【摘要】：巖溶地區(qū)的樁需要考慮溶洞對樁穩(wěn)定性的影響。溶洞對垂直承載樁的穩(wěn)定性影響研究已開展過較多的研究工作,而溶洞對水平承載樁的穩(wěn)定性影響研究在國內(nèi)外還沒有開展過。本文選擇周邊有溶洞存在的基坑支護(hù)樁為研究對象,運(yùn)用數(shù)值分析的方法研究溶洞對支護(hù)樁的穩(wěn)定性影響。按照溶洞和支護(hù)樁的相對位置,將巖溶地區(qū)支護(hù)樁與溶洞的受力分析模型分成三種,第一種模型為溶洞位于支護(hù)樁的下方；第二種模型為溶洞位于支護(hù)樁的主動區(qū)；第三種模型為溶洞位于支護(hù)樁的被動區(qū)。通過數(shù)值計算,分析在溶洞的大小形態(tài)、溶洞與樁的相對位置、樁的嵌固端深度、樁長、樁徑、上覆土層厚度及基坑開挖深度等因素影響下,溶洞對支護(hù)樁穩(wěn)定性的影響。每種計算模型又按上覆土層厚度的大小分成5個亞類,每個亞類的力學(xué)分析參數(shù)取值按正交試驗方法進(jìn)行設(shè)計,通過建立溶洞影響穩(wěn)定性判據(jù)求出溶洞到支護(hù)樁的臨界安全距離。通過計算發(fā)現(xiàn),土層厚度較薄時溶洞對支護(hù)樁沒有影響,當(dāng)土層厚度較厚時溶洞對支護(hù)樁有影響,并對有影響的部分進(jìn)行了多元線性回歸,求出了臨界安全距離和各影響因素之間的數(shù)學(xué)表達(dá)式,并用工程實(shí)例進(jìn)行了驗證。研究成果為解決巖溶地區(qū)支護(hù)樁的穩(wěn)定性分析的問題并編制有關(guān)規(guī)范的相關(guān)條文提供了基礎(chǔ)性技術(shù)依據(jù)。
[Abstract]:The influence of karst cave on pile stability should be considered in karst area. The influence of cavern on the stability of vertical bearing pile has been studied, but the influence of cave on the stability of horizontal bearing pile has not been carried out at home and abroad. In this paper, the influence of karst cave on the stability of supporting pile is studied by numerical analysis. According to the relative position of karst cave and supporting pile, the stress analysis model of supporting pile and karst cave in karst area is divided into three kinds: the first model is that the cave is located under the supporting pile, the second model is located in the active zone of supporting pile. The third model is that the cave is located in the passive zone of the supporting pile. Through numerical calculation, the influence of karst cave on the stability of supporting pile is analyzed under the influence of the size and shape of the cave, the relative position of the cave to the pile, the depth of the embedded end, the length of the pile, the diameter of the pile, the thickness of the overlying soil layer and the excavation depth of the foundation pit. Each model is divided into five subclasses according to the thickness of the overlying soil, and the mechanical analysis parameters of each subclass are designed by orthogonal test method. The critical safety distance from the cavern to the supporting pile is obtained by establishing the stability criterion of the cavern. Through calculation, it is found that the cavern has no influence on the supporting pile when the soil thickness is thinner, and the cavern has influence on the supporting pile when the soil layer is thicker, and carries on the multivariate linear regression to the affected part. The mathematical expressions between the critical safety distance and the influencing factors are obtained and verified by an engineering example. The research results provide a basic technical basis for solving the stability analysis of supporting piles in karst areas and compiling relevant provisions of relevant codes.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU473.1

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相關(guān)期刊論文 前1條

1 李大通,羅雁;中國碳酸鹽巖分布面積測量[J];中國巖溶;1983年02期

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本文編號：2280781