【作者】 肖礼经；

【导师】 邵旭东； 胡建华；

【作者基本信息】 湖南大学 ， 建筑与土木工程， 2003， 硕士

【摘要】 轻质材料是指使用人工材料制作的表观密度较低，而强度较高的材料，其主要特点是表观密度比一般的土体小，而强度和变形特性可以达到甚至超过良好土体。泡沫水泥轻质土具有良好的流动性、水硬性、施工性及经济性等特点，应用前景非常广阔。 本文详细介绍了泡沫水泥轻质土材料的基本性质，一般其表观密度在500～1500kg／m~3的范围内调整；其抗压强度可以在0.1～1.5MPa的范围内进行调整；其流动性指标即扩展度在180±20mm左右。浸水后表观密度有所增加，增加幅度约8％左右。在实际应用时，其自身的压缩下沉量可以忽略不计，其抗剪强度约为单轴抗压强度的1／3左右。若将反复疲劳荷载控制在单轴抗压强度的50％左右时，其对强度的影响可以忽略不计。 对于泡沫水泥轻质土用于路堤等设计的具体理论，本文亦作了具体论述，设计时应考虑背面土压、水压、自重、上部载荷、水平土压力、浮力、地震力、冲击力等因素以及不同条件下的安全系数，其稳定分析项目包括局部稳定分析与整体稳定分析。 本文对泡沫水泥轻质土的实际应用也作了详细介绍，施工时，应根据设计条件事先进行配合比设计，以确认原料土的性质、轻质土表观密度、强度和施工的流动性及材料抗离析力。其施工工序为：挖掘、整地→防、排水工程→挡墙工程→发泡、混合搅拌→输送→浇注、铺设→养生保护。其施工时质量控制重点为确认其是否达到了规定的流动性和表观密度。 泡沫水泥轻质土具有广阔的应用前景，可以进行垂直填土，保护环境；作为路基填料能有效控制道路工后沉降并增大稳定、安全系数；可以减轻路堤自重，降低地基应力，提高结构物使用的安全性及使用寿命，能有效消除桥头跳车现象。 本文的研究对于公路建设中的软基处理、桥头处理、公路扩幅等问题的解决提出了一种新的方法和理念。更多还原

【Abstract】 As a kind of geotechnical material, light material is made of artificial materials, the primary character of which is that it is lighter than common soil while the intensity and the deformation feature may be equal to or even be better than good soil. Foamed Cement Banking (FCB), a kind of light material, is mainly discussed. Possessing of the good qualities on flowability, self-hardening, construction and economy, FCB gets a very wide application foreground.The substantial behavior of the FCB material is introduced thouroughly in this paper. Generally, the apparent density ranges between 500 and 1500 kg/m3 while the compression strength varies from 0.1 to 1.5MPa. Because FCB is fluid and self-hardening, the flow value is often controlled at about 180?0mm. The apparent density of FCB has an increasing of about 8 % atter immersion. The compression settling of FCB itself can be ignored in practice. The flexural strength is in a proportion of about 1/3 to the one-axis compression strength and the effect on strength can be ignored.The specific design theory for the FCB material when it was applied in the design of embankment and etc. was also presented in the paper. In specific design, the following loading factors should be taken into account: back soil pressure, water pressure, dead weight, overburden, horizontal soil force, buoyancy, seismic force and impact force. The different safety factors under different conditions should also be considered. The items concerning the stability can be divided into two aspects, for example, internal stability and external stability.Furthermore, the actual application of the FCB is introduced in the paper. The mix design of FCB should be performed according to the design conditions before construction. In the design, the properties of raw soil, the apparent density and strength of light soil, the flowability in construction and the resistance disassociation should be given. The following are the construction process steps: digging, preparing soil drainage andwater-proof project retaining wall works foaming, mixing and agitating transferrin placing, layin curing maintenance. The key point of FCB quality control is to make it clear whether FCB has reached its flowability and apparent density specified.It is obvious that the FCB material will get a very wide application foreground in future. FCB can be used for vertical filling to make the best of limited soil resource and to protect environment, for bank-filling on soft-base to control the post subsidence efficiently and to promote the stability and the security, for filling behind structures, such as abutment, to reduce the subgrade stress and to lessen the soil pressure supported by the back of the structures as much as possible by lighten the embankment greatly with the ultimate object is to improve the structures’ using safety factor and to prolong the using life, and then to eliminate the jumping at bridge-head.A new method and concept are presented in the paper for the settlements of the problems in road construction, which includes soft-base treatment, jumping at bridge-head and pavement widening.更多还原