-fluctuation belt in the Three Gorges reservoir area,this paper investigates the challenging issue of the micro-macro mechanical properties of brittle rocks under the combined effects of dry-wet cycles and direct tensile loading.However,due to the challenges in conducting direct tensile tests under dry-wet cycles,there is a scarcity of macro-micro mechanical models that account for both dry-wet cycles and direct tensile loading.Based on the coupled method of the theory of fracture mechanics and the experiment of dry-wet cycle,a macro-micro mechanical model of direct tensile fracture of brittle rock under the influence of dry-wet cycle conditions is proposed.The model is developed by considering the combined effects of the number of dry-wet cycles(n)and water content(ω)on fracture toughness(KIC)and initial damage(D0).It is then integrated with a direct tensile microcrack propagation mechanical model that considers initial microcrack damage and crack fracture toughness in rocks.The theoretical results for tensile strength,wing crack limit length llim,elastic modulus,and rock deterioration damage are compared with experimental data to validate the reasonableness of the model.The influence of initial crack angle φ,material constant β,and other parameters on the variation of crack initiation stress and peak stress with the number of dry-wet cycles n is discussed.Furthermore,a comparative analysis is conducted to investigate the effects of dry-wet cycles and single water content conditions on the deterioration degree of rocks.关键词
脆性岩石/干湿循环/直接拉伸/断裂/宏细观力学模型Key words
brittle rocks/dry-wet cycles/direct tensile fracture/micro-macro model分类
建筑与水利引用本文复制引用
李晓照,车行,李海峰,戚承志..干湿循环脆性岩石直接拉伸断裂的宏细观力学模型[J].岩土力学,2024,45(7):1906-1916,2049,12.基金项目
国家自然科学基金(No.51708016 （）
No.12172036) （）
北京市教委科研项目(No.KM202110016014) （No.KM202110016014）
北京建筑大学金字塔人才工程(No.JDYC20200307).This work was supported by the National Natural Science Foundation of China(51708016,12172036),the Scientific Research Program of Beijing Municipal Education Commission(KM202110016014)and the Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture(JDYC20200307). （No.JDYC20200307）
