温度荷载引起的饱和粉质黏土的超固结效应试验研究
发布时间：2019-04-20 13:13
【摘要】：温度对饱和粘性土力学特性的影响是近年来岩土工程领域研究的一个热点课题,在热能贮存、地热资源开发、核废料处置、供热管道设计、软土地基加固等工程领域有良好的应用背景。目前,国内外关于热固结问题已有一定程度的研究,但没有涉及到超固结土在温度荷载作用下的固结特性,以及温度荷载作用于土样引起的等效超固结比。因此,本文利用自行研制的热固结试验装置,在正常固结粉质黏土热特性研究的基础上,进一步展开了对超固结粉质黏土的试验研究,主要内容和创新工作如下：(1)测定了初始温度(250C)条件下饱和粉质黏土固结过程中的孔隙水压力的消散、土体内孔隙水的排出量和体应变的演化规律,围压分别设置为50kPa,100kPa,150kPa,200kPa。 (2)初始固结完成后,对土样进行升降温循环试验。不排水条件下进行升降温,温度等级分别为25℃—75℃以及75℃—25℃,温度稳定后进行排水固结,获得了饱和粉质黏土在整个温度循环过程中的孔隙水压力以及固结变形演变规律。 (3)在初始温度下,将围压升至指定压力值,完成初始固结。然后卸荷至指定围压值完成吸水固结过程,选用的超固结比分别为2、3、4。并按照上述(2)中的温度等级和试验内容对超固结土样进行升降温循环试验,获得了整个固结过程中试样孔隙水压力的消散和体应变的演化规律。 基于本文的试验结果,运用专业作图软件对数据进行拟合,对比不同超固结比土样的相关数据,分析了温度与围压作用于土样引起的超固结效应,得出了循环温度荷载作用于土样的等效超固结比。论文成果为饱和土热固结问题的深入研究奠定了良好的基础,也进一步丰富和完善了饱和土热固结问题的试验研究。
[Abstract]:The effect of temperature on mechanical properties of saturated clay is a hot topic in the field of geotechnical engineering in recent years, such as thermal energy storage, geothermal resource exploitation, nuclear waste disposal, heating pipeline design, and so on. Soft soil foundation reinforcement and other engineering fields have a good application background. At present, there have been some researches on the thermal consolidation problem at home and abroad, but the consolidation characteristics of the overconsolidated soil under the action of the temperature load and the equivalent overconsolidation ratio caused by the temperature load on the soil samples have not been involved in the case of the consolidation behavior of the overconsolidated soil under the action of the temperature load. Therefore, based on the study of thermal properties of normal consolidated silty clay, the experimental study of super-consolidated silty clay has been carried out in this paper by using a self-developed thermal consolidation test device, which is based on the study of thermal properties of normal consolidated silty clay. The main contents and innovations are as follows: (1) the dissipation of pore water pressure in the consolidation process of saturated silty clay at initial temperature (250C), the evolution of pore water discharge and volume strain in soil are measured. The confining pressure is set to 50 KPA, 100 KPA, 150 KPA, 200 KPA respectively. (2) after the initial consolidation is completed, the soil samples are subjected to the ascending and cooling cycle test. Under undrained conditions, the temperature grades are 25 鈩，
本文编号：2461636
[Abstract]:The effect of temperature on mechanical properties of saturated clay is a hot topic in the field of geotechnical engineering in recent years, such as thermal energy storage, geothermal resource exploitation, nuclear waste disposal, heating pipeline design, and so on. Soft soil foundation reinforcement and other engineering fields have a good application background. At present, there have been some researches on the thermal consolidation problem at home and abroad, but the consolidation characteristics of the overconsolidated soil under the action of the temperature load and the equivalent overconsolidation ratio caused by the temperature load on the soil samples have not been involved in the case of the consolidation behavior of the overconsolidated soil under the action of the temperature load. Therefore, based on the study of thermal properties of normal consolidated silty clay, the experimental study of super-consolidated silty clay has been carried out in this paper by using a self-developed thermal consolidation test device, which is based on the study of thermal properties of normal consolidated silty clay. The main contents and innovations are as follows: (1) the dissipation of pore water pressure in the consolidation process of saturated silty clay at initial temperature (250C), the evolution of pore water discharge and volume strain in soil are measured. The confining pressure is set to 50 KPA, 100 KPA, 150 KPA, 200 KPA respectively. (2) after the initial consolidation is completed, the soil samples are subjected to the ascending and cooling cycle test. Under undrained conditions, the temperature grades are 25 鈩，
本文编号：2461636
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