【作者】 江新冬；

【导师】 龚晓南；

【作者基本信息】 浙江大学 ， 建筑与土木工程， 2008， 硕士

【摘要】 随着浙江沿海社会经济的日益发展,对电力的需求越来越迫切,变电所等电力建设工程日益增多。由于浙江沿海地区土质条件差,广泛分布着深厚的软土层,主要为淤泥和淤泥质土,该土层具有含水量高、渗透性差、强度低、孔隙大、低密度并具一定的结构性的特点,其分布往往不均匀,并且地势较低,需要大面积填土,因此给变电所的地基处理带来了较大困难。目前软土地基处理方法很多,真空预压法是软弱地基处理较为有效的方法之一,由于目前真空联合堆载预压方法在加固机理、施工工艺等方面的研究不多。本文结合具体的工程实践,对真空联合堆载预压加固软土地基的机理、施工工艺、设计及现场监测进行了比较深入的分析,得到了下列有益于工程研究和应用的结论:1.真空作用下的地基土产生收缩变形,不会发生侧向挤出,同时能抵消相应的堆载作用下产生的土体的挤出力。改善了填土速度问题,但是如果加载速率过快也会导致堆载失稳。2.真空预压一般适用于地质剖面存在无透水底层或均质型粘性土的软土地基中,适用加固浙江沿海变电所软基。只有保证排水系统、密封系统、抽真空系统等的正常,才能使真空联合堆载预压取得成功。3.通过现场观测资料分析,采用真空联合堆载预压法加固变电所软土地基,不仅加固效果较好,而且加固深度深,可以消除一定的工后沉降,比较适合加固变电所场地的深厚软基。更多还原

【Abstract】 With the coast of Zhejiang’s social and economic development in the growing, the demand for electricity has become an increasingly pressing, such as the electricity substation construction project on the rise. Zhejiang’s coastal areas due to poor soil conditions, the distribution of a wide range of deep soft soil, mainly mud and silt soil, the soil has a high water content, poor permeability, low strength, porosity, low-density and a certain amount of structural Its distribution is often uneven and low-lying, need to fill a large area, the substation to the ground treatment has brought more difficulties. There are many ways to deal with the current soft ground, pre-vacuum pressure is weak foundation to deal with one of the more effective way, as there is a vacuum preloading a joint approach in the mechanism of reinforcement, construction techniques and so on the little research. In this paper, concrete engineering practice, the joint vacuum preloading mechanism of reinforcement of soft soil, construction technology, design and on-site monitoring carried out a more in-depth analysis, the following has been beneficial to the engineering study and application of the conclusions:1. Vacuum preloaded the soil deformation resulting contraction will not occur out of the lateral and at the same time be able to offset the surcharge under generated out of the soil, improving the speed of filling, but if the loading rate over Will quickly lead to instability surcharge.2. Vacuum preloading generally applicable to non-existence of the geological section of the bottom water or homogeneous type of cohesive soil in soft soil for reinforcement of coastal Zhejiang-based soft substation. To ensure that only the drainage system, sealing systems, vacuum systems, such as normal to make a joint vacuum preloading test successfully.3. Observational data through on-site analysis, the joint use of vacuum preloading law substation soft soil reinforcement, strengthening not only better but also reinforced the depth of deep, must be able to remove the settlement after more suitable for strengthening substation sites the soft-deep.更多还原