【摘要】：論文以有限元軟件Midas GTS和有限差分軟件FLAC3D作為主要平臺,利用FLAC3D和Midas建立土與地下結(jié)構(gòu)相互作用的模型。之后通過FLAC3D進行計算,分別就含水率和地下水位改變對地下結(jié)構(gòu)及土體的地震反應的影響進行了探討。最后對在可液化場地下不同因素對地下結(jié)構(gòu)動力響應的影響進行了研究,主要的研究成果如下:1.論文的第一部分闡述了含水率對土體的彈性模量、黏聚力、內(nèi)摩擦角以及土體密度的影響。發(fā)現(xiàn)密實度一定的情況下,黏性土的多種力學參數(shù)會隨著最佳含水率的出現(xiàn)而出現(xiàn)“峰值”效應。本部分利用FLAC3D差分軟件對不飽和土在地震作用下的動力響應進行了模擬和分析,探討了土中含水率對于地下結(jié)構(gòu)地震動力響應的影響規(guī)律。結(jié)果表明:(1)在最佳含水率附近,土層的性質(zhì)對于土與地下結(jié)構(gòu)的作用來說是最良好的,此時結(jié)構(gòu)的內(nèi)力可取得最小值;(2)頂板和底板的相對水平位移變化不大,并且在最佳含水率之前位移的數(shù)值隨著含水率的增加而逐漸減小;(3)土體和結(jié)構(gòu)的加速度峰值都隨著含水率的增加而呈減小的趨勢。2.論文的第二部分利用FLAC3D軟件,把土與地下結(jié)構(gòu)的相互作用問題視為平面應變問題,采用Mohr-Coulomb本構(gòu)模型和Finn本構(gòu)模型分別來描述處于水位線上、下土體的非線性動力特性和孔隙壓力的發(fā)展規(guī)律,對地震作用下土與地下結(jié)構(gòu)的相互作用不同工況進行了數(shù)值模擬。結(jié)果表明:(1)水位線上升,孔隙壓力大幅度提高,孔壓比增加,結(jié)構(gòu)周圍土體更容易發(fā)生液化;(2)上下板和中柱的加速度峰值產(chǎn)生時刻與地震波峰值產(chǎn)生的時刻相同,而且水位變化對上下板和中柱的加速度影響不明顯;(3)底板兩角隅處的應力大于中柱的應力,并且底板的主應力都隨著地下水位的提升而增大。3.論文的第三部分就三個影響因素:對不同結(jié)構(gòu)截面形式、水平-豎向波共同作用、不同地震波輸入對地下結(jié)構(gòu)的動力響應的影響進行了研究,結(jié)果如下:(1)確定了在地震作用下處于可液化場地的拱形結(jié)構(gòu)和矩形結(jié)構(gòu)的應力的分布和最不利受力位置;(2)模型分別在豎向地震波以及橫向地震波單獨和共同作用下,孔壓比幅值也不相同,總體來講,水平和豎向波共同作用下的孔壓比更大一些;(3)峰值不同的地震波對結(jié)構(gòu)的應力的分布影響不大,卻對結(jié)構(gòu)加速度影響十分顯著。4.論文的第四部分,對本文的研究成果進行了總結(jié),指出了需要進一步研究的問題,并且建議了改進思路和方法。
[Abstract]:In this paper, the finite element software Midas GTS and the finite difference software FLAC3D are used as the main platforms to establish the model of the interaction between soil and underground structure by using FLAC3D and Midas. Then the effects of water content and groundwater level on the seismic response of underground structure and soil are discussed by FLAC3D calculation. Finally, the effects of different factors on the dynamic response of underground structures under liquefied sites are studied. The main research results are as follows: 1. In the first part of the paper, the effects of moisture content on elastic modulus, cohesion, internal friction angle and soil density are described. It is found that under the condition of certain compactness, a variety of mechanical parameters of clay will appear "peak" effect with the appearance of optimal moisture content. In this part, the dynamic response of saturated soil under earthquake is simulated and analyzed by using FLAC3D difference software, and the influence of soil moisture content on seismic dynamic response of underground structure is discussed. The results show that: (1) near the optimum moisture content, the properties of soil layer are the best for the action of soil and underground structure, and the internal force of the structure can obtain the minimum value at this time; (2) the relative horizontal displacement of roof and floor does not change much, and the value of displacement decreases with the increase of moisture content before the optimum moisture content; (3) the peak acceleration of soil and structure decreases with the increase of moisture content. 2. In the second part of the paper, the interaction between soil and underground structure is regarded as a plane strain problem by using FLAC3D software, and the Mohr-Coulomb Constitutive Model and Finn Constitutive Model are used to describe the interaction between soil and underground structure on the water level line, respectively. The nonlinear dynamic characteristics of soil and the development of pore pressure are studied by numerical simulation of the interaction between soil and underground structure under earthquake. The results show that: (1) when the water level line rises, the pore pressure increases greatly, and the pore pressure ratio increases, the soil around the structure is more prone to liquefaction; (2) the peak acceleration time of upper and lower plate and middle column is the same as that of seismic wave, and the influence of water level change on the acceleration of upper and lower plate and middle column is not obvious; (3) the stress at the corner of the bottom plate is greater than that of the middle column, and the principal stress of the floor increases with the increase of groundwater level. In the third part of the paper, three influencing factors are studied: the interaction of different structural sections, horizontal and vertical waves, and the influence of different seismic wave inputs on the dynamic response of underground structures. The results are as follows: (1) the stress distribution and the most unfavorable stress position of arch structure and rectangular structure in liquefaction site under earthquake action are determined. (2) under the action of vertical seismic wave and transverse seismic wave, the amplitude of pore pressure ratio is different, and the pore pressure ratio is larger under the combined action of horizontal and vertical waves. (3) the seismic waves with different peaks have little effect on the stress distribution of the structure, but have a significant effect on the acceleration of the structure. 4. In the fourth part of the paper, the research results are summarized, the problems that need to be further studied are pointed out, and the improvement ideas and methods are suggested.
【學位授予單位】：北京建筑大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU435

【參考文獻】

相關期刊論文 前10條

1 鄭永來,劉曙光,楊林德,童峰;軟土中地鐵區(qū)間隧道抗震設計研究[J];地下空間;2003年02期

2 林家浩;非平穩(wěn)隨機地震響應的精確高效算法[J];地震工程與工程振動;1993年01期

3 陳波,呂西林,李培振,陳躍慶;用ANSYS模擬結(jié)構(gòu)-地基動力相互作用振動臺試驗的建模方法[J];地震工程與工程振動;2002年01期

4 林利民;陳健云;;軟土中淺埋地鐵車站結(jié)構(gòu)的抗震性能分析[J];防災減災工程學報;2006年03期

5 張艷美;張旭東;;飽和砂土地基三維地震響應分析[J];工程抗震與加固改造;2007年05期

6 徐艷玲;唐伯明;謝國棟;朱洪洲;;不同含水率下應力級位對粘性土動回彈模量的影響[J];中外公路;2011年06期

7 蘇濤;;探討框架式地下建筑結(jié)構(gòu)的抗震性能[J];低碳世界;2014年07期

8 陳國興;左熹;王志華;杜修力;周恩全;;可液化場地地鐵車站結(jié)構(gòu)地震破壞特性振動臺試驗研究[J];建筑結(jié)構(gòu)學報;2012年01期

9 常立君;張吾渝;馬艷霞;;非飽和土抗剪強度與含水率的關系研究[J];山西建筑;2012年22期

10 崔圣龍;劉艷梅;楊國強;;液化場地土—結(jié)構(gòu)相互作用試驗參數(shù)識別綜述[J];山西建筑;2010年04期

相關碩士學位論文 前1條

1 豐彪;基于PC機的視景仿真技術與房屋震害演示系統(tǒng)[D];中國地震局工程力學研究所;2003年

，

本文編號：2488704