【作者】 夏彩虹；

【导师】 佴磊；

【作者基本信息】 吉林大学 ， 地质工程， 2004， 硕士

【摘要】 塑料排水板是淤泥、淤泥质土、冲填土等饱和粘性土及杂填土运用排水固结法进行软基处理的良好垂直通道，大大缩短固结时间。在软土地基处理中，排水板的作用、设计、施工设备基本与袋装砂井相同，但较袋装砂井的综合成本降低30%,施工速度快1/3。塑料排水板是带状复合型结构，中间是挤出成型的塑料芯板，是排水带的骨架和通道，其断面呈井联十字，由35条筋，34条槽组成，宽100mm,厚3.5--6.0mm。芯板外部包复化纤无纺布，起着隔土滤膜作用。我国南方沿海等地区广泛分布着淤泥、淤泥质土、冲填土等软弱粘土层，这种土的特点是含水量大、压缩性高、强度低、透水性差且不少情况埋藏深厚。由于以上特点，在建筑荷载作用下会产生相当大的沉降和沉降差，而且沉降延续的时间长，严重影响建筑物的正常使用。对于这种地基处理，使用排水固结法就广为利用，大量工程处理实例证明该方法是行之有效的软基加固方法。排水固结法是通过加压和排水的共同作用使得饱和软土排水固结，消除大部分沉降，提高密实度和强度的一种方法，它由排水系统和加压系统组成，它是淤泥、淤泥质土、冲填土等饱和粘性土及杂填土最好的地基处理方法。该方法的加压系统为预压土石，是利用建筑物的自身重量(比如路堤土等)作为预压荷载，加固结束后不再卸载，从而可节约投资和缩短工期。排水系统为砂垫层和塑料排水板。固结机理为软土受上部荷载的作用而压缩，孔隙水受压而沿塑料排水板和水平砂垫层排出，孔隙水压力随之减少而相应有效应力增长，且孔隙水压力减少量等于有效应力增长量，随着孔隙水压力逐渐向有效应力的转化，软土得到固结。目前软基处理中排水固结法常用的方法有塑料板排水真空预压法、袋装砂井真空—堆载联合预压法、塑料板排水堆载预压法、动静结合排水固结法。由于本次研究中路基土为软弱泥炭质淤泥、粉质粘土、粉土，土层含水量大、压缩性高、强度低、透水性差，根据其土质情况该地基<WP=60>可以采用塑料板排水堆载预压法。为了引进和推广塑料板排水堆载预压法在东北地区的应用，研究决定采用塑料板排水堆载预压法进行软土路基处理。虽然塑料板排水堆载预压法在我国南方沿海等地区的应用已经很普遍，但是在东北严寒地区尚无应用该方法的先例，因此本次研究对东北地区软土路基处理方案的补充有着重要的意义。本文主要是在现场勘察、原位测试和室内试验所得数据资料的基础上进行综合研究，主要研究内容包括哈尔滨环城高速公路软土路基地基土的野外分布、野外特征、基本物理力学性质，以及地基土的最终沉降量计算、设置塑料排水板前后地基土沉降随时间的变化关系研究、沉降监测资料的反分析计算、软土路基处理的结果。此次应用研究在东北地区尚属首次，这能为今后东北寒冷地区软土路基处理工程采用该方法提供借鉴意义。近年来，我国虽然在塑料板排水处理软基方面已取得相当大的成就 ,但也还存在不足。土工材料的质量和性能还不够完善 ,没有合理控制施工质量的方法 ,井阻和涂抹的研究还很不够 ,可见塑料板处理软基的研究还有大量工作要做。本次研究是针对东北地区首次采用塑料板排水堆载预压法的研究，研究属于初步阶段，随着今后工作的开展和研究的进行，将会得到不断完善的发展。更多还原

【Abstract】 Prefabricated drains are good vertical pathway in dealing with soft soil foundation such as slime, muddy soil, alluvial and aggradational soil etc. saturation viscidity soil and disorder heaping soil. with drainage consolidation. The time of consolidation can be shorten greatly. The act, design and construction equipment of the prefabricated drains are basically similar to sacked sand well in dealing with soft soil foundation, but the combined cost of former reduces 30% than that of the later, the construction speed of the former is faster than that of the later about 1/3. Prefabricated drains are banding composite framework with core board by piling out shaping in the middle. the core board is skeleton and pathway of plastic board, its cross-section is parallel cross and made up of 35 ribs and 34 arks.The width of the prefabricated drains is 100 mm and their thickness is from 3.5 to 6.0 mm. There is composite chemical fiber spin fabrics outside core board that can stop soil and act as a straining membrane.There are many soft soils as slime, muddy soil, alluvial and aggradational soil in the coastal area of south China, water content of these soft soils is heavy, compressibility is high, intensity is low and water permeability is bad with deeply buried in many situation. Because of the above characteristic, the subsidence and subsidence difference of the building will be large, the time of settlement will be much longer under the loading of the building itself. The normal using of the building will be impacted seriously. The drainage consolidation law can be used widely to reinforce those soft soil foundation, this method is proved to be effectual by a large number of project.The saturate soft soil can be drained and consolidated with the act of the pressurization and drainage system during the drainage consolidation. With this method majority subsidence of the soft soil is dispelled and the density and strength of the soft soil are improved. Drainage consolidation method <WP=62>consist of pressurization and drainage system. The way is the best method in treating slime, muddy soil, alluvial and aggradational soil etc. saturation viscidity clay and disorder heaping soil foundation.Its pressurization system is preloading earth and rock, the preloading load is the load of the building itself,unload need not be done after strengthening, then it will be economical in the construction cost and the construction period will be shorten. The drainage system consist of sand cushion layer and prefabricated drains.Drainage consolidation principle is following: with the top load soft soil is compressed and pore water is out along with prefabricated drains and horizontal sand cushion layer. The pore water pressure is down and correspondent effect stress is up, the quantity of the depletion is equal to the increment, with the pore water pressure turning to the effect strength, the soft soil is consolidated.Vacuum preloading draining with prefabricated drains, combined vacuum-surcharge draining with sacked sand well ,stack-load preloading draining with prefabricated drains and combined active and stationary draining consolidation method are used commonly in reinforcement of the soft soil foundation at present . The soft peat slime,silty clay and silt are the all soft soils of the road foundation in this project. water content of these soils is heavy, compressibility is high, intensity is low and water permeability is bad. According to this propety, the stack-load preloading draining with prefabricated drains can be applied in this project. In order to introduce and popularize this method applied in northeast China, through study on this project this method was adopted to reinforce soft soil road foundation.Although stack-load preloading draining with prefabricated drains has been widely used in coastland of south China, there is no precedent in severe cold area of northeast China. So this study is important to the supplementary reinforcement of soft soil foundation in northeast China.Synthetic research on the project更多还原