【正文】 bidding, should be supported by the client. He is to account for adequate margins in programming and budgeting whenever a tunnel is to be excavated in difficult ground conditions, according to a risk a assessement evaluation。 this difference in the range of application increases with in creasing diameter of excavation。 instability of excavation walls。 squeezing. ROCK TBM TUNNELLING The practically infinity number of binations rock, soil and environmental conditions which may be encountered during tunnel excavation has determined a great difference in the types and characteristics of the available TBM’s . There are many different schemes for the classification of tunnelling machines. For the example the AITES/ITA Working Group (Mechnisation of Excavation ) is currently working on the definition of an internationally acceptable classification of TBM’s with the purpose of establishing terminology and “terminology” for the optimum choice of the machine (Table 1). 西南交通大學(xué)本科 畢業(yè)設(shè)計(jì) 第 3 頁(yè) Rock tunnelling machine can be grouped in to three main categories (Table2): Unshielded TBM (. Open TBM), Single Shielded TBM which is the way of creating new types of TBM’s that are suitable for application over a wider range of geological conditions, even though the distinction between TBM for rock and TBM for soft ground remains. From the point of view of rock TBM dimensioning, it is necessary to point out that, although TBM’s of more than 10 m in excavation diameter have been constructed, it is always advisable to try to limit the maximum size of the tunnel and therefore that of the TBM. As easily perceived, the reasons for limiting the tunnel diameter are: ? the potential of a TBM in hard rock decreases with in increasing diameter (Kovari et al., 1993。 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。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。 開(kāi)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。 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(kāi)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。 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)。 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。