自重湿陷性黄土地基预钻孔浸水处理的可靠度设计方法

为解决传统预浸水法存在的浸水时间长、浸水处理范围难以确定等不足,基于土体中水分运移规律,依据可靠度理论、极限状态设计方法及复合 Poisson 过程原理,提出一种消除黄土湿陷性的处理浸水方法——预钻孔浸水法。给出了利用预钻孔浸水法对自重湿陷性黄土地基进行浸水时,水平向及竖直向浸水影响范围的确定模型;在此基础上结合达西定律给出了浸水孔设计参数如孔深、孔间距及浸水孔个数的确定方法。结合铜川某工程,设计进行了现场预钻孔浸水试验,对该方法的合理性进行了验证,并通过现场钻探、现场勘探、室内湿陷性试验等方法对该方法的处理效果进行了评价。该浸水方法具有浸水时间短、浸水影响范围可根据浸水孔布设进行控制等优点,且浸水处理效果良好,完全符合施工要求。

A Reliability-based Method of Borehole Pre-immersion Treatment for Self-weighted Collapsible Loess Foundation

Traditional pre-immersion method requires long immersion time with the scope of immersion treatment difficult to determine. In view of this, a borehole pre-immersion method to eliminate the collapsibility of loess is proposed in line with the law of water movement in soil based on the reliability theory, the limit state design method and the compound Poisson process principle. The deterministic model of the horizontal and vertical immersion influence range is given. On this basis, the method of determining the parameters of water immersion holes such as hole depth, hole spacing and the number of holes is given in association with Darcy’s law. Combined with a project in Tongchuan, the rationality of the proposed method is verified by borehole pre-immersion test on site at Tongchuan, and the treatment effect of the method is further evaluated through on-site drilling, on-site exploration, and indoor collapsibility test. The proposed immersion method is proved to be of short immersion time, controllable range of immersion influence via the layout of immersion holes, and sound treatment effect, which fully meets construction requirements.