本文選題：微型樁　切入點(diǎn)：淺層堆積層滑坡　出處：《西安工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：我國所有類型質(zhì)災(zāi)害中,滑坡比例高達(dá)50%以上。陜西省境內(nèi)滑坡在各種質(zhì)災(zāi)害中更是達(dá)到了62.3%比重,而淺層堆積層滑坡在各種類型滑坡中達(dá)到了65%,因而開展針對(duì)淺層堆積層滑坡加固防止技術(shù)有著重大實(shí)際意義。隨著滑坡災(zāi)害加固技術(shù)發(fā)展,微型樁因非開挖施工、對(duì)樁身周圍土體擾動(dòng)較小、樁布設(shè)位置靈活,施工速度快和良好經(jīng)濟(jì)性等特點(diǎn),近年來在淺層堆積層滑坡中應(yīng)用越來越多。但微型樁加固滑坡理論研究遠(yuǎn)遠(yuǎn)滯后于微型樁在加固滑坡實(shí)際工程中使用情況。本文針對(duì)這種現(xiàn)狀,以相似原理為理論依據(jù),以框架模型試驗(yàn)為研究手段,對(duì)微型樁加固淺層堆積層坡過程中樁身應(yīng)力分布規(guī)律進(jìn)行研究。試驗(yàn)中通過對(duì)單排樁、雙排樁、梅花形布設(shè)三排微型樁加固淺層堆積層滑坡進(jìn)行試驗(yàn),探究合理樁間距、排間距以及微型樁樁頂布設(shè)連系梁條件,微型樁在抗滑過程中樁身應(yīng)力分布規(guī)律。通過對(duì)5組模型試驗(yàn)實(shí)驗(yàn)數(shù)據(jù)分析,主要得到以下結(jié)論：(1)未布設(shè)微型樁時(shí),坡頂加載5.6kpa后,滑坡就達(dá)到失穩(wěn)破壞臨界階段,而合理布樁方式三排樁試驗(yàn)中,滑坡達(dá)到失穩(wěn)破壞臨滑階段,坡頂需要施加24.7kpa,由此可以看出微型樁對(duì)滑坡穩(wěn)定程度提高是非常明顯,微型樁應(yīng)用于淺層堆積層滑坡加固治理工程中是切實(shí)可行。(2)不同試驗(yàn)工況條件,微型樁最終破壞形態(tài)表現(xiàn)出一致性,即滑面附近,滑面以上受荷段樁身向滑體前緣彎曲變形,滑面一錨固段向滑床后緣彎曲變形,滑面上彎曲點(diǎn)之間樁身發(fā)生傾斜變形,其余部分樁身未有變形出現(xiàn),保持為豎直狀態(tài)。(3)淺層堆積層滑坡治理中,合理樁間距可取8-12d,合理排樁間距可在10d范圍內(nèi)選取,同時(shí)在樁頂布設(shè)連系梁對(duì)樁頂位移限制能起到明顯作用。梅花形布設(shè)群樁試驗(yàn)中,布設(shè)樁頂連系梁分區(qū)樁頂位移比未布設(shè)連系梁分區(qū)樁頂位移降低了25.6%,同時(shí)樁身應(yīng)力在樁身應(yīng)力分布更加均勻飽滿而非僅僅集中在滑面附近。(4)通過對(duì)比樁頂位移迅速增長、樁身應(yīng)力快速增大、樁間土拱破壞樁間土壓力開始減小加載時(shí)間以及對(duì)應(yīng)坡頂豎向均布荷載,可知,這三種試驗(yàn)現(xiàn)象發(fā)展基本是同時(shí)發(fā)生,因而對(duì)于加固之后滑坡穩(wěn)定性情況,可以通過對(duì)樁頂水平位移監(jiān)測(cè)來實(shí)現(xiàn)。
[Abstract]:Of all types of natural disasters in China, the proportion of landslides is as high as more than 50%. In Shaanxi Province, the proportion of landslides in all kinds of natural disasters has reached 62.3%. However, the shallow layer landslide has reached 65% in all kinds of landslides, so it is of great practical significance to carry out the reinforcement and prevention technology for the shallow accumulation layer landslide. With the development of landslide disaster reinforcement technology, the micro-pile is constructed without excavation. It has the advantages of less disturbance to the soil around the pile body, flexible placement of the pile, fast construction speed and good economy, etc. In recent years, more and more applications have been made in shallow pile landslide. However, the theoretical study of micro-pile strengthening landslide is far behind the application of micro-pile in the practical engineering of landslide reinforcement. In view of this situation, this paper takes the similarity principle as the theoretical basis. By means of frame model test, the stress distribution law of pile body in the process of reinforcement of shallow accumulation slope by micro pile is studied. In the experiment, single row pile, double row pile, Three rows of miniature piles are arranged in plum blossom shape to reinforce shallow pile landslide. The reasonable pile spacing, row spacing and the condition of connecting beam at the top of micro pile are explored. By analyzing the experimental data of five groups of model tests, the following conclusions are obtained: when the micro-pile is not installed, the landslide reaches the critical stage of instability and failure after loading 5.6kpa at the top of the slope. However, in the test of three rows of piles in reasonable distribution mode, the landslide reaches the stage of instability and failure, and the top of the slope needs to be applied 24.7 kpa.Thus, it can be seen that the micro-pile is very obvious to improve the stability of the landslide. It is feasible to apply micro-pile in the engineering of shallow pile landslide reinforcement and treatment. (2) different test conditions are available. The ultimate failure pattern of micro-pile shows consistency, that is, near the sliding surface, above the sliding surface is subjected to bending deformation of the pile body towards the front edge of the sliding body in the section of pile. The slip surface-Anchorage section bends towards the back edge of the slide bed, the pile body is inclined to deformation between the bending points on the slip surface, and the other part of the pile body does not deform and remains in a vertical state. 3) during the treatment of the shallow accumulation layer landslide, Reasonable spacing of piles can be chosen within 10 days, reasonable spacing of piles can be chosen within 10 days, at the same time, the arrangement of connecting beams on the top of piles can play a significant role in limiting the displacement of the top of piles. The displacement of the top of the pile in the partition section of the connecting beam with the pile top is 25.6 lower than that of the section without the connected beam, and the stress distribution of the pile body is more uniform and full than the stress distribution of the pile body, which is not only concentrated near the sliding surface, but also increases rapidly by comparing the displacement of the top of the pile with that of the non-connected beam. The stress of pile body increases rapidly, and the soil pressure between piles begins to decrease the loading time and the vertical distribution load corresponding to the slope top. It can be seen that these three experimental phenomena basically occur at the same time, so the stability of the landslide after reinforcement occurs. It can be realized by monitoring the horizontal displacement of the pile top.
【學(xué)位授予單位】：西安工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P642.22;TU473.1

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前1條

1 曹玲;羅先啟;;三峽庫區(qū)千將坪滑坡滑帶土干-濕循環(huán)條件下強(qiáng)度特性試驗(yàn)研究[A];第九屆全國巖土力學(xué)數(shù)值分析與解析方法討論會(huì)論文集[C];2007年

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本文編號(hào)：1596224