A light piston well-flushing technique for clogged relief wells along Yangxin Dyke of Yangtze River in China

Abstract

Plastic relief wells along Yangxin Dyke of Yangtze River in China have been seriously clogged in recent years. It is necessary to dredge the wells to restore its disaster prevention and mitigation function. However, traditional piston well-flushing technique is suitable to restore steel and iron wells, and it can cause damage to plastic relief wells. A new light piston well-flushing technique is proposed to overcome the limitation of traditional piston well-flushing technique. The proposed light piston has the advantages of simple structure, convenient use and low cost. By the light piston moving down and up quickly the relief well, the nylon brush can clean the side wall and filters of relief well, and the negative pressure can make the deposited materials in the aquifer and inverted filter sucked out. The proposed well-flushing technique is applied to restore the plastic wells along Yangxin Dyke of Yangtze River in China. Its efficiency is illustrated using field pumping test data. It is shown that the drainage capacity and permeability of clogged relief wells can be greatly improved after using the proposed technique. The light piston well-flushing technique can provide an effective way to restore clogged relief wells along Yangtze River levees.