【摘要】：隨著國民經(jīng)濟(jì)快速發(fā)展,我國多個(gè)地區(qū)地下水資源遭到過量開采,導(dǎo)致了嚴(yán)重的地面沉降,而不均勻沉降又誘發(fā)了大量地裂縫,造成了嚴(yán)重的環(huán)境問題和重大的經(jīng)濟(jì)財(cái)產(chǎn)損失。因此,深入研究考慮三維地質(zhì)結(jié)構(gòu)的土體不均沉降與地裂縫的成災(zāi)機(jī)理和發(fā)育過程具有十分重要的科學(xué)價(jià)值和實(shí)際意義。本文以蘇錫常地區(qū)地裂縫為研究背景,對(duì)基底起伏(潛山)和斷裂構(gòu)造發(fā)育的厚層不均勻軟粘土差異沉降引起的土體裂縫的演化特征進(jìn)行了試驗(yàn)研究,通過電位、電流、視電阻率、滲流和變形等信息的監(jiān)測對(duì)地裂縫發(fā)育演化的動(dòng)態(tài)過程進(jìn)行了分析。無錫市錫北鎮(zhèn)光明村地裂縫位于新華夏第二隆起帶和秦嶺東西向復(fù)雜構(gòu)造帶的交接部位,存在著多條平行的由南向北傾斜的基底隆起構(gòu)造,基巖面起伏較大�，F(xiàn)場地質(zhì)調(diào)查和室內(nèi)分析均表明該地裂縫主要發(fā)育在基巖隆起區(qū)和基巖面形態(tài)變化較大的區(qū)域,基底構(gòu)造對(duì)地裂縫的形成和演化有著顯著的控制性影響�；坠铝撋脚c梁式起伏的土體失水開裂試驗(yàn)表明:土體失水開裂過程可劃分為開裂前I、快速開裂II和開裂停滯III三個(gè)階段;裂縫的發(fā)育演化受模型邊界和基底起伏的顯著影響,在快速開裂II-1階段,裂縫主要發(fā)育在模型邊界部位,II-2階段,裂縫主要在基底起伏影響范圍內(nèi)發(fā)育,在III階段,盡管土體表面開裂仍在發(fā)生,裂縫發(fā)育的整體格局已經(jīng)不再發(fā)生顯著變化;從裂縫形態(tài)看,后期裂縫主要與前期裂縫垂直相交,特別是在基底起伏范圍內(nèi)和模型邊界區(qū)域�；诰W(wǎng)絡(luò)分布式并行電法,對(duì)土體開裂的動(dòng)態(tài)過程進(jìn)行了反演分析,反演結(jié)果與觀察結(jié)果吻合較好。以無錫市錫北鎮(zhèn)光明村地裂縫為工程背景進(jìn)行了土體不均勻沉降誘導(dǎo)的地裂縫試驗(yàn),在對(duì)試驗(yàn)?zāi)Ｐ椭胁煌课煌馏w的地電響應(yīng)特征(自然電位、一次場電位、激勵(lì)電流、視電阻率)和表面沉降位移監(jiān)測的基礎(chǔ)上,通過分析不均勻沉降與地裂縫發(fā)育演化特征獲得了以下認(rèn)識(shí):土體中電位、電流和電阻率的變化與土體含水量密切相關(guān),隨著土體中含水量的改變,自然電位、一次場電位、激勵(lì)電流和視電阻率發(fā)生急劇變化;不均勻沉降導(dǎo)致土體中裂縫的產(chǎn)生,NDPGES反演信息和沉降觀測值均表明在曲線曲率值較大位置容易產(chǎn)生不均勻沉降和裂縫,不均勻沉降的程度越大,地裂縫的長度、寬度、深度也會(huì)越大。
[Abstract]:With the rapid development of the national economy, groundwater resources in many regions of China have been overexploited, resulting in serious land subsidence, but uneven settlement has induced a large number of ground cracks, resulting in serious environmental problems and significant economic property losses. Therefore, it is of great scientific value and practical significance to deeply study the mechanism and development process of the formation and development of the uneven settlement of soil and the ground fissures considering the three-dimensional geological structure. In this paper, based on the background of ground fissures in Suxi-Chang area, the evolution characteristics of soil cracks caused by uneven differential settlement of thick layer soft clay developed in the basement undulation (buried hill) and faulted structures are studied experimentally. The monitoring of apparent resistivity, seepage and deformation is used to analyze the dynamic process of ground fracture development and evolution. The ground fissures in Guangming Village, Xibei Town, Wuxi City, are located at the junction of the second uplift zone of Xinhuaxia and the complex tectonic belt of the east west direction of Qinling Mountains. There are many parallel basement uplift structures inclined from south to north, and the bedrock surface is fluctuating greatly. Field geological investigation and laboratory analysis show that the cracks in this area are mainly developed in the bedrock uplift area and the area where the bedrock surface morphology changes greatly, and the basement structure has a significant controlling effect on the formation and evolution of the ground fracture. The tests of soil water loss cracking in isolated buried-hill and beam undulating soil show that the process of soil water-loss cracking can be divided into three stages: I before cracking, II with rapid cracking and III with stagnant cracking. The evolution of fractures is significantly affected by the model boundary and basement fluctuation. In the rapid cracking II-1 stage, the fractures mainly develop in the model boundary, in the II-2 stage, in the basement undulation range, and in the III stage. Although the surface cracking of soil is still taking place, the overall pattern of crack development has not changed significantly. From the point of view of fracture morphology, the late fracture mainly intersects vertically with the early fracture, especially in the range of basement fluctuation and the boundary area of the model. Based on the network distributed parallel electrical method, the dynamic process of soil cracking is inversed and analyzed, and the inversion results are in good agreement with the observed results. Based on the ground fissures in Guangming Village, Xibei Town, Wuxi City, the ground fissures induced by uneven settlement of soil were tested. The geoelectric response characteristics (natural potential, primary field potential, excitation current) of different parts of soil in the test model were studied. On the basis of apparent resistivity) and surface subsidence displacement monitoring, the following conclusions are obtained by analyzing the characteristics of uneven settlement and evolution of ground fissures: the changes of potential, current and resistivity in soil are closely related to soil water content. With the change of soil moisture content, the natural potential, primary field potential, excitation current and apparent resistivity change sharply. NDPGES inversion information and settlement observations indicate that uneven settlement and cracks are easy to occur in the larger curvilinear curvature. The greater the degree of uneven settlement, the longer the length and width of the ground crack. The greater the depth, too.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P642.26

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 姜規(guī)模;西安市地面沉降與地裂縫研究[J];城市勘測;2005年03期

2 耿大玉,李忠生;中美兩國的地裂縫災(zāi)害[J];地震學(xué)報(bào);2000年04期

3 楊獻(xiàn)忠,陳敬中,葉念軍;論蒙脫石的脫水作用及其對(duì)地面沉降的影響[J];資源調(diào)查與環(huán)境;2003年02期

4 薛禹群;地下水資源與江蘇地面沉降研究[J];江蘇地質(zhì);2001年04期

5 伍洲云,余勤,張?jiān)?蘇錫常地區(qū)地裂縫形成過程[J];水文地質(zhì)工程地質(zhì);2003年01期

6 武強(qiáng),陳佩佩;地裂縫災(zāi)害研究現(xiàn)狀與展望[J];中國地質(zhì)災(zāi)害與防治學(xué)報(bào);2003年01期

，

本文編號(hào)：2385301