真空井点降水联合加固软土地基的试验

为了在实际工程中有效应用加固软土地基,在松花江漫滩地区进行了真空井点降水联合方法试验研究.采用太沙基有效应力原理并结合观测得到的数据,对真空井点降水联合预压加固软土地基的机理及加固有效深度、有效应力的变化问题进行了理论分析.试验结果表明:砂井中的孔隙水压力下降速度较快,土体中的孔隙水压力下降则缓慢.地下水位的降低程度对真空降水预压方法加固效果有很大影响,"水封"作用不利于土体固结.通过真空预压和降水预压,不仅提高地基的固结速度和固结程度,且能提高边坡和地基的稳定性.在松花江沿岸地区或类似工程场地条件下应用真空降水预压方法加固地基是合理有效的.

Experimental study on the combined method of vacuum well-point dewatering and preloading

In order to apply the soft clay subsoil effectively in practice,the method of vacuum well-point dewatering and preloading was put to test in flood land of Songhuajiang River. Based on the real engineering data observed in practice and effective stress theory of K.Terzaghi,the mechanism of improving the soft ground by vacuum well-point dewatering and preloading and the change of effective stress and effective reinforcement depth were studied.The experimental results show that pore water pressure descends quickly in sand drain but slowly in soil. The decrease of groundwater level has great influence on preloading effectiveness.The effect of water closing does harm to soil consolidation.The method of vacuum well-point dewatering and preloading can not only increase the degree and speed of consolidation but also improve the stability of side slope and the soil. It is reasonable and effective to apply the method of vacuum well-point dewatering and preloading to the consolidation of littoral area of Songhuajiang river and similar zones.