本文選題：基坑 + 圍護結(jié)構(gòu)��； 參考：《浙江大學(xué)》2015年博士論文

【摘要】：隨著城市化進程的加快以及對城市空間利用要求的不斷提高,目前的基坑工程也呈現(xiàn)出一些新的問題,基坑工程呈現(xiàn)出開挖規(guī)模大、挖深大以及基坑周圍環(huán)境復(fù)雜的特點。為了更好的控制周圍既有設(shè)施的安全,對地下開挖工程的圍護結(jié)構(gòu)變形的要求也越來越高。同時,對基坑開挖引起的周圍設(shè)施的變形預(yù)測以及保護措施的研究也具有重要的現(xiàn)實意義。 本文結(jié)合杭州地區(qū)的現(xiàn)場試驗、數(shù)值模擬以及理論分析對基坑工程的變形特性以及基坑開挖對周圍既有設(shè)施的變形影響進行了分析,主要研究工作及創(chuàng)新成果如下： 1、對軟土地區(qū)常見的三種基坑圍護結(jié)構(gòu)：排樁加止水帷幕結(jié)合內(nèi)支撐圍護結(jié)構(gòu)、SwM工法樁結(jié)合內(nèi)支撐圍護結(jié)構(gòu)、地下連續(xù)墻結(jié)合內(nèi)支撐圍護結(jié)構(gòu)的側(cè)向位移、樁(墻)后地表沉降、深層土體沉降等變形特性進行了對比分析,分析表明不同類型圍護結(jié)構(gòu)的側(cè)向變形以及土體沉降變化趨勢較為接近,而圍護結(jié)構(gòu)的系統(tǒng)剛度對圍護結(jié)構(gòu)及周圍土體的變形值影響較大。 2、嵌巖連續(xù)墻由于端部處于強度較高的巖層中,其圍護性狀不同于連續(xù)墻端部處于土層時的圍護性狀。通過對嵌巖連續(xù)墻和非嵌巖連續(xù)墻的側(cè)向位移、豎向位移、支撐軸力等監(jiān)測資料的分析對比發(fā)現(xiàn),嵌巖部分連續(xù)墻的最大側(cè)向位移小于非嵌巖部分連續(xù)墻的最大側(cè)向位移。隨著連續(xù)墻系統(tǒng)剛度的提高,墻身側(cè)向位移呈減小的趨勢,嵌巖部分連續(xù)墻最大側(cè)向位移的減小幅度小于非嵌巖部分側(cè)向位移的減小幅度。非嵌巖連續(xù)墻在第一道混凝土支撐和第四道鋼支撐上的支撐軸力要遠(yuǎn)大于嵌巖連續(xù)墻,且支撐軸力總和比非嵌巖連續(xù)墻大44.9%。 3、結(jié)合一雙排微型樁的現(xiàn)場試驗,分析了雙排微型樁圍護結(jié)構(gòu)控制變形的作用機理。后排樁所受主動土壓力、基坑底部所受被動區(qū)土壓力和樁身位移有關(guān),被動區(qū)的實測土壓力和彈性地基梁法計算值比較接近。 4、具有內(nèi)支撐圍護結(jié)構(gòu)的系統(tǒng)在基坑邊角處具有更大的系統(tǒng)剛度,使得基坑邊角附近處土體的位移小于距離邊角較遠(yuǎn)處土體的位移,即基坑的變形問題表現(xiàn)出三維特性。通過對不同類型圍護結(jié)構(gòu)現(xiàn)場監(jiān)測資料的分析發(fā)現(xiàn),不同類型圍護結(jié)構(gòu)變形及周圍土體沉降的三維效應(yīng)有所不同,土體沉降和側(cè)向位移的三維效應(yīng)有一定的相關(guān)性。 5、根據(jù)圍護結(jié)構(gòu)周圍土體變形的特點,給出了建筑沉降的計算方法并結(jié)合實測結(jié)果進行了對比驗證。同時,根據(jù)實測資料,分別分析了基坑開挖引起的建筑沉降、管道沉降的變形特點,并給出了管道、建筑沉降與地表沉降的關(guān)系。 6、通過數(shù)值模擬分析提出了周圍受荷樁基存在時的土體側(cè)向位移及土體沉降規(guī)律的簡化計算方法。同時對樁間距及承臺間距等參數(shù)對土體沉降及側(cè)向位移的影響進行了分析,分析結(jié)果表明,受荷樁的存在導(dǎo)致樁周的土體側(cè)向位移變大,增加系數(shù)為1.0-1.3倍；土體沉降會有一定程度的減小,折減系數(shù)可以根據(jù)經(jīng)驗公式求得。本文也對基坑開挖引起的土體沉降對既有受荷樁基側(cè)阻及端阻的影響進行了分析,并分別提出了適合于摩擦樁及端承樁的建筑沉降簡化計算方法并與工程實測數(shù)據(jù)進行了驗證。同時,也提出了基坑開挖引起的建筑側(cè)向位移的計算方法。
[Abstract]:Along with the acceleration of urbanization and the increasing demand for urban space utilization , the foundation pit engineering presents some new problems . The foundation pit engineering has the characteristics of large excavation scale , large excavation depth and complex surrounding environment . In order to better control the safety of existing facilities around the foundation pit , the requirements for deformation of surrounding structures of underground excavation engineering are also higher and higher . At the same time , the research on deformation prediction and protective measures of surrounding facilities caused by excavation of foundation pit also has important practical significance .

Based on the field test , numerical simulation and theoretical analysis of Hangzhou area , the deformation characteristics of foundation pit engineering and the influence of foundation pit excavation on the deformation of existing facilities around the foundation pit are analyzed . The main research work and innovation results are as follows :

1 . Three kinds of foundation pit enclosure structures common in soft soil area are as follows : pile row and water stop curtain combined with inner support enclosing structure , SwM working method pile combined with inner support enclosing structure , lateral displacement of pile ( wall ) , surface settlement after pile ( wall ) and settlement of deep soil , etc . The analysis shows that the lateral deformation of different types of surrounding structures and the tendency of settlement of soil mass are close to each other , and the system rigidity of enclosure structure has great influence on the surrounding structure and the deformation value of surrounding soil .

2 . In the rock - socketed continuous wall , the maximum lateral displacement of the continuous wall of the rock - socketed part is less than the maximum lateral displacement of the continuous wall of the non - socketed part because the end part is in the rock stratum with higher strength , and the maximum lateral displacement of the continuous wall of the rock - socketed part is less than the maximum lateral displacement of the discontinuous wall of the non - socketed part .

3 . Combined with the on - site test of a double - row micro - pile , the mechanism of controlling deformation of the double - row micro - pile enclosure structure is analyzed . The active earth pressure of the rear row pile , the soil pressure at the bottom of the foundation pit and the displacement of the pile body are concerned , and the measured soil pressure in the passive area is close to the calculated value of the elastic foundation beam method .

4 . The system with built - in support structure has greater system rigidity at the corner of the foundation pit , so that the displacement of the soil around the corner of the foundation pit is less than the displacement of the soil around the boundary angle , that is , the deformation problem of the foundation pit shows the three - dimensional characteristic . Through the analysis of the field monitoring data of different types of enclosure structures , the three - dimensional effect of deformation of different types of enclosure structures and settlement of surrounding soil is different , and the three - dimensional effect of settlement and lateral displacement of the soil has a certain correlation .

5 . According to the characteristics of the deformation of the soil around the surrounding structure , the calculation method of the building settlement is given and compared with the measured results . At the same time , according to the measured data , the deformation characteristics of the settlement and the settlement of the pipeline caused by the excavation of the foundation pit are analyzed , and the relation between the settlement of the pipeline and the surface subsidence is given .

6 . A simplified calculation method for the lateral displacement of soil and the rule of settlement of soil mass is presented by numerical simulation analysis . The influence of pile spacing and spacing of bearing platform on settlement and lateral displacement of soil mass is analyzed . The results show that the lateral displacement of soil body caused by the existence of pile is 1.0 - 1.3 times .
The settlement of soil mass can be reduced to some extent , and the reduction coefficient can be obtained according to the empirical formula . In this paper , the influence of settlement of soil mass caused by excavation of foundation pit on both side resistance and end resistance of the existing pile foundation is analyzed , and the simplified calculation method of building settlement suitable for friction pile and end - bearing pile is also presented .
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TU473

【參考文獻】

相關(guān)期刊論文 前10條

1 王軍,吳君侯,吳恩,章宇;上海深基坑工程設(shè)計與施工的問題與對策[J];地下空間與工程學(xué)報;2005年04期

2 王衛(wèi)東,吳江斌,黃紹銘;上海地區(qū)建筑基坑工程的新進展與特點[J];地下空間與工程學(xué)報;2005年04期

3 王浩然;王衛(wèi)東;徐中華;;基坑開挖對鄰近建筑物影響的三維有限元分析[J];地下空間與工程學(xué)報;2009年S2期

4 劉建航;;地下墻深基坑周圍地層移動的預(yù)測和治理之二——基坑周圍地層移動的預(yù)測[J];地下工程與隧道;1993年02期

5 劉建航,劉國彬,范益群;軟土基坑工程中時空效應(yīng)理論與實踐(上)[J];地下工程與隧道;1999年03期

6 姚京華;軟地基的不均勻沉降引起建筑物傾斜的原因分析及加固糾偏處理[J];安徽建筑;2003年03期

7 邢恩橋,許國輝,楊俊杰;用靜力觸探參數(shù)確定地基土水平地基抗力系數(shù)的比例系數(shù)m值——以天津地區(qū)為例[J];中國海洋大學(xué)學(xué)報(自然科學(xué)版);2005年04期

8 侯學(xué)淵,劉國彬,黃院雄;城市基坑工程發(fā)展的幾點看法[J];施工技術(shù);2000年01期

9 宓群;趙建忠;蔡建榮;;嵌巖地下連續(xù)墻沖孔槽段施工新工藝[J];施工技術(shù);2008年S2期

10 王景廷;施工降水造成鄰近建筑物不均勻沉降一例[J];土工基礎(chǔ);1998年02期

相關(guān)博士學(xué)位論文 前2條

1 李志高;地下綜合體深基坑施工環(huán)境影響及保護研究[D];同濟大學(xué);2006年

2 張乾青;軟土地基樁基受力性狀和沉降特性試驗與理論研究[D];浙江大學(xué);2012年

，

本文編號：2002507