【摘要】：花崗巖殘積土是指花崗巖經風化后未被搬運而殘留于原地的碎屑物質組成的土體,主要由石英、長石、方解石等粗顆粒礦物和高嶺土為主的粘性土礦物組成。其原巖結構完全被破壞,可用手剝下及手指捻碎,過去我國一直將其作為粘性土來看待。但由于其云母含量高,結構松散,水穩性差,粘結力小,碾壓成型困難,因此在公路中的應用受到限制。通平高速公路1標至7標(K1+000-K42+500)分布著大量的花崗巖殘積土,若采用棄土借方的方案,無論從經濟還是環保角度來說都不可取,為保證通平高速公路花崗巖殘積土路基的穩定性和耐久性,本文通過對花崗巖殘積土進行室內試驗、現場碾壓試驗、彎沉檢測和沉降觀測,系統的研究了花崗巖殘積土路基填筑技術。取得的主要成果如下：(1)通過室內土工試驗,全面了解了通平高速花崗巖殘積土的工程性質；根據花崗巖殘積土的工程性質及填筑路基的不同部位,提出了不同的處理方法；根據試驗路段填料性能的研究,得出花崗巖殘積土的壓實控制標準。(2)研究了水泥改良土的加固機理；通過試驗研究表明,水泥能夠明顯改善花崗巖殘積土的物理性質和力學性質；根據改良土的7天浸水抗壓強度來確定水泥摻量,提出了路基不同部位的改良土抗壓強度要求和水泥摻量,并提出不同路段的水泥改良土的施工方案。(3)研究花崗巖殘積土的壓實機理,通過試驗路段的修筑,提出了花崗巖殘積土填筑路基的最佳碾壓工藝。(4)通過彎沉檢測和沉降觀測數據可知花崗巖殘積土填筑的路基穩定性比較好。
[Abstract]:Granite residual soil refers to the soil composed of clastic material which is not transported after weathering and remains in situ. It is mainly composed of coarse granular minerals such as quartz feldspar calcite and clay minerals dominated by kaolin. The original rock structure is completely destroyed, which can be stripped off by hand and broken by fingers, which has been regarded as clay in China in the past. However, its application in highway is limited because of its high content of mica, loose structure, poor water stability, low adhesion and difficult compaction. In Tongping Expressway (K1 000-K42 500), there is a large amount of granite residual soil distributed in K1 000-K42 500, so it is not advisable to adopt the scheme of abandoned soil debit, either from an economic or an environmental point of view. In order to ensure the stability and durability of granite residual soil subgrade of Tongping Expressway, this paper carries out laboratory test, field rolling test, deflection detection and settlement observation of granite residual soil. The filling technology of granite residual soil subgrade is studied systematically. The main achievements are as follows: (1) through the laboratory geotechnical tests, the engineering properties of Tongping high speed granite residual soil are fully understood, and different treatment methods are put forward according to the engineering properties of granite residual soil and different parts of embankment. According to the research of filling performance of test section, the compaction control standard of granite residual soil is obtained. (2) the reinforcement mechanism of cement modified soil is studied, and the experimental results show that, Cement can obviously improve the physical and mechanical properties of granite residual soil, determine the cement content according to the 7 days soaking compressive strength of the improved soil, and put forward the compressive strength requirements and cement content of the improved soil in different parts of the roadbed. And put forward the construction plan of cement improved soil in different sections. (3) study the compaction mechanism of granite residual soil, through the construction of test section, The best compaction technology for subgrade filling with granite residual soil is put forward. (4) the stability of embankment filled with granite residual soil is better than that of granite residual soil by means of deflection detection and settlement observation data.
【學位授予單位】：長沙理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U416.1
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本文編號：2263045