摘要
为解决我国西南地区富水溶蚀白云岩地层井筒水害防治难题,采用现场注浆试验结合数值模拟研究了白云岩含水层中浆液扩散特征。现场注浆试验表明老虎洞磷矿巨厚白云岩含水层整体可注,且上段地层可注性明显好于下段。通过压水试验、钻孔取芯和COMSOL Multiphysics模拟软件,确定了老虎洞磷矿富水溶蚀白云岩含水层井筒预注浆合理孔间距为4.5 m,为后续井筒地面预注浆工程设计提供依据。同时,现场试验了多种控制措施防止白云岩含水层上段浆液严重超距扩散,得到延长凝结时间对提高注浆压力效果明显,并提出采取混合式注浆方式保证钻注效率。考虑下段地层可注性相对较弱,提出采用高压注浆增加注浆量以保证堵水效果。注浆过程中,地层透水率降幅明显,注浆结束后,各段地层透水率降低至0.5 Lu以下,地层由中等透水性地层转变为微透水地层。注浆结束后,压水试验得到回风井井筒地面预注浆堵水率为98.04%;1#进风井井筒地面预注浆堵水率为95.7%。研究成果可为西部地区类似条件下井筒防治水提供技术参考。
In order to solve the problem of shaft water disaster prevention in water rich dissolved dolomite formation in Southwest China,the characteristics of grout diffusion in dolomite aquifer were studied by field grouting test and numerical simulation.The field grouting test shows that the ultra thick dolomite aquifer of Laohudong phosphate mine is groutable,and the groutability of the upper section is obviously better than that of the lower section.Through water pressure test,borehole coring and COMSOL multiphysics simulation software,the reasonable borehole spacing for shaft pre-grouting is 4.5 m in the water rich dissolved dolomite aquifer of Laohudong phosphate mine,which provides a basis for the design of subsequent shaft ground pre grouting engineering.In addition,a variety of control measures have been tested to prevent the serious over-distance diffusion of the grout in the upper section of the dolomite aquifer.Prolonging the setting time has an obvious effect on improving the grouting pressure,and the mixed grouting method is proposed to ensure the drilling and grouting efficiency.Furthermore,high-pressure grouting is proposed to increase the amount of grouting to ensure the water shutoff effect considering the relatively weak groutability of the lower stratum.During the grouting process,the permeability of the stratum decreased significantly.The permeability of each section of the stratum decreased to less than 0.5 Lu after the grouting,and the stratum changed from medium permeable stratum to slightly permeable stratum.According to the water pressure test after grouting,the water sealing rate of surface pre-routing is 98.04%and 95.7%for the return air shaft and the No.1 air intake shaft.The research results of the present paper could provide technical reference for water controlling for shaft in similar geological conditions.
作者
周禹良
李斌
杨雪
ZHOU Yuliang;LI Bin;YANG Xue(Beijing China Coal Mine Engineering Co.,Ltd.,Beijing 100013,China;National Engineering Research Center of Deep Shaft Construction,Beijing 100013,China;School of Mechanics and Civil Engineering,China University of Mining&Technology-Beijing,Beijing 100083,China)
出处
《金属矿山》
CAS
北大核心
2022年第12期10-17,共8页
Metal Mine
基金
国家自然科学基金项目(编号:51874173)
天地科技股份有限公司科技创新项目(编号:2021-TD-QN004)。
关键词
溶蚀白云岩
巨厚含水层
井筒水害
地面预注浆
现场注浆试验
dissolved dolomite
ultra thick aquifer
shaft water disaster
surface pre-grouting
field grouting test
