冻融作用下不同裂隙形态岩体损伤特性研究

Study on Damage Characteristics of Rock Mass with Different Cracks Morphology under Freeze-thaw Action

寒区基础建设和资源开发对社会发展意义重大。将玉龙铜矿地区的预制裂隙灰岩进行冻融循环试验和单轴压缩试验,重点探究了不同裂隙夹角、不同冻融循环次数对岩体质量、有效孔隙率、抗压强度及冻融风化程度系数的影响。研究发现:随着冻融循环次数的增加,岩体质量、抗压强度及冻融风化程度系数均出现下降,且下降速率逐渐增大,与冻融过程中有效孔隙率的增加有关,体现了次生裂隙对冻融效果的促进作用;而抗压强度随裂隙夹角的增大而增大,与岩样的最小抵抗面积有关。此外,孔隙率和高硬度会对冻融风化产生抑制作用,减缓岩体冻融劣化损伤的进程。

Infrastructure construction and resource development in cold regions are of great significance to social development.The freeze-thaw cycle test and uniaxial compression test were carried out on the prefabricated fractured limestone in the Yulong copper mine area.The effects of different fracture angles and different freeze-thaw cycles on rock mass quality,effective porosity,compressive strength and freeze-thaw weathering degree coefficient were investigated.It is found that with the increase of freeze-thaw cycles,the rock mass quality,compressive strength and freeze-thaw weathering degree coefficient all decrease,and the decrease rate gradually increases,which is related to the increase of effective porosity during freeze-thaw process,reflecting the promoting effect of secondary cracks on freeze-thaw effect.The compressive strength increases with the increase of the crack angle,which is related to the minimum resistance area of the rock sample.In addition,porosity and high hardness will inhibit freeze-thaw weathering and slow down the process of freeze-thaw deterioration damage of rock mass.