动力排水固结模型试验装置的研制

为了实现大尺度室内模拟动力排水固结法来加固吹填粘性土，本文特设计了室内试验装置。该装置由模型槽、动力装置、夯锤以及监测和数据采集系统等4部分组成，其主要特点有:(1)可同时实现半模和全模试验，可模拟单点夯和全夯，弥补了目前只有半模或1/4模和单点夯等小尺度模型试验的缺陷；(2)可实现实时观察立面裂隙、特征点的变化，对孔压、位移、动应力等进行实时监测和采集；(3)可实现自动起吊和自动脱锤，可以很好地模拟现场施工工况；(4)可实现以下加固工况的模拟实验:不同的夯击参数、不同的加固土层厚度、不同的排水方式等，从而达到不同加固方案的对比，优化加固方案；(5)拆装方便，还可用于模拟边坡、路基、挡墙、滑坡等，适用性较广。目前利用该模型装置已进行了两组不同排水系统的模型夯击试验，试验设备运行良好，可满足试验要求。

DEVELOPMENT OF EXPERIMENTAL APPRAPUS FOR LARGE DYNAMICAL CONSOLIDATION TEST WITH DRAIN

An experimental apparatus for large dynamical consolidation with drain is developed. It can be used to carry out the laboratory model test to consolidate the dredger fill. The apparatus includes soil container, lifting appliance, hammer rans, measuring and data acquisition units. The main characteristics of the equipment are: (1) It can realize both half-model and complete-model tests and can simulate multi-points rammer besides one-point rammer. (2) It can realize real-time observation of the vertical fractures in soil and the movements of measuring points. It also can take real-time measuring and data acquisition of pore press, displacement and active stress. (3)It can simulate the field construction quite well through automatic lifting and ramming. (4) Different consolidation methods such as tests with different ramming parameters, different thickness of consolidated soil, different drainage system etc can be modeled with the apparatus. The model test results can provide the best design parameters, i.e. the best parameters used in the field dynamic consolidation with drains to consolidate soft clay soil; (5)The equipment is very convenient to dismantle and combine. It can be used to simulate many situations such as slope, roadbed, retaining wall and landslide. Two model tests with different drainage systems have been carried out using the apparatus. The apparatus kept a good working state during the long test period of 6 months. 