The region belong to high geostress area . in the preceding excavation of 4km long exploratory tunnel , several bigger flows had taken place . the maximal flux approached 4 . 91m3 / s and the maximal water pressure is 10 . 22mpa 在前期4km長探洞施工過程中,曾發(fā)生多次較大涌水,單點最大涌水量達4 . 91m ~ 3 s ,長探洞封堵后最大水壓力達10 . 22mpa ,工程區(qū)高外水壓力問題突出。
In addition , this paper carry out successfully the support design practice in the preceding excavation of 4km long exploratory tunnel . according to the thesis research results , the following conclusion can be drawn . if the grouting rock can possess sound anti - seepage capability and the liner structure can hold higher hydraulic permeability relatively , and if the adjoining rock can be made as primary load - bearing structure by construction measure , the stability of country rock and the safety of liner structure will be guaranteed 計算結(jié)果表明,如果能使錦屏工程引水隧洞灌漿圈圍巖具有較好的防滲性能,將高外水壓力控制在灌漿圈以外,再配合透水性相對較好的支護結(jié)構(gòu)以及排水措施,使灌漿圈圍巖成為主要承載結(jié)構(gòu),并使襯砌結(jié)構(gòu)和灌漿圈共同承載,是可以保證圍巖的穩(wěn)定和支護結(jié)構(gòu)安全的。