發(fā)布時(shí)間：2018-03-28 20:09

  本文選題：既有隧道上方挖方　切入點(diǎn)：模型試驗(yàn)　出處：《西南交通大學(xué)》2015年碩士論文

【摘要】：隨著我國國民經(jīng)濟(jì)的快速發(fā)展,對(duì)交通基礎(chǔ)設(shè)施的需求也在不斷增加。公路、鐵路得到快速發(fā)展,而城市地鐵、城市下穿隧道的修建己成為緩解城市交通壓力的重要手段。隨著交通建設(shè)工程的增加,不可避免的存在在既有隧道上方進(jìn)行挖方類工程的情況。而當(dāng)初始埋深較小時(shí),挖方類工程就會(huì)對(duì)既有隧道產(chǎn)生近接影響。本文依托于國家自然基金項(xiàng)目“既有隧道上方挖填方施工的影響分區(qū)及對(duì)策研究”。通過模型試驗(yàn)、數(shù)值模擬和現(xiàn)場(chǎng)測(cè)試,研究了圍巖等級(jí)、隧道結(jié)構(gòu)健全度、初始埋深對(duì)既有隧道的影響規(guī)律,得出既有隧道上方挖方影響程度分區(qū),結(jié)合實(shí)際工程案例提出施工對(duì)策,并在工程實(shí)例中進(jìn)行運(yùn)用。(1)模型試驗(yàn)中,用相似材料模擬Ⅳ級(jí)、V級(jí)和Ⅵ級(jí)圍巖分別在PVC管和鋼管模擬既有隧道襯砌的情況下挖方過程,采用3.6D、2.4D和1.1D三種初始埋深進(jìn)行試驗(yàn)。(2)數(shù)值模擬對(duì)模型試驗(yàn)進(jìn)行補(bǔ)充和驗(yàn)證,通過數(shù)值模擬和模型試驗(yàn)結(jié)果對(duì)比,找出挖方過程中位移、圍巖壓力和結(jié)構(gòu)應(yīng)力增量變化規(guī)律,總結(jié)出既有隧道上方挖方過程中圍巖等級(jí)、隧道健全度和初始埋深等主要因素的影響規(guī)律。(3)以不同健全度隧道允許應(yīng)力增量為標(biāo)準(zhǔn)對(duì)模型試驗(yàn)結(jié)果進(jìn)行影響分區(qū),分別對(duì)初始埋深3.6D、2.4D和1.1D的情況進(jìn)行影響分區(qū)的劃分,同時(shí)考慮圍巖等級(jí)和隧道健全度對(duì)分區(qū)界限的修正。通過引入殘留埋深比,對(duì)不同初始埋深影響分界進(jìn)行分析,得到統(tǒng)一影響分區(qū),提出圍巖等級(jí)和隧道健全度修正影響分區(qū)的方法。(4)從既有隧道、中間地層和新建工程三個(gè)方面,提出既有隧道上方挖方工程施工對(duì)策。判定連霍高速改擴(kuò)建工程為強(qiáng)影響,采用梁板加固方案,現(xiàn)場(chǎng)監(jiān)測(cè)結(jié)果證明施工過程隧道變形和受力正常。
[Abstract]:With the rapid development of China's national economy, the demand for transportation infrastructure is also increasing. Roads and railways are developing rapidly, while urban subways, The construction of urban underpass tunnel has become an important means to relieve urban traffic pressure. With the increase of traffic construction projects, it is inevitable to carry out excavation projects above the existing tunnels. However, when the initial burial depth is small, Excavation projects will have a close connection effect on existing tunnels. This paper relies on the National Natural Fund project "study on the influence zones and Countermeasures of excavation and filling Construction above existing tunnels." through model tests, numerical simulation and field tests, The influence law of surrounding rock grade, tunnel structure soundness and initial burial depth on the existing tunnel is studied. The influence degree zoning of excavation above the existing tunnel is obtained, and the construction countermeasures are put forward in combination with the actual engineering cases. In the application of the model test, the excavation process of grade 鈪，

本文編號(hào)：1677857