Abstract Artificial recharge measures have been adopted to control the drawdown of confined aquifers and the ground subsidence caused by dewatering during deep excavation in Tianjin, Shanghai and other regions in China. However, research on recharge theory is still limited. Additionally, confined aquifers consisting of silt and silty sand in Tianjin have lower hydraulic conductivities than those consisting of sand or gravel, and the feasibility and effectiveness of recharge methods in these semiconfined aquifers urgently require investigation. A series of single-well and multiwell pumping and recharge tests was conducted at a metro station excavation site in Tianjin. The test results showed that it was feasible to recharge silt and silty sand semiconfined aquifers, and, to a certain extent, the hydrogeological parameters obtained from the pumping tests could be used to predict the water level rise during single-well recharge. However, the predicted results underestimated the water level rise near the recharge well (within 7 m) by approximately 10–25%, likely because the permeability coefficient around the well was reduced during the recharge process. Pressured recharge significantly improved the efficiency of the recharge process. Maintaining the recharge and pumping rates at a nearly equal level effectively controlled the surrounding surface and building settlement. However, the surrounding surface subsidence tended to rapidly develop when recharge stopped. Therefore, the recharge process should continue and gradually stop after the pumping stops. The twin-well combined recharge technique can be used to control the head loss of an aquifer when one of the recharge wells requires pumping to solve the associated clogging problems.

中文翻译：

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深基坑工程半承压含水层人工补给试验研究

摘要 我国天津、上海等地区已采取人工补给措施控制承压含水层的水位下降和深部开挖脱水引起的地面沉降。然而，对补给理论的研究仍然有限。此外，天津由粉砂和粉砂构成的承压含水层的导水率低于由砂或砾石构成的含水层，这些半承压含水层的补给方法的可行性和有效性亟待研究。在天津某地铁站开挖现场进行了一系列单井和多井抽水回灌试验。试验结果表明，补给粉砂和粉砂半承压含水层是可行的，并且在一定程度上，从抽水试验中获得的水文地质参数可用于预测单井补给期间的水位上升。然而，预测结果低估了补给井附近（7 m 以内）的水位上升约 10-25%，这可能是因为在补给过程中井周围的渗透系数降低了。加压补给显着提高了补给过程的效率。将补给率和抽水率保持在几乎相等的水平，有效地控制了周围的表面和建筑物的沉降。然而，当补给停止时，周围地表下沉趋于迅速发展。因此，在泵停止后，再充电过程应继续并逐渐停止。