袋装淤泥质土挡墙现场试验研究

Field tests on retaining wall constructed with soilbags filled with clayey soils

在平原地区航道建设过程中,航道开挖会产生大量的淤泥质土,将开挖的淤泥质土装入土工袋用于修筑引航道挡墙,能够有效解决开挖淤泥处理的问题。结合苏州杨林塘航道整治工程,利用航道开挖的淤泥质土,通过室内无侧限压缩与固结试验研究了土工袋处理淤泥质土的作用原理;对100m长的袋装淤泥质土挡墙试验段开展了现场试验,实测了挡墙施工过程中与竣工后的水平位移、侧向土压力及表面沉降。结果表明土工袋能够加速袋内土体固结,增大袋内土体强度;竣工7个月后实测墙体最大水平位移为29.42mm,发生在挡墙顶部,墙顶面沉降位移为19.2cm,基本达到稳定;由于土工袋层间摩擦作用,土工袋挡墙墙后土压力从墙内向墙外会逐渐减小;与常规重力式混凝土挡墙相比,所设计的袋装淤泥质土挡墙能够有效降低工程造价。

In the construction of approach channels in a plain area, a lot of clayey soils are excavated. If the excavated clayey soils are filled into woven bags, they can be used to build retaining walls. The principle of treating clayey soils with soilbags is studied through laboratory tests. A 100-m testing retaining wall constructed with soilbags filled with clayey soils was designed and applied in the Yanglintang channel project. The behaviors of the retaining wall are studied through the field monitoring of the lateral deformation, lateral pressures and surface settlements of the retaining wall. The test results show that the soilbags can benefit the consolidation of clayey soils in the bags and increase their strength. The monitored maximum lateral deformation and the surface settlement of the retaining wall are 29.42 and 19.2 cm respectively after 7 months of the completion, hence quite stable. The lateral earth pressure on the front retaining structure is positively reduced owing to the interlayer friction of soilbags. The cost of the retaining wall constructed with soilbags has an obvious advantage over that of the conventional gravity concrete retaining wall.