【作者】 郭强；

【导师】 张莎莎； 包卫星；

【作者基本信息】 长安大学 ， 工程硕士 交通运输工程（专业学位）， 2017， 硕士

【摘要】 湿陷性土是指在上覆土层自重作用下,或者在自重应力和附加应力共同作用下,因浸水后土的结构破坏而发生显著附加变形的土。黄土是第四纪的一种特殊堆积物,即一种以粉粒为主,天然含水率小,多孔隙,呈黄色、褐黄色,含钙质的粘质土。我国东北、西北、华中和华东地区的黄土多具有湿陷性,建(构)筑物建造在湿陷性土上,经常会出现与湿陷性相关的危害,黄土状土的湿陷特性是引起路基破坏的主要因素。根据资料统计显示,新疆维吾尔自治区伊犁哈萨克自治州境内已建成的35%的国省道干线公路路基均以黄土状土为主,黄土状土的湿陷特性使道路频繁发生不均匀湿陷,给车辆通行带来巨大的安全隐患。湿陷性土的形成原因、化学和物理性质、分布的范围以及强度越来越被人们所熟知。在湿陷性土路段施工中,人们通常会关注选用什么样的处理方法能更加经济有效的达到处理效果。目前工程建设中大多数采用以下几种方法:强夯、换填砂砾垫层、冲击碾压法、挤密桩法等。故湿陷性黄土的研究与处理在工程界占有特殊地位。本文主要针对新疆伊犁州黄土区域的公路建设情况,依托省道315线蜂场至尼勒克公路建设项目,对伊犁地区湿陷性土的物理、力学性质,路基处理方案和效果、施工工艺做出了评价。并且通过现场试验和数值计算,系统地研究了强夯、换填砂砾垫层、冲击碾压和挤密桩等施工工艺及其地基处理效果。通过对以上多种处理方法的试验和数值分析,认为强夯、换填砂砾垫层、冲击碾压和挤密桩等地基处理方法,对于处理伊犁地区湿陷性土也一样适用。但也应该注意,不同湿陷性土的地基处理方案有其各自的特征和适用范围,所以在施工中应灵活掌握,使治理效果达到最好、最经济有效。更多还原

【Abstract】 Collapsible soil refers to the soil under the action of the self-weight of the overlying soil layer,or under the combined action of the self-weight stress and additional stress,due to the structural damage of the soil after water immersion and significant additional deformation.Loess is a special deposit of quaternary,i.e.a clay mainly composed of silt,small natural moisture content,porous,yellow,brown yellow and calcareous.According to the data statistics,35 % of the main highway subgrade in Yili Kazakh autonomous prefecture of Xinjiang Uygur autonomous region is mainly loess soil,loess soil collapsibility characteristics make the road frequent uneven collapsibility,which brings great security risks to road traffic.Loess in northeast China,northwest China,central China and east China is mostly collapsible,and the building(structure)is built on collapsible soil,often appear related to the damage of collapsible,the collapsible characteristics of loess soil is the main cause of subgrade damage.Therefore,the research and treatment of collapsible loess occupies a special position in the engineering field.The causes,chemical and physical properties,distribution range and strength of collapsible soils are becoming more and more well known.There are many methods to treat collapsible soil.according to different treatment horizons,collapsible soil treatment can be divided into surface treatment,subsurface shallow treatment and subsurface deep treatment.According to the different treatment methods,collapsible soil treatment can be divided into: surcharge preloading,reinforced embankment,back pressure protection,granular bedding,riprap siltation,dynamic compaction displacement,consolidation and drainage methods.In the construction of collapsible soil section,people often pay attention to what kind of treatment method can be more cost-effective to achieve the treatment effect.At present,most of the engineering construction adopts the following methods: dynamic compaction,replacement of gravel cushion,impact rolling,compaction pile method,etc.In this paper,the physical and mechanical properties,subgrade treatment scheme and effect,and construction technology of the collapsible soil in Yili area are evaluated according to the highway construction situation in the loess area of Yili prefecture,Xinjiang,relying on the highway construction project from shengdao 315 line bee farm to nileke.Through field test,the construction technology and foundation treatment effect of dynamic compaction,replacement of gravel cushion,impact rolling and compaction pile are systematically studied.Through the test of the above treatment methods,we think that the foundation treatment methods such as dynamic compaction,replacement of gravel cushion,impact rolling and compaction pile are also applicable to the treatment of collapsible soil in Ili area.But it should also be noted that the different collapsible soil foundation treatment plan has its own characteristics and scope of application,so in the construction should be flexible to master,so that the best treatment effect,the most economic and effective.Finally,several treatment methods of collapsible soil foundation are summarized and prospected.更多还原