基坑降水计算中应用裘布衣公式的问题

Issues on applications of Dupuit's equation in the calculation for dewatering of foundation pit

本文讨论了裘布衣稳定流理论应用在基坑降水计算中存在的问题,包括假设的稳定流和实际的非稳定流问题,假设平缓的水力梯度与实际的大降深问题,影响半径的逻辑矛盾问题,弱透水层的阻隔和渗出面问题,数值法计算问题等。裘布衣稳定流理论简单,局限性也很明显,计算者务必十分注意实际情况与理论假设之间的差别及其带来的后果,慎重使用。

Some issues existed in the calculation for the dewatering of foundation pit with Dupuit＇s steady flow theory are discussed,which include the issue between the assumed steady flow and the actual unsteady flow,the issue between the assumed gentle hydraulic gradient and the actual big drawdown,the issue on the logical contradiction from influence radius,the issue between the barrier of the weak permeable layer and the seepage face and the issue on the numerical calculation.Dupuit＇s steady flow theory is simple,but its limitation is obvious.The calculator should highly pay attention to the differences between the actual conditions and the theoretical assumptions and to the consequence form the differences,and carefully use it.