發(fā)布時間：2019-04-20 13:13

【摘要】：溫度對飽和粘性土力學(xué)特性的影響是近年來巖土工程領(lǐng)域研究的一個熱點課題,在熱能貯存、地?zé)豳Y源開發(fā)、核廢料處置、供熱管道設(shè)計、軟土地基加固等工程領(lǐng)域有良好的應(yīng)用背景。目前,國內(nèi)外關(guān)于熱固結(jié)問題已有一定程度的研究,但沒有涉及到超固結(jié)土在溫度荷載作用下的固結(jié)特性,以及溫度荷載作用于土樣引起的等效超固結(jié)比。因此,本文利用自行研制的熱固結(jié)試驗裝置,在正常固結(jié)粉質(zhì)黏土熱特性研究的基礎(chǔ)上,進(jìn)一步展開了對超固結(jié)粉質(zhì)黏土的試驗研究,主要內(nèi)容和創(chuàng)新工作如下：(1)測定了初始溫度(250C)條件下飽和粉質(zhì)黏土固結(jié)過程中的孔隙水壓力的消散、土體內(nèi)孔隙水的排出量和體應(yīng)變的演化規(guī)律,圍壓分別設(shè)置為50kPa,100kPa,150kPa,200kPa。 (2)初始固結(jié)完成后,對土樣進(jìn)行升降溫循環(huán)試驗。不排水條件下進(jìn)行升降溫,溫度等級分別為25℃—75℃以及75℃—25℃,溫度穩(wěn)定后進(jìn)行排水固結(jié),獲得了飽和粉質(zhì)黏土在整個溫度循環(huán)過程中的孔隙水壓力以及固結(jié)變形演變規(guī)律。 (3)在初始溫度下,將圍壓升至指定壓力值,完成初始固結(jié)。然后卸荷至指定圍壓值完成吸水固結(jié)過程,選用的超固結(jié)比分別為2、3、4。并按照上述(2)中的溫度等級和試驗內(nèi)容對超固結(jié)土樣進(jìn)行升降溫循環(huán)試驗,獲得了整個固結(jié)過程中試樣孔隙水壓力的消散和體應(yīng)變的演化規(guī)律。 基于本文的試驗結(jié)果,運用專業(yè)作圖軟件對數(shù)據(jù)進(jìn)行擬合,對比不同超固結(jié)比土樣的相關(guān)數(shù)據(jù),分析了溫度與圍壓作用于土樣引起的超固結(jié)效應(yīng),得出了循環(huán)溫度荷載作用于土樣的等效超固結(jié)比。論文成果為飽和土熱固結(jié)問題的深入研究奠定了良好的基礎(chǔ),也進(jìn)一步豐富和完善了飽和土熱固結(jié)問題的試驗研究。
[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，

本文編號：2461636