摘要
选取高放射核废物处置库重要预选场区甘肃北山地区的花岗岩,制作750 mm(宽)×300 mm(厚)×1 000 mm(高)的稀疏不规则裂隙岩体模型,该模型由18块花岗岩和竖向与斜向各两条裂隙组成,在裂隙及岩石内部埋置温度传感器、水压计、直角应变花,并在模型一侧设置局部热源,研究热源温度和裂隙水流速对岩石温度和应力的影响。结果表明,竖裂隙水主要从顶部进水口流向底部出水口,斜裂隙水主要从侧部进水口流向侧部出水口,竖裂隙与斜裂隙在交汇处存在微小流量交换;由于热源处在两条斜裂隙进水口之间,并且斜裂隙长度小于竖裂隙,岩石热传导与斜裂隙水流对岩石温度分布起控制作用,竖裂隙水流对岩石横向热传导起阻滞作用;由于热传导和水流传热的不规则性,上层岩石形成从左向右为主的传热路径,中层和下层岩石形成从上向下为主的传热路径;由于上、下层岩石温度梯度较小,岩石收缩受热拉应力,而中层岩石温度梯度较大,岩石膨胀受热压应力,大主应力的方向大致垂直于斜裂隙面与竖裂隙面的交线,岩石应力增量随斜平面方向的温度梯度增大而增大;热源温度越高,裂隙水流速越低,岩石温度越高、岩石应力越大,系统达到稳态需要的时间越长。
The granites are taken from Beishan area in Gansu province which is selected as a potential high-level radioactive waste disposal repository in China. The sparsely irregularly fractured rock model of 750 mm ×300 mm ×1 000 mm（width × thickness × height） consists of 18 granite rocks with vertical and oblique fractures with thermal sensors, pressure sensors and square strain rosettes installed in the interior, and a heater is placed on one side to study the influence of the heat source temperature and the crack velocity on the temperature and stress of the rock. The test results reveal that： vertical fracture water flow is mainly from the top inlet to the bottom outlet vertically, and oblique fracture water flow is mainly from the side inlet to outlet obliquely, with weak interchange flows at the intersections of the vertical and oblique fractures. Heat conduction and oblique fracture water flow control the temperature distributions in the model because a heater is put between the two oblique fracture intakes and oblique fracture length is less than the vertical fracture, while the vertical fracture water flow hinders heat conduction to the far side of the heat source. Heat transfer paths are mainly from left to right in the upper rock layer and from top to bottom in the middle rock layer and the low rock layer, due to the irregularities of heat conduction and water flow and heat transfer. The temperature gradients are smaller and thus contraction of rock is affected by tensile stress in the upper and lower rock layers, whereas the temperature gradients are larger and expansion of rock is affected by compressive stress in the middle rock layer. The major principal stress direction is being approximately orthogonal to the intersections of the oblique fracture planes and the vertical fracture planes, and the stress increment increases with the increasing of temperature gradients in the oblique planar direction. The higher the heat source temperature is, the lower the fracture water flow velocity is, the high
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第11期3145-3155,共11页
Rock and Soil Mechanics
基金
国家科技支撑计划课题(No.2013BAB10B06)~~
关键词
稀疏不规则裂隙岩体
热源
裂隙水流速
三维水流-传热
温度应力
模型试验
sparsely irregularly fractured rocks
heat source
fracture water velocity
3D water flow and heat transfer
temperature and stress
model test
