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土木工程外文翻譯---在不良地質(zhì)條件下的隧道掘進(jìn)-建筑結(jié)構(gòu)-預(yù)覽頁(yè)

 

【正文】 e achieved through the standardization of the section types for road, motorway, and railway tunnels. The could favour the reuse of homogeneous construction works, in addition to gaining considerable advantages in construction times and costs. As well known, the value of the TBM, in terms of direct project costs, is rekatively insignificant. Failure to achieve the desired results and maintain the time schedule, however, significantly affects the project. From the outset it is therefore important to adopt the approach of utilizing the best possible equipment, as far as all the aspects pertaining to the TBM, and the supporting services are concerned. Generally speaking, the most reliable machines are the simple ones as they have the least amount of equipment that can break down (Foster, 1997). In fact, the TBM that is designed to cover all eventualities has too frequently in the past, tended to be problematic in service and produced performances below expectations. On the basis of the above considerations and recent and past experience, it is possible to establish the following points regarding the selection of the type of TBM: TBM the shielded TBM’s have a wider range of application than the open TBM’s。 the choice between a single shielded and a double shielded TBM depends on the design of the tunnel section and whether it is necessary to install a precast lining along the entire length of the tunnel to be constructed. 西南交通大學(xué)本科 畢業(yè)設(shè)計(jì) 第 5 頁(yè) It should be recalled that in a tunnelling project there are other problems which need to be solved in addition to the technical ones, .: one should be reminded that today there are TBM’s which can reduce significantly the number of geological situations which cause important problems to face advance assuming that these that these TBM’s are correctly designed and utilized。 the importance of the contractor’s expertise and, above all, the personnel director and technical staff on set, is often not given the right attention, while in reality it plays a primary role in the functioning of a TBM, particularly under limiting condition。下面是由TBM進(jìn)行掘進(jìn)的有關(guān)機(jī)器選型和尺寸的說(shuō)明,關(guān)注于使用TBM進(jìn)行掘進(jìn)的地質(zhì)條件的限制及地質(zhì)和地質(zhì)觀測(cè)的重要性,所以,要恰當(dāng)理解隧道沿線的圍巖狀況。 在不良地質(zhì)條件下往往產(chǎn)生大量的弱質(zhì)巖石,這樣會(huì)使隧道處于不穩(wěn)定狀態(tài),或者產(chǎn)生大量的硬巖,會(huì)降低掘進(jìn)速度。 開挖橫斷面 100m*m,地質(zhì)年代為前寒武紀(jì),片麻巖,巖石穩(wěn)定:每米隧道平均打7-8?jìng)€(gè)錨桿進(jìn)行支護(hù),外加 7cm 厚的噴混襯砌?;谒x的幾例情況,該討論聚焦于相對(duì)重要和困難的地質(zhì)情況:可挖性的限制,開挖洞壁的不穩(wěn)定性,開挖掌子面的不穩(wěn)定性,斷層,擠壓狀態(tài)。 硬巖掘進(jìn)機(jī)主要分為三類(表2):無(wú)護(hù)盾 TBM(例如:敞開式 TBM),單護(hù)盾式 TBM,該種為創(chuàng)新型的 TBM,即便存在硬巖式和軟巖式 TBM,該鐘卻適用于多種類型地質(zhì)條件。然而對(duì)于超過(guò) m 的開挖直徑,就目前的技術(shù)而言,可能還達(dá)不到完滿實(shí)現(xiàn)運(yùn)用 TBM 進(jìn)行硬巖開挖的水平。 通過(guò)公路,高速公路和鐵路的標(biāo)準(zhǔn)化改造,可充分發(fā)揮使用 TBM 的優(yōu)勢(shì)。所以,一開始盡可能使用與TBM有關(guān)各方面最好的設(shè)備及服務(wù)很 西南交通大學(xué)本科 畢業(yè)設(shè)計(jì) 第 9 頁(yè) 重要。 應(yīng)該想到在隧道施工中除了技術(shù)方面,還有其他問(wèn)題需要解決。根據(jù)評(píng)估,隧道開挖在不良圍巖狀況下進(jìn)行,在設(shè)計(jì)和預(yù)算方面要充分地考慮到差額;此方法對(duì)采用鉆爆法進(jìn)行施工的隧道同樣適用。
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