深水下浇筑止水垫

Concreting Geout Pad of Stopping Waterunder Deep Water

云驾岭矿主井掘至288m被淹,分析堵水方案,确定止水垫参数和施工方法,把涌水433m^3/h全部堵住。

Mainshaft of Yunjialing is 5 m in net diameter and 451 m in depth. It met middle granular sand stone with grey carbonaceous siltstcne interstratified beds, which are soft and broken, when sinking to 287 m in depth and easten wall of shaft suddenly fell down,water rushed into shaft. Shaft was inundated by water which rushed into shaft raised from 20 m^3/h to 433m^3/h and could not pumped out. Some technical measures were considered to treat flooding accident. Pumping water out with high-lift and high flow pump is unreliable and high cost. It is difficult technically to concrete water stopping because of deep shfat. Groutpad of water stopping formed by grout and crushed stones was adopted last.Small diameter steel pipe which was water pipe before was hung in the centre of the shaft.The distance between the end of the pipe and shaft bottom is 200 mm. Throw crushed stones into shaft and make thickness of crushed stones layer achieve at the fixed thichness. Grout with thickness of 0. 8 to 0. 1 at pressure of 12 Mpa was grouted into layer of crushed stones until volume of grout achieve designed volume and grout fully fills gaps among crushed stones. The layer formed by grcut and crushed stones is cured for 7 to 8 days and condensed. Inflow of 433 m^3/h was stopped. Rate of stopping water is 100%; layer is not able to leak water at pressure of 2.2 MPa.