高地温水工高压隧洞结构模型试验研究  

Structural model tests of high-pressure hydraulic tunnels under high geotemperature conditions

作　　者：彭立锋[1] 苏国韶[1,2] 胡小川[1] 秦子华 何保煜 PENG Lifeng;SU Guoshao;HU Xiaochan;QIN Zihua;HE Baoyu(School of Civil and Architecture Engineering,Guangxi University,Nanning 530004;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education,Guangxi University,Nanning 530004)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,南宁530004

出　　处：《水力发电学报》2019年第3期203-217,共15页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(51369007,41472329)。

摘　　要：为揭示高地温梯度与高内水压力联合作用下水工隧洞围岩的承载特性,在研制完整硬岩多物理场相似材料的基础上,通过温度荷载与内水压力联合加载技术开发,结合声发射的信号监测与空间定位技术,开展大比尺高地温水工高压隧洞的水工结构模型试验,对隧洞围岩的温度场、渗压场、声发射和裂纹发育的动态演化过程进行了测试与分析。试验结果表明,与非高地温条件相比,高地温条件下水工高压隧洞围岩出现水力劈裂所需的临界内水压力明显较低;与非高地温条件下围岩出现少数几条主裂缝不同,高地温条件下围岩主裂缝之间的次生裂缝甚为发育;高地温条件下水工高压隧洞围岩的热-水-力多物理场耦合效应明显,内水压力不变条件下围岩的裂缝扩展与损伤增长呈现非连续阶跃变化特征;高地应力条件下高地温水工高压隧洞水力劈裂位置与裂缝扩展受地应力侧限系数影响较大。To reveal the bearing characteristics of surrounding rock mass of hydraulic tunnels under the combined effects of high geotemperature and high internal water pressure,this study conducts experimental tests on a large-scale structural model of a hydraulic pressure tunnel with large geotemperature gradients in multi-physical fields through developing a similar material of complete hard rock mass.For the tests,we adopt acoustic emission techniques for signal monitoring and locating,develop a new loading technique of combined temperature loads and internal water pressure,and analyze the dynamic evolution processes of temperature field,pore pressure field,acoustic emission,and fracture propagation.Results show that compared to the condition without high geotemperature,the critical internal water pressure of the surrounding rock mass of the tunnel at the start of hydraulic fracturing is lowered obviously.In a high geotemperature environment,the induced cracks between the main fractures in the rock mass have evolved quite completely,manifesting the difference from the normal geotemperature cases where only a few main fractures are mobilized.And the rock mass has undergone an obvious coupling effect of thermo-hydro-mechanical fields,and the fracture propagation and increasing damage of the rock mass are featured with discontinued step evolution under constant water pressure.Under high in-situ stress conditions,the locations of hydraulic fractures and fracture propagation are influenced significantly by the lateral confining coefficient of in-situ stress.

关 键 词：水工隧洞 结构模型试验 高地温 高水压 热-水-力耦合 

分 类 号：TV32[水利工程—水工结构工程]