Construction Technology Of Pengshui Tunnel In The Complicated Geological Condition

Pengshui tunnel of Yuhuai railway is located between Tangkou station and Pengshui station, its total length is 9028 meters and its span is 21.78 meters wide. Many geological disasters exit in it, for example spouting, muddy, underground river, karst, gas, sliding-slope, rock-blasting and so on,it is difficult to construct that entrance section pass through coal measures layer and exit section have the characters of long span, shallow hidden and full of water. In this paper we do research on key technical problems during tunnel construction, the four problems are as follows.(1) Do research on tunnel passing through bad geological section. We adjust plans for excavation in time, strengthen protection, lining followed, reinforce anchored stake, grout pulp, close blast hole, which assure tunnel passing through bad sections successfully.(2) Do research on tunnel lining with no seepage and no leakage. We adopt measures such as smooth blasting, spraying and anchoring, water-proof board, concrete lining and so on, carry out comprehensive improvement of tunnel spouting and crevice water, no seepage and no leakage during tunnel lining has come true.(3) Do research on blasting controlled. According to different geological situation, gradation of rock, excavating section, we set different blasting plans and parameters, make plans of overall section smooth-face blasting, short distance smooth blasting, smooth layer reserved in advance in below diversion tunnel and upper diversion tunnel, slight shock smooth blasting for weak rock of long span section, good blasting results have been achieved .(4) Do research on fast construction in complicated geological condition. In accordance with progress of tunnel construction, we adjust plans of dregs transported in time, to realize compositions of construction patterns, such as"no railroad loading railroad transportation""railroad transportation changed into no railroad transportation in tunnel""railroad loading railroad transportation", which make the most of railroad and no railroad transportation, speed up construction progress.