大隆水利枢纽工程高喷板墙施工

Construction of jet grouted barrier wall in Dalong Water Control Project

为保证大隆水利枢纽工程防渗墙施工质量及确保堰坝度汛安全,在坝体上游设置一道高喷板墙。要求高喷墙渗透系数小于i×10-5cm/s,并与土和强风化层之间有良好的连接。工程具有地层复杂钻孔难度大、喷射灌浆条件多变的特点。高喷板墙完工后,通过围井注水试验检查质量,渗透系数为1.56×10-6cm/s。工程实践表明:在卵砾石含量多、粒径大的地层中,选择钻进能力强的钻孔设备、采取跟管钻进和PVC管护壁技术,是确保高喷灌浆成功的重要条件。

In order to ensure the construction quality and the safety of the dam during the flood period for Dalong Water Control Project, a jet grouted barrier wall is placed in front of the dam, for which the permeability coeffiecient under i × 10^-5 cm/s and better connection between the soil and stronger weathered layer are required. The construction has the features such as difficulty of drilling into the complicated stratum and jet grouting under various conditions. After the completion, the permeability coeffiecient of the wall is 1.56 × 10^-6cm/s obtained through the quality examination with water-injection test. The engineering practice shows that the important condition for successful jet grouting into the stratum with high gravel content is to use the driller with high drilling capacity along with the techniques of follow-down drilling and wall protection of PVC pipe.