School of Construction Management，Jiangsu Vocational Institue of Architectural Technology，Xuzhou 221116,China;Stae Key Laborutory for CGeomehanios & Deep Underground Engineering ,China Unirersity of Mining &Technology; Xuzhou 2.1116,China

Groundlwater is a great rik in the construction of underground engineering. In pore water bearing rmock , because of poor pluggingresult of the grouting technology , the advese effects of high-pressure pore water is paticularly significant. To research the hydlraulic loadon the waterproof lining sumroundedl in pore waler bearing rock, a modlel test which waterprof lining was simulated by a metal tube and thesuroundling rock was substitutel by a porwus similar material was carriedl out. The hydraulic load was calculated by the measured strain data of the similar lining under different pore water pressure. Also, the relationship between the hydlraulic load and the pormosity of sutround-ing rock as well as the contact state between surroundling rock and the lining were analyzed. T'he results show that when the suroundingrock and lining are fully in contact, the hyraulic load on the waterproof lining is significantly smaller than the pore water pressure , the in-fluence coefficient of pore walter presure is about twice of the rock pomsity.After the lining gradually peels off the surroundling rock , hy-draulic load increases rapilly and the load value can reach the value of the pore water presure.F urthermore, the hydraulic load is negr-tive correlation of the contact ratio between waterproof lining and the surounding mock.Therefore , reducing the porosity and avoiding thestripping of contact surface can decrease the hydraulic loal. Fimally , the design principle of the waterproof lining in pore water bearingrock is put forwardl , that improving the bond strength between the lining anmd the surroundling ock to increase the interaction of them canreduce the risk of the construction of underground engineering.