本文選題：軟土地基 + 長短樁復(fù)合地基　； 參考：《重慶交通大學(xué)》2014年碩士論文

【摘要】：隨著我國社會(huì)經(jīng)濟(jì)的迅速發(fā)展，人民對于基礎(chǔ)設(shè)施的要求也日益增高，尤其對于高等級(jí)公路的要求。在高速公路的建設(shè)中，我們難免遇到軟土、膨脹土、凍土等特殊地質(zhì)問題。而山區(qū)高速公路因?yàn)檐浲恋奶厥夥植迹瑥?fù)雜多樣的軟土特點(diǎn)，在處理軟土地基方面存在著一定的困難，用已有的軟土處理方法處理時(shí)往往打不到預(yù)期的效果。因此，研究山區(qū)高速公路軟土特性及處理方法稱為了一項(xiàng)重要的課題。 本論文依托貴州省交通廳科技項(xiàng)目——貴州山區(qū)高速公路軟基處理關(guān)鍵技術(shù)研究與示范工程，根據(jù)項(xiàng)目收集資料，進(jìn)行分析。從介紹軟土特點(diǎn)入手，著重介紹了貴州山區(qū)的軟土特點(diǎn)及現(xiàn)有的軟土路基處理方法。針對貴州山區(qū)軟土特點(diǎn)，本文選用長短樁復(fù)合地基方法來處理其軟土地基。 本文對于長短樁復(fù)合地基進(jìn)行了詳盡的分析。分別從長樁協(xié)力和長樁控沉兩個(gè)角度對其承載力進(jìn)行了研究，并提出了其安全系數(shù)的修正。根據(jù)兩種不同情況的承載力進(jìn)一步提出了沉降計(jì)算。 本文應(yīng)用PLAXIS有限元軟件，對影響長短樁復(fù)合地基穩(wěn)定性的影響因素一一做了分析，得出了以下結(jié)論： 1.CFG樁長的變化對長短樁復(fù)合地基沉降造成的影響較大，在臨界樁長范圍內(nèi)，CFG樁長的增加有利于控制復(fù)合地基的沉降。 2.水泥攪拌樁的樁長變化對于長短樁復(fù)合地基的沉降影響很小，但是水泥攪拌樁依然可以保證加固區(qū)土體具有一定的承載力，因此水泥攪拌樁依然有存在的必要性。 3.樁間距的變化會(huì)影響到樁身的附加應(yīng)力變化。 4.褥墊層厚度在一定范圍內(nèi)增加時(shí)，，CFG樁承受的應(yīng)力會(huì)相應(yīng)減小。 綜上所述，本文對影響長短樁處理山區(qū)高速公路軟土地基的影響因素做了詳盡的分析，對于貴州山區(qū)處理軟基方面有一定的現(xiàn)實(shí)意義，為指導(dǎo)工作提供依據(jù)。
[Abstract]:With the rapid development of our country's social economy, people's demand for infrastructure is increasing, especially for high grade highway. In the highway construction, we inevitably encounter soft soil, expansive soil, frozen soil and other special geological problems. However, due to the special distribution of soft soil and complex and diverse characteristics of soft soil, there are some difficulties in treating soft soil foundation in mountain expressway, and the expected effect is often not achieved when the existing soft soil treatment method is used. Therefore, the study of soft soil characteristics and treatment methods of expressway in mountainous area is an important subject. This paper relies on the key technology research and demonstration project of soft foundation treatment of Guizhou mountain expressway, which is a scientific and technological project of Guizhou Provincial Communications Department. According to the data collected from the project, it is analyzed. Starting with the introduction of the characteristics of soft soil, the paper emphatically introduces the characteristics of soft soil and the existing treatment methods of soft soil subgrade in Guizhou mountainous area. According to the characteristics of soft soil in Guizhou mountainous area, this paper chooses the method of long and short pile composite foundation to treat its soft soil foundation. In this paper, the long-long pile composite foundation is analyzed in detail. The bearing capacity of long pile is studied from the angle of long pile cooperation and long pile control settlement, and the modification of safety factor is put forward. The settlement calculation is further proposed according to the bearing capacity of two different cases. In this paper, the factors influencing the stability of long-long pile composite foundation are analyzed by using PLAXIS finite element software, and the following conclusions are obtained: The variation of 1.CFG pile length has a great influence on the settlement of long-long pile composite foundation, and the increase of pile length in the range of critical pile length is helpful to control the settlement of composite foundation. 2. The change of pile length of cement mixing pile has little influence on the settlement of long-long pile composite foundation, but cement mixing pile can still guarantee the bearing capacity of soil in the strengthened area, so the cement mixing pile still has the necessity to exist. 3. The change of pile spacing will affect the change of additional stress of pile body. 4. When the cushion thickness increases in a certain range, the stress of CFG pile will decrease accordingly. To sum up, this paper makes a detailed analysis of the factors affecting the treatment of soft soil foundation of expressway in mountainous areas with long and short piles, which has a certain practical significance for the treatment of soft foundation in mountainous areas of Guizhou, and provides the basis for guiding work.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U416.1

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本文編號(hào)：1789821