山西引黄工程南干线7# 隧洞衬砌外水压力研究

本文采用综合修正系数取代规范建议的单一折减系数,用渗流场分析方法确定作用在引黄入晋南干线7#隧洞衬砌上的外水压力。由己知钻孔水位及泉水位反演出各地层的渗透张量及地表入渗强度求得初始渗流场。衬砌外水压力分析中考虑了衬砌混凝土的渗透性以及排水、灌浆等工程措施的影响。根据分析结果,提出了系统排水孔布置的建议,得出了在相应的排水减压措施下衬砌厚度由原设计35cm减至25cm,这一建议已被采用,取得了巨大经济效益。

Study on external water pressure on lining of tunnel No 7 of south main of YRDP

The comprehensive correction coefficients were introduced to determine the external water pressure on lining of tunnel No 7 of the south main of Yellow River Diversion Project (YRDP) in Shanxi Province. In the calculation, the single revision coefficient specified in the Design Code was not used. The initial seepage was obtained and the permeability tensors of different rock strata and the intensity of infiltration were derived by means of back analysis according to the water levels in boreholes and the locations of spring.The external water pressure was obtained by applying finite element analysis (FEA), taking into consideration the relative permeability of concrete and rock mass and the effects of drainage hole and grouting. Based on the results, some suggestions were put forward. The thickness of concrete lining could be reduced from 35 cm to 25 cm. This proposal was accepted and a large amount of investment was saved.