深埋岩溶隧道水压力的预测与防治

研究目的:为保护洞顶水资源和环境,深埋岩溶隧道“以排为主”的设计原则巳不适应环保要求,开始尝试 “以堵为主”的防排水原则。封堵地下水会使隧道衬砌承受巨大水压灯,“以堵为主”的关键问题是预测和防治隧 道水压力。 研究方法:隧道水压力受地下水水头损失和地下水与衬砌接触面积的双重影响,据此在调整岩溶隧道水头 折减系数的基础上,分析隧道水压力模式。 研究结果:给出了用渗流水量确定隧道水压力的公式,继而讨论了基于水环境平衡的适度排水和围岩注浆 的防治原则,并给出了注浆圈和其内衬砌的水压力的计算公式。 研究结论:引用锦屏二级水电站探洞和渝怀铁路圆梁山隧道的实测资料对上述水压力公式进行检验,其计 算的隧道水压力较符合实际。

CALCULATION AND CONTROL OF WATER PRESSURE ON KAST DEEP TUNNEL

Research purpose:for protecting water resource and environment on tunnel, strengthening water drainage as a design principle can not meet the demand of environmental protection, with choking up underground water as a design principle of karst deep tunnel begin tried already. The tunnel lining endures huge water pressure when underground water is blocked up, in which a key problem is calculating and controlling water pressure on tunnel at choking up underground water. Research method: because the water pressure is influenced double by head loss and contact area between karst water and tunnel lining, based on regulate decrease coefficient of head on karst tunnel, analysis model of water pressure on tunnel. Research result::the formula calculating the water pressure on karst tunnel with vadose water discharge is advanced. Then, control principle with suitable drainage and grouting in country rock based on water environmental balance on the tunnel is discussed, and formulas calculating the water pressure on grouting circle and lining of tunnel are advanced. Research conclusionrabove formulas calculating the water pressure are tested with measured data in prospect cavity of the second Jinping hytropower plant and in Yuanliangshan tunnel of the Chongqing-Huaihua railway as an examples, and the water pressure values more conform to reality.