塑料排水板处理软土地基的离心模型试验研究

采用大型土工离心机对某海上机场工程近海软土地基上堤坝施工期及运行期进行了模拟。原型中采用塑料排水板固结法处理软土地基,模型中则根据固结过程相似的原理,换算成等效圆截面排水体,在模型制作中采用等效透水滤芯来模拟。试验中采用停机加载法模拟分级施工加载过程。根据激光位移传感器试验数据可以计算得出相应原型软土地基的沉降特性。利用试验得到的沉降曲线,采用"经验双曲线法"推算出了地基最终沉降,然后得出按沉降推算的分层地基平均固结度随时间的变化。对比沉降推算的运行5 a时软土地基固结度和理论计算结果,二者基本接近,表明文中塑料排水板的模拟方法用于离心模型试验是可行的。通过与理论计算结果比较,表明试验采用的塑料排水板模拟方法是可行的。

Centrifugal model tests on vertical strip drains in soft soil foundation

Centrifugal model tests are carried out to simulate the construction and operation of the dike on a soft soil foundation for the purpose of taxiway construction on the seashore. The vertical strip drains are adopted for the soft foundation treatment and they are simulated by a kind of model cylinder vertical drains in centrifuge models based on the principles of the same consolidation degree in the foundation in average for both types of drains. During the model tests, the construction processes are also simulated by loading dike materials layer by layer. Laser displacement sensors are installed for settlement measurement. Based on the test data, the final settlement of the dike is estimated by using the empirical hyperbolic method. The consolidation degree of the foundation over time is also calculated by getting the average consolidation degrees of the sludge and the sand under the dike. By comparing the simulated consolidation degree of the soft foundation after 5 years operation based on the test results of settlement with that of the theoretical calculation, it is shown that the proposed simulation method for vertical strip drains is feasible and acceptable.