【正文】 并控制巖體的變形。 3．為了改善支護(hù)結(jié)構(gòu)的受力性能，施工中應(yīng)盡快閉合，而成為封閉的筒形結(jié)構(gòu)。 6．二次襯砌原則上是在圍巖與初期支護(hù)變形基本穩(wěn)定的條件下修筑的，圍巖和支護(hù)結(jié)構(gòu)形成一個整體，因而提高了支護(hù)體系的安 全度。 2．洞室開挖后， A點在臨空面失去約束，原始應(yīng)力狀態(tài)要調(diào)整，如果圍巖的強度足夠大，那么經(jīng)過應(yīng)力調(diào)整，洞室可處于穩(wěn)定狀態(tài)（不需支護(hù)）。即圍巖發(fā)生變形，可釋放一定的荷載（卸荷作用），所以要允許圍巖產(chǎn)生一定的變形，以充分發(fā)揮圍巖的自承能力。 3．隧道結(jié)構(gòu)體系 =圍巖 +支護(hù)體系。 一、隧道施工方法選擇隧道施工方法的選擇，主要根據(jù)工程地質(zhì)及水文地質(zhì)條件、施工條件、圍巖類別、隧道埋置深度、隧道斷面尺寸大小和長度襯砌類型，應(yīng)以施工安全為前提及以工程質(zhì)量為核心，并結(jié)合隧道的使用功能，施工技術(shù)水平、施工機(jī)械裝備、工期要求和經(jīng)濟(jì)可行性等因素綜合考慮研究選用。 （一）全斷面法。 全斷面開挖法有較大的作業(yè)空間，有利于采用大型配套機(jī)械化作業(yè)，提高施工速度，且工序少、干擾少，便于施工組織和管理。因此要求進(jìn)行精心的鉆爆設(shè)計和嚴(yán)格控制爆破作業(yè)。其開挖順序是上半部開挖拱部錨桿噴射砼支護(hù)，拱部襯砌，下半部中央部分開挖，邊墻部分開挖，邊墻錨桿噴射砼支護(hù)及襯砌。 超短臺階法：上臺階僅超 前 3－ 5m，斷面閉合較快。臺階有利于開挖面的穩(wěn)定性。 （三）分部開挖法。 上下導(dǎo)坑超前開挖法（即上下導(dǎo)坑先拱后墻法）：此法適用于 Ⅱ 、 Ⅲ 類圍巖，在松軟地層開挖隧道，一般宜采用上下導(dǎo)坑超前開挖先拱后墻法。 單側(cè)臂導(dǎo)坑法：圍巖穩(wěn)定性較差，隧道跨度較大，地面沉陷難以控制時采用此方法。 Ⅲ、隧道主要施工工藝 一、 洞口段施工： 邊仰坡開挖： 全站儀測量放樣，利用挖掘機(jī)自上而 下逐段開挖，不得掏底開挖或上下重疊開挖，清除洞口與上方有可能滑塌的表土，灌木及山坡危石等，石質(zhì)地層仰坡開挖需要爆破時，應(yīng)以淺眼松動爆破為主。 河南理工大學(xué)本科設(shè)計畢業(yè)論文 7 截水溝施工： 在距仰坡坡口 5 米處開挖截水溝，截水溝開挖以機(jī)械為主，人工配 合修整，修整完后，立即砌筑 漿砌片石，并用砂漿抹面。施工），方向與線路中線平行； n 鋼管施工誤差：徑向不大于 20 ㎝； n 隧道縱向同一截面內(nèi)接頭數(shù)不大于 50%，相鄰鋼管的接頭至少錯開 1 米。水泥漿與水玻璃體積比 1： ；水泥漿水灰比 1：1；水玻璃濃度 35波美度；水玻璃模數(shù) ；注漿壓力初壓 ~；終壓。每打完一排鋼管后，應(yīng)立即噴漿封閉開挖面 ,然后注漿 .注漿后，架設(shè)鋼拱架，初期支護(hù)完成后，每隔（ 2~3 米，試圖紙而定）再另打一排鋼管，超前小導(dǎo)管搭接長度一般為 米。 50CM），固定牢固不得晃動，有管的必須中間穿鐵絲通過。模板每隔一定距離內(nèi)外固定，保證不位移，模板的接頭應(yīng)緊密平順，不得有離縫、歪斜和不平整等現(xiàn)象，模板接頭及底部均不得漏漿。虛高可高出 10%，使震實后的面層標(biāo)高與設(shè)計相符。安設(shè)溝墻摸板，要求摸板位置準(zhǔn)確，縱向一條線。按設(shè)計尺寸要求挖端墻基礎(chǔ)。 明洞拱頂回填應(yīng)對稱分層夯實。 河南理工大學(xué)本科設(shè)計畢業(yè)論文 10 Ⅳ .工程實例 新奧法的引進(jìn)是從錨桿和噴混凝土一類“主動型”的新型支護(hù)技術(shù)的推廣使用開始的。 修建在砂夾礫石松散地層中的北京地鐵復(fù)興門折返段隧道就是一個典型的例子。在中國，這種方法稱之為“淺埋礦山法”。 廣州地鐵東段也是采用淺埋礦山法修建的。同國際上的情況一樣，為了解決長期以來困擾著人們的粉塵污染環(huán)境，回彈嚴(yán)重以及混凝土品質(zhì)的不均勻性等問題，正在大力推行濕噴工藝。 可以毫不夸張地說，新奧法的推行確實引起了礦山法修建技術(shù)在開挖方法、施工技術(shù)乃至于隧道設(shè)計思想方面的重大變革。 對于“新奧法”一詞的內(nèi)涵，人們的認(rèn)識有一個發(fā)展的過程。闡明這一點，有重要的現(xiàn)實意義。 那么，什么是新奧法概念的內(nèi)涵？有人歸結(jié)為 22 條，有人歸結(jié)為 7條。其目的都是為了“保護(hù)圍巖，調(diào) 動和發(fā)揮圍巖的自承能力。 The other hand, have to limit it, Rock is not so lax and excessive loss or greatly reduced carrying capacity. During construction should be used with rock close to, the timely building puzzle keeps strengthening Flexible support structure, such as bolting and shotcreting supporting. This adjustment will be adopted supporting structural strength, Stiffness and its participation in the work of the time (including the closure of time) to control the deformation of the rock mass. （ 3） . In order to improve the support structure, the mechanical properties, the construction should be closed as soon as possible, and to bee a closed cylindrical structure. In addition, the tunnel shape with a round should, as far as possible, to avoid the corner of the stress concentration. （ 4） . Construction right through the rock and supporting the dynamic observation, measurement, and reasonable arrangements for the construction procedures, changes in the design and construction management of the daytoday. 河南理工大學(xué)本科設(shè)計畢業(yè)論文 15 （ 5） . To lay waterproof layer, or is subject to bolt corrosion, deterioration of rock properties, rheological, swelling caused by the followup to load, use posite lining. （ 6） . Lining in principle, and the early rock deformation Supporting the basic stability of the conditions under construction. rock and supporting structure into a whole, thereby improving the support system of security. NATM above the basic elements can be briefly summarized as : less disturbance, early spray anchor, ground measurements, closed tight. 3． With a spring to understand the principle NATM （ 1） . Cavern brink of a point A in the original excavation ago with stress (stress selfrespect and tectonic stress) in a state of equilibrium. As an elastic stiffness of the spring K, P0 under pression in a state of equilibrium. （ 2） . Cavern excavation, A point in attacking lose face constraints, the original stress state to be adjusted, if the intensity of rock big enough, After less stress adjustments may cavern in a stable condition (without support). But most of the geological conditions of the poor, that is, after the stress cavern adjustments, such as weak protection, we could have convergence deformation, even instability (landslides), must be provided to support power PE, in order to prevent landslides instability. Equivalent to the Spring of deformation u, in the role of PE is now in the midst of a state of equilibrium. （ 3） . By the mechanical balance equation, we can see in the spring P0 role in a state of equilibrium。 (3) When u=umax, landslides, have relaxation load and unsafe. 4. Points （ 1） . Rock cavern excavation is affected by that part of rock (soil) body, the rock is a trinity : have a load bearing structure, building materials. （ 2） . Tunnel construction is in the rock stress is of special architectural environment, which can not be equated with the construction on the ground. （ 3） . Tunnel structure rock + = bracing system. II. The new Austrian highway construction in the basic method NATM one of the characteristics is the scene monitoring, measurement information to guide construction, through the tunnel construction measure receipts and excavation of the geological observation for prediction and feedback. And in accordance with the established benchmark for measuring the tunnel construction, excavation section steps and sequences, Supporting the initial parameters for reasonable adjustments to guarantee the safety of construction, a tunnel rock stability, the quality of the project and supporting structure of the economy and so on. The author of mitments (Chengde) Chek (Chifeng) East Maojingba Tunnel NATM basic construction method for investigation concluded, synthesis of a new highway tunnel Natm the selection of different types and the basic characteristics of the construction methods and tips. 1. A tunnel construction method of choice tunnel construction method of choice, mainly based on the engineering geological and hydrogeological conditions Construction, rock type, buried deep t