本文選題：涵洞 + ANSYS　； 參考：《太原理工大學》2014年碩士論文

【摘要】：涵洞廣泛的使用于鐵路、公路、水利、能源、市政和冶金等部門,它更是鐵路工程與公路工程的重要組成部分。研究涵洞土壓力變化規(guī)律對涵洞的施工建設有著重要的價值和意義。目前我國關于涵洞土壓力的研究并不完善,不同方法所計算的數(shù)值差別很大,于是導致施工中建筑材料的浪費,甚至有可能因不合理引發(fā)工程事故,嚴重的影響到我國涵洞的施工建設。隨著我國經濟的快速發(fā)展,涵洞的建設在工程施工中出現(xiàn)的越來越頻繁,確定涵洞土壓力的研究迫在眉睫。 本文利用ANSYS有限元軟件,對溝埋式箱涵的土壓力以及填土內部土拱效應進行模擬研究,分析了填土土拱效應與土壓力在不同條件下的變化規(guī)律,并且利用文獻中的模擬試驗所得結果與ANSYS模擬分析的數(shù)值對比分析。本文主要研究成果如下： 1.溝埋式箱涵(溝槽寬度為五倍的涵洞寬度)的垂直土壓力的最小值在涵頂?shù)闹行奈恢?隨著遠離涵頂中心,其垂直土壓力值逐漸增大,直至距涵洞的中軸線0.45D的位置時垂直土壓力達到最大值。側向土壓力的最大值在距離涵頂0.2D的位置附近,側向土壓力系數(shù)隨著填土高度的增加而減小。 2.在不考慮涵洞對土體的作用時,土體內部小主應力拱的形狀為一條懸鏈線,通過摩爾應力圓,分析土拱任意微分單元受力,根據(jù)其邊界條件得到溝埋式方涵在不考慮涵洞作用時小主應力拱的曲線方程,當摩擦角和摩擦系數(shù)增大,小主應力拱的曲率逐漸越小。根據(jù)小主應力拱曲線,進一步求出側土壓力系數(shù),土體豎向平均應力和水平側土壓力。 3.以等沉面和涵項平面為界限,將土拱的分布劃分為三個區(qū)域。 在區(qū)域Ⅰ內,隨著溝槽寬度的增大,土拱曲率逐漸減��；隨著內摩擦角的增大,土拱曲率逐漸減小；隨著溝槽與土體的摩擦系數(shù)的增大,土拱曲率逐漸減�。浑S著粘聚力的增大,土拱曲率逐漸增大。 在區(qū)域Ⅱ內,隨著溝槽寬度的增大,土拱曲率逐漸減��；隨著內摩擦角的增大,土拱曲率逐漸減小；隨著溝槽與土體的摩擦系數(shù)的增大,土拱曲率逐漸減小；隨著粘聚力的增大,土拱曲率逐漸增大。 在區(qū)域Ⅲ內,隨著溝槽寬度的不斷增加,內土柱內部的土拱效應明顯增強,土拱的曲率逐漸增大,在內土柱兩側的土體中,土拱的曲率隨著溝槽的寬度增加而不斷的減��；隨著土體的內摩擦角增大,內土柱內部的土拱曲率逐漸增大,而在內土柱兩側的土體內,土拱曲率隨著內摩擦角增大而減小；隨著溝槽與土體的摩擦系數(shù)增大,內土柱內部的土拱的曲率并無明顯變化,而內土柱外側土體內的土拱曲率隨著摩擦系數(shù)的增大而減小；隨著粘聚力的增大,內土柱內部土拱的曲率和內土柱外側土體內部的土拱曲率皆逐漸增大。 4.涵洞項板受壓產生形變,由撓度引起內土柱內部出現(xiàn)土拱效應。隨著涵洞頂板厚度的增大,涵頂土體內的土拱曲率逐漸減小。
[Abstract]:Culverts are widely used in railway, highway, water conservancy, energy, municipal and metallurgical sectors. It is of great value and significance to study the variation of soil pressure in culvert construction. At present, the research on soil pressure of culverts in China is not perfect, and the numerical value calculated by different methods is very different, which leads to the waste of construction materials in construction, and may even lead to engineering accidents because of unreasonable causes. Seriously affect the construction of culverts in China. With the rapid development of China's economy, the construction of culverts appears more and more frequently in engineering construction, so it is urgent to determine the earth pressure of culverts. In this paper, ANSYS finite element software is used to simulate the earth pressure and the soil arch effect of the box culvert, and the variation law of the soil arch effect and the earth pressure under different conditions are analyzed. The numerical results obtained from the simulation experiments in the literature are compared with those of the ANSYS simulation analysis. The main research results of this paper are as follows: 1. The minimum value of vertical earth pressure of the furrow buried box culvert (culvert width of five times the width of the culvert) is at the center of the culvert top. With the distance from the culvert top center, the vertical earth pressure value increases gradually. The vertical earth pressure reaches the maximum when it is 0.45D from the central axis of culvert. The maximum value of lateral earth pressure is about 0.2D from the culvert top, and the lateral earth pressure coefficient decreases with the increase of filling height. 2. Without considering the effect of culvert on soil, the shape of small principal stress arch in soil is a catenary line. According to the boundary conditions, the curve equation of the small principal stress arch is obtained when the culvert is not considered. When the friction angle and friction coefficient increase, the curvature of the small principal stress arch decreases gradually. According to the curve of small principal stress arch, the coefficient of lateral soil pressure, the vertical average stress of soil and the horizontal lateral earth pressure are obtained. 3. The distribution of soil arch is divided into three regions by the boundary of equal-settlement plane and culvert plane. In region I, the curvature of soil arch decreases with the increase of groove width, the curvature of soil arch decreases with the increase of internal friction angle, the curvature of soil arch decreases with the increase of friction coefficient between groove and soil. With the increase of cohesive force, the curvature of soil arch increases gradually. In region 鈪，

本文編號：1982763