摘要
隧道(洞)围岩的地应力状态是隧道(洞)前期设计所需的重要参数。为准确计算地应力,首先搭建水压致裂流固耦合模拟试验平台;之后在该试验平台对不同压裂液流量的花岗岩岩样进行三轴试验,得到相应的压裂参数;最后通过理论推导得到水平孔地应力计算模型,将模型计算结果与试验设置的地应力大小进行比较,提出修正公式用于改进该模型,进而得到考虑不同压裂液流速的水平孔水压致裂法地应力计算模型。结果表明:压裂液流量越大,裂缝扩展长度越大、宽度越小,压裂体积越大;水平孔水压致裂过程中,泵压的增长形式为非线性;压裂液流量与破裂压力峰值正相关,但达到临界值后继续增大压裂液流量反而导致破裂压力下降;修正后的地应力计算模型考虑压裂液流量,与试验结果的相对误差在9%以内。
The geostress state of the surrounding rock of a tunnel is an important parameter required for the early design of the tunnel.In or⁃der to accurately calculate the geostress,firstly,it built a hydraulic fracturing fluid structure coupling simulation test platform.Afterwards,triaxial tests were conducted on granite rock samples with different fracturing fluid flow rates on the testing platform to obtain corresponding fracturing fluid parameters.Finally,a stress calculation model for horizontal boreholes was obtained through theoretical derivation,compared the calculated results of the model with the geostress values set in this experiment,proposed a correction formula to improve the model,and obtained a horizontal hole hydraulic fracturing method geostress calculation model that considered different fracturing fluid flow rates.The re⁃sults show that the larger the flow rate of the fracturing fluid,the longer and shorter the crack propagation length and width,and the larger the fracturing volume;during the hydraulic fracturing process of a horizontal hole,the increase in pump pressure is non⁃linear;the flow rate of fracturing fluid is positively correlated with the peak fracturing pressure,but increasing the flow rate of fracturing fluid after reaching the criti⁃cal point actually leads to a decrease in fracturing pressure;the revised geostress calculation model takes into account the fracturing fluid flow rate,and the relative error with the experimental results is controlled within 9%.
作者
刘继国
程勇
舒恒
刘夏临
朴昇昊
马保松
LIU Jiguo;CHENG Yong;SHU Heng;LIU Xialin;PIAO Shenghao;MA Baosong(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China;Research and Development Center on Tunnel and Underground Space Technology,CCCC,Wuhan 430056,China;School of Civil Engineering,Sun Yat-Sen University,Guangzhou 510275,China)
出处
《人民黄河》
CAS
北大核心
2024年第12期131-136,143,共7页
Yellow River
基金
新疆维吾尔自治区科技重大专项(2020A03003-1)
中交集团重点专项(2020-ZJKJ-ZDZX01)。
关键词
地应力
水压致裂法
水平孔
修正公式
压裂液流量
geostress
hydraulic fracturing method
horizontal hole
correction formula
fracturing fluid flow rate
