1、 新建鐵路大準至朔黃鐵路聯絡線ZCZQ11標 馮莊隧道不良地質和高風險段專項施工方案 目錄一、適用范圍3二、編制依據3三、隧道概況和風險分析33.1、隧道概況3、工程概況3、地震動參數5、水文地質特征5、地質構造5、本隧道各級圍巖級別及所占比例53.2、馮莊隧道風險分析63.3馮莊隧道初始風險評價83.4、組織機構11、組織機構及聯系方式12四、不良地質和高風險地段施工方案124.1、塌方風險施工方案124.2、突水突泥風險地段施工方案154.3、變形風險地段施工方案184.4洞口失穩地段施工方案18馮莊隧道不良地質和高風險段專項施工方案為加強隧道施工中不良地質的管理和監控,預防和控制危險源可
2、能出現的緊急情況,盡可能減少事故造成的人員傷亡和財產損失,根據上級要求并結合本工程項目的實際,特制定此專項施工方案。一、適用范圍馮莊隧道二、編制依據 1、中華人民共和國安全生產法2、建設工程安全生產管理條例3、生產安全事故報告與調查處理條例4、安全生產事故隱患排查治理暫行規定5、鐵路工程施工安全技術規程6、馮莊隧道風險評估報告7、施工現場臨時用電安全技術規程8、鐵路隧道鉆爆法施工工序及作業指南9、鐵建設【2007】102號文關于印發加強鐵路隧道工程安全工作的若干意見的通知10、鐵建設函【2007】1007號關于進一步加強鐵路隧道安全工作的通知11、鐵建設【2010】120號關于進一步明確軟弱圍
3、巖及不良地質鐵路隧道設計施工有關技術規定的通知12、設計圖紙及現場的實際情況三、隧道概況和風險分析3.1、隧道概況3.1.1、工程概況馮莊隧道位于中山區,地勢起伏較大,地形較陡峭,自然坡度2030植被不發育。工點所經區域地面標高15021554m,相對高差約52m。隧道進口洞口山坡為臺階地,自然坡約35,黃土層覆蓋較厚。出口山坡較緩,局部可見基巖外露。隧道行政隸屬山西省忻州市神池縣,進口線路右側約350m有小神線通過,交通尚比較便利。隧道起訖里程為DK166+850DK167+421,全長571m,洞身最大埋深約67m,為單洞雙線隧道。整個隧道位于曲線段,左線和右線的曲線半徑分別為R=800和
4、R=804.39。洞內左線路肩設計縱坡為3.2單面上坡。3.1.2、地層巖性工程內地層為第四系上更新統洪,風積砂質黃土;下伏基巖為奧陶系中統灰巖。其巖性特征詳述如下:砂質黃土(Q3pl+eol3):主要分布在隧道進出口,褐黃色,硬塑,土質均勻,顆粒成份以粉粒為主,厚014m,級普通土,0=150KP。黏質黃土(Q3pl+eol3):主要分布在隧道進出口,褐黃色,硬塑,土質不均勻,局部夾粗角礫石,厚約14m,級普通土,0=150KP。奧陶系中統地層:灰巖(O2Ls):灰白色,巖質較硬,隱晶質結構,中厚層狀構造;強風化層厚27m,級軟石,0=500KP;其下弱風化灰巖,級次堅石,0=1200 KP
5、。灰巖巖層產狀近水平。發育三組節理:J1:N85E/80S,為封閉節理。裂隙XX,錳質侵染,節理間距約0.2m;J2:N10E/80S,為封閉節理。裂隙XX,錳質侵染,節理間距約0.3m;J3:N60E/89S,為張開節理。裂隙XX,錳質侵染,節理間距約0.3m,縫寬約40mm,延伸長度約2m。3.1.3、地震動參數根據GB183062001中國地震動參數區劃圖,結合實地調查,隧道區地震動峰值加速度0.10g(地震基本烈度為度),地震動反應譜特征周期0.40s,地震動反應譜特征周期分區為二區。3.1.4、水文地質特征勘察期間未見地下水,屬地下水較為貧乏地區。隧道區地下水埋深大,隧道洞身巖體節理
6、裂隙發育,雨季地表水下滲,局部水量較大,雨季施工時應注意排水。3.1.5、地質構造場地內地形地貌單一,地層巖性主要為第四系上更新統洪、風積砂質黃土及奧陶系中統灰巖,無影響工程的大的斷裂構造。3.1.6、本隧道各級圍巖級別及所占比例隧道各級圍巖分級表里程長度圍巖分級DK166+850DK166+88737DK166+887DK166+92538DK166+925DK166+96035DK166+960DK167+00545DK167+005DK167+10095DK167+100DK167+17070DK167+170DK167+22050DK167+220DK167+28565DK167+28
7、5DK167+36075DK167+360DK167+39636DK167+396DK167+42125圖1 隧道圍巖級別比例圖3.2、馮莊隧道風險分析根據本階段地質勘測資料:本隧道穿越奧陶系中統灰巖,灰白色,弱風化,節理裂隙稍發育,地下水為基巖裂隙水,巖體完整性一般,隧道進出口分布第四系風坡積砂質黃土,褐黃色,具濕陷性,濕陷土層厚度約15m,濕陷系數0.0220.037,為級(中等)自重濕陷性場地。施工中應考慮黃土的濕陷性對隧道的影響,需采取措施進行處理。黏質黃土局部夾粗角礫石,褐黃色,厚約14m,下伏基巖為奧陶系中統灰巖,灰白色,弱風化,節理裂隙稍發育,厚25m,其下弱風化,節理裂隙稍發育
8、。地下水主要為基巖裂隙水,不發育。隧道級圍巖占13%,級圍巖占34%,級圍巖占43%。進出口為新黃土地層,具有濕陷性,上覆土層較薄,洞身頂處地表存有沖溝。因此,本隧道主要風險為塌方、變形、突水突泥、洞口失穩等風險,全隧存在的風險和可能發生的典型風險事件分析如下:1、出口為橋隧相連,施工工序干擾性較大,組織不利容易產生施工安全風險和廢棄分項工程。隧道進口淺埋段,表層為第四系風坡積砂質黃土,穩定性差,基底發現溶洞,出口淺埋段,奧陶系中統灰巖節理裂隙稍發育,洞口邊仰坡開挖。2、DK166+850DK166+887段,進口淺埋段,表層為第四系風坡積砂質黃土,穩定性差,基底發現溶洞,本斷施工施工時,很可
9、能發生塌方,洞口失穩,變形。3、DK166+887DK166+925段,本段為級圍巖黃土淺埋段,施工時,很可能發生塌方,變形。4、DK166+925DK166+960段,本段為土石分界線,施工時很可能發生塌方,突水突泥。5、DK166+960DK167+005段,本段為級圍巖黃土淺埋地段,巖體完整性一般,本段施工時,可能發生塌方,變形。6、DK167+005DK167+100段,級圍巖,巖體整體性一般,施工時可能發生塌方,變形。7、DK167+100DK167+170段,級圍巖水平巖層,巖體完整性一般,施工時可能發生塌方,變形。8、DK167+170DK167+220段,級圍巖水平巖層,施工時
10、可能發生塌方,變形。9、DK167+220DK167+285段,級圍巖水平巖層,巖體完整性一般,施工時可能發生塌方,變形。10、DK167+285DK167+360段,級圍巖,巖體完整性一般,施工時可能發生塌方,變形。11、DK167+360DK167+396段,級圍巖地段,節理裂隙稍發育,施工時可能發生塌方,變形。12、DK167+396DK167+421段,出口淺埋段,奧陶系中統灰巖節理裂隙稍發育,洞口邊仰坡開挖,施工時可能發生塌方,洞口失穩,變形。綜上所述,馮莊隧道存在的安全風險類型有:突水突泥、埸方、洞口失穩、大變形。突水突泥主要集中在DK166+925DK166+960段;本隧道全隧
11、均存在高度和中度等級的埸方風險;變形風險主要集中于隧道進口、出口、洞身淺埋地段,全隧變形風險等級均為高度及以下。洞口淺埋段容易發生洞口失穩。3.3馮莊隧道初始風險評價通過風險分析,馮莊隧道各段落中存在的初始風險評價結果見表1:經評估,本隧道中的主要典型風險事件類型為塌方、洞口失穩、大變形及突水突泥風險;初始風險為高度及以上的共有20處。具體情況如下:1、塌方風險11處風險等級為高度的段落共3處,風險等級為中度度的段落共有9處。2、突水突泥風險1處風險等級為高度的段落共1處。3、變形風險10處風險等級為高度的段落共2處。4、洞口失穩2處風險等級進口處為高度風險等級,出口為中度風險等級。Opini
12、ons and suggestions on the partys mass line educational practiceAccording to the central and provincial, municipal unified deployment, according to municipal Party committee about carrying out the partys mass line educational practice activity in the citys implementation opinions, the spirit of the
13、partys mass line educational practice activities from 20* in January to 99 months, carried out at all levels of departments and directly affiliated institutions and grass-roots party organizations. According to my actual County, the county to carry out the education practice put forward the followin
14、g implementation opinions.First, the overall requirementsCounty county education practice to the eighteen Party of eight, the spirit of the the third Plenary Session of the 18th CPC Central Committee as the guidance, conscientiously implement the spirit of general secretary Xi Jinping book series of
15、 important speech, earnestly implement the Central Committee really, opinions and advice , party implementing the guiding ideology of opinions to determine the objectives and requirements, step method, in accordance with the look in the mirror, dress up, wash bath, cure treatment, the general requir
16、ements of for the people pragmatic honest people as the theme, in carrying forward the spirit of Zhuanglang Zhuang, improve their work style, service to the masses of the people, the foundation of consolidating grassroots, promote transformation across efforts, to further implement the central eight
17、 regulations and The opposition party and government austerity waste regulations , double section provincial regulations, municipal provisions of the twelve plan and the implementation measures for on improving the work style of close ties with the masses law, highlight style building, carry out the
18、 whole wind spirit, resolutely oppose formalism, bureaucracy, hedonism and wasteful extravagance to solve the problems, Party members and cadres of the style and the masses of people strong, the Ministry of Party members and cadres to further improve their thinking and understanding, to further chan
19、ge the style of the wind, the masses to close, honest and pragmatic people honest image to further establish the foundation to further reinforce the basic level. Style of the building of the new results to promote the construction of a powerful force of the county and the ecological culture of the c
20、ounty and county construction.In educational practice activities of the unit is mainly: the county and below county departments under the organs, enterprises and institutions directly under the township, street, and community, village, non-public economic organizations, social organizations and othe
21、r grass-roots organizations. Agencies and branches, each single unit, follow the rules on internal institutions. Educational practice with step by step.To adhere to the county leadership, leadership and leading cadres to focus on outstanding catch to directly contact the service of the masses of law
22、 supervision departments and window units, service industry, educational practice, pay attention to grasp the heavy towns, streets and villages, community education activities and the masses of grassroots groups in close contact to strengthen, and the majority of Party members, cadres and the mass l
23、ine line Marx doctrine view of the masses and the partys education.Always speak seriously as a basic attitude, adhere to positive education, to carry out criticism and self criticism group, adhere to the pragmatic, more emphasis on leadership, pay more attention to the layers of the demonstration, m
24、ore focus on the four winds, solve the problem, pay more attention to open the door, the participation of the masses, pay more attention to the classification guidance. Orderly, pay more attention to the cooperation and cohesion driven, more strict requirements on injection, really supervision pract
25、ice, ensure education practice is not empty is not empty is not partial, not as a mere formality.Two, the key point of the taskThe main task of the countys education practice is to seize against four wind this focus on centralized solve outstanding problems asked County, township leadership and lead
26、ing cadres of the four winds, the disadvantages of the style, scale behavior to a large scale investigation, overhaul, cleaning greatly. At the same time, respond to the concerns of the masses, safeguard the interests of the masses, pay attention to solve practical problems, solve the people around
27、the unwholesome tendencies especially on eat, take the card, Yong lazy luxury, extravagance and waste fees, privileges and other issues, timely and effective, without any discount to solve, to improve the style of real implementation of the requirements of real to the grassroots, real let group Bene
28、fit the public.(a) focus on solving the four winds outstanding issuesThe central and provincial requirements, the county leadership and leading cadres of key performance concept is not correct, do not dare to play, to engage in image project, political project, a leadership guide, a set of ideas, or
29、ders and prohibitions, and a policy, there are countermeasures county. The units directly under the heavy focus on solving Yung lazy drag, buck passing skin, work is not implemented, the service is not active. The dynamic problem of law enforcement and supervision departments and window units, servi
30、ce industry mainly solve the door hard, ugly face, something difficult, and arbitrary charges, fines, levies, and breach of privilege, chinakayao, not the problem of law. The township, street The collar of leading bodies and leading cadres to solve key does nottheir own conditions to develop the cor
31、rect road, the maximum to avoid investment risk, gain profit.(three) vigorously promote the brand. To establish brand awareness, awareness of the use of brand, brand value, brand acquisition performance, enhance the competitive strength. Concentrated manpower, careful planning, packaging and publici
32、ty of a number of unique, market influence and coverage of the brand, the implementation of key breakthroughs, to enhance the competitive strength, walking business road the competition of alienation and characteristics, the pursuit of stability and development of the market.(four) to promote the in
33、tegration of resources. To further broaden their horizons, effective integration of resources within the group, the city resources, other industries and regional resources, mutual trust, mutual benefit, seeking win-win principle, in the framework of national policies and regulations, strict inspecti
34、on and argumentation, legal consultation, examination and approval procedures, strict regulation of economic activities, attract injection the social investment to the industry group, to achieve leveraging the development, ensure that the value of state-owned assets.(five) to strengthen the construc
35、tion management personnel. Strengthen the management of education and training of cadres and workers of the existing business, firmly establish the concept of the market, enhance the sense of crisis to adapt to market competition, the sense of urgency, improve the ability to respond to market compet
36、ition, improve management and operation of the market. At the same time, according to the need of industrial development, vigorously the introduction of high-quality management management personnel, and strive to build a high-quality professional management team, hard work, and promote the entire wo
37、rkforce knowledge structure, age structure, structure optimization and upgrading ability, enhance core competitiveness, adapt to the need of market competition.(six) seriously study the policy for policy. Serious research about social support the development of cultural undertakings in the country a
38、nd the XX policy, especially the policy of industrial development, financial investment policy, financial policy and tax policy, and actively seek policy, projects and funds, enterprise and industry group mission to promote leapfrog development.11 中鐵二十一局準池鐵路項目部表1 馮莊隧道風險等級分析評價馮莊隧道風險評估表里程長度(m)初始風險風險處理
39、措施殘余風險殘余風險處理起始里程終止里程風險事件概率等級后果等級風險等級概率等級后果等級風險等級加強監控量測DK166+850DK166+88737塌方、洞口失穩、變形43高度108管棚預加固,巖溶普查,錨噴支護,CRD法施工21低度加強監控量測DK166+887DK166+92538塌方、變形43高度42超前小導管預加固地層,三臺階七步開挖法施工21低度加強監控量測DK166+925DK166+96035塌方、突水突泥43高度42超前小導管預加固地層,加強初期支護21低度加強監控量測DK166+960DK167+00545塌方、變形32中度級圍巖復合式襯砌,格柵鋼架,環形開挖預留核心土施工2
40、1低度加強監控量測DK167+005DK167+10095塌方、變形32中度級圍巖復合式襯砌,格柵鋼架,臺階法施工21低度加強監控量測DK167+100DK167+17070塌方、變形32中度及時施工支護,優化系統錨桿布置,臺階法施工21低度加強監控量測DK167+170DK167+22050塌方、變形22中度級圍巖復合式襯砌11低度加強監控量測DK167+220DK167+28565塌方、變形32中度及時施工支護,優化系統錨桿布置,臺階法施工21低度加強監控量測DK167+285DK167+36075塌方、變形32中度級圍巖復合式襯砌,格柵鋼架,臺階法施工21低度加強監控量測DK167+36
41、0DK167+39636塌方、變形32中度42超前小導管預加固地層,環形開挖預留核心土法施工21低度加強監控量測DK167+396DK167+42125塌方、洞口失穩、變形32中度108管棚預加固地層錨噴支護,環形開挖預留核心土法施工21低度加強監控量測 序號風險事件風險產生原因險源類別后果備注1變形塌方埋深、圍巖穩定性、地質構造、地下水、初支失效和施工質量地質、地形、施工因素可能引發重大安全事故2炸藥意外爆炸裝藥時帶火種、鉆眼與裝藥平行作業施工因素可能引發重大安全事故3產生盲炮導爆索、雷管安裝不規范、火工品質量施工因素可能引發重大安全事故4塵、毒、噪聲污染通風不及時、干鉆、不戴防護用具施工因
42、素可能損害人員健康5觸電洞內電路安裝、維護或使用不規范或違章施工因素可能引發重大安全事故6洞頂落石清危排險不徹底或初支不及時或方法不當施工因素可能引發重大安全事故7車輛碰撞洞內排風不暢、能見度低或車上過快施工因素可能損害人員健康 隧道風險清單 3.4、組織機構組 長:項目經理副組長:項目副經理、項目總工各工序安全控制各業務部門領導工區隊長、工班長各工點安全控制安全管理領導小組3.4.1、組織機構及聯系方式隧道施工事故總指揮樊 永 連搶險行動組組長:劉文忠對外協才調組組長:相立群現場技術組組長:張忠德通訊聯絡組組長:鄭東來物資設備組組長:趙四方疏散救護組組長:鄧文付四、不良地質和高風險地段施工方
43、案4.1、塌方風險施工方案1、做好超前地質預報,采用以鉆探為主,地震波法、紅外線等多種物探法遠期與近期相結合的綜合判定。以摸清斷層的圍巖結構和富水情況,為制定相應的對策提供第一手資料;根據地質變化及早制定預案和措施。2、洞口淺埋段宜采用CRD施工方法和環形預留核心土施工方法,洞身級圍巖宜采用臺階法、級圍巖黏質黃土淺埋段宜采用三臺階七步開挖、其余級圍巖宜采用環形預留核心土、級圍巖宜采用全斷面施工方法;加強初期支護和鋼架鎖腳錨桿等措施。3、進口DK166+850DK166+887洞口開挖邊坡臨時防護采用錨噴支護,噴混凝土(C25)厚10cm;錨桿22,長度3m,間距1.21.2m,梅花型布置;鋼架
44、網采用8,間距2525cm。永久邊坡采用骨架護坡,形成綠色防護。隧道洞門擋墻、端墻基礎采用三七灰土換填2m,換填應嚴格按照現行濕陷性黃土地區建筑規范的施工要求施做。4、進口DK166+850DK166+887洞口暗挖段采用一排108mm長40m超前大管棚支護進洞,出口DK167+396DK167+421洞口暗挖段采用108mm長28m超前大管棚支護進洞.5、DK166+854DK166+890段。隧底距軌面高程約11.514.0m存在黏土充填溶洞,考慮運營安全,對溶洞進行注漿處理,處理范圍為隧道中線兩側各15m,注漿孔間距1.51.5,梅花型布置,施工中應加強隧道基地巖溶普查,更具揭示的溶洞形
45、態與隧道的關系,進行綜合治理,動態設計。6、本隧道洞身巖層層理平緩且裂隙較發育,隧道開挖后容易造成層間黏結強度下降,支護不及時,易掉塊,局部塌方。隧道級圍巖平緩巖層地段,施工中應加強監控量測,注意觀察拱部巖體變化,開挖后及時施作初期支護,可根據圍巖情況,優化系統錨桿布置,加強拱部支護,錨桿總數不變,施工時可根據巖體破碎程度及層間黏結力綜合判斷,必要時采取加強支護措施。7、隧道洞身超前支護表23馮莊隧道超前支護表里程長度(m)襯砌類型超前支護及其他措施施工方法起始里程終止里程DK166+850DK166+88737b型復合式襯砌108大管棚超前預支護,長度40m,環向間距40cmCRD法DK16
46、6+887DK166+92538b型復合式襯砌42 超前小導管, 環向間距40cm,t=3.5mm,4榀一環三臺階七步開挖法DK166+925DK166+96035b型復合式襯砌42 超前小導管, 環向間距40cm,t=3.5mm,4榀一環三臺階七步開挖法DK166+960DK167+00545級圍巖復合式襯砌42 超前小導管, 環向間距40cm,t=3.5mm,3榀一環環形開挖預留核心土DK167+005DK167+10095級圍巖復合式襯砌臺階法DK167+100DK167+17070級圍巖復合式襯砌臺階法DK167+170DK167+22050級圍巖復合式襯砌全斷面法DK167+220D
47、K167+28565級圍巖復合式襯砌臺階法DK167+285DK167+36075級圍巖復合式襯砌臺階法DK167+360DK167+39636級圍巖復合式加強襯砌42超前小導管, 環向間距40cm,t=3.5mm,3榀一環 環形開挖預留核心土DK167+396DK167+42125級圍巖復合式加強襯砌108大管棚超前預支護,長度28m, 環向間距40cm環形開挖預留核心土7、嚴格控制開挖進尺。嚴格遵循“管超前、弱爆破、強支護、早封閉、勤量測、及時襯砌”的施工原則,確保不出現塌方。及時噴射砼,必要時摻加鋼纖維,以增加支護的強度。8、施工中加強系統支護監控量測,并根據監控量測結果及時調整初期支護
48、及施作二次襯砌。9、橋隧相連的進出口洞門施工,合理的安排施工工序,精心的施工組織。10、現場備足封堵材料,如砂袋、袋裝水泥、TGRM漿、發泡注漿搶堵劑等,同時在現場儲備足夠排水設備。11、洞內設置逃生管道。逃生管道設置在沿隧道墻角地面處設置,管口一端距下臺階不大于5 m,另一端延伸至已做襯砌段6米的位置。管道采用直徑800mm的承插鋼管。管道內預留工作繩、應急水管(飲用)、電話線、照明線等。12、當發生塌方事故時,人員應立即撤離工作面,在有條件并保證人員安全的情況下撤出設備。同時作業人員及時向項目部匯報。項目部根據發生塌方的位置、原因、范圍以及圍巖的暫時穩定程度制訂控制方案。4.2、突水突泥風
49、險地段施工方案本標段隧道巖層節理發育,導水性強,貫通性較好,在這種地質條件下易出現突水、突泥。施工時采取如下施工方法。1、為了保證各個工作面的施工人員能夠及時撤離,洞內建立統一的報警系統,并根據危險程度的不同,確定預警等級,根據預警等級的不同,確定不同的報警信號,報警信號要能夠明確辨別,防止由于信號辨別不清,造成撤離的混亂。2、開挖采用三臺階七步開挖法,減少一次進入斷層或富水段的工作面積。開挖時盡可能采用機械開挖,不宜采用爆破開挖,若必須采用爆破開挖時,堅持多打眼、少裝藥的弱爆破施工技術,減小對圍巖的擾動。上部斷面開挖時,工作面水平鉆機超前探水孔深3050m,進行泄水,然后再進行開挖。3、若隧
50、道開挖后出現局部滲水,根據不同情況采取相應措施,地下水狀態級(滲水量10L/min10m),可采用噴射混凝土封堵滲水。地下水狀態、級(級,滲水量1025L/min10m,級,滲水量25125L/min10m),隧道采用徑向注漿止水措施,以確保施工安全、防止地下水大量流失,并對附近居民的水井、泉水出露點進行長期觀測,防止隧道施工造成地表水干涸。注漿堵水后,地下水狀態應達到無水或小于地下水狀態級(干燥或濕潤:滲水量3L/min10m)方可施工防水板和二次襯砌。帷幕注漿施工方案:注漿方式采用超前預注漿、后注漿、局部注漿、補注漿四種方式相結合,基本注漿方案分為下列幾種:超前預注漿:隧道開挖后全斷面徑向
51、注漿,每循環長度15m,固結范圍為開挖輪廓線外3.5m,施工時根據實際地質情況進行調整。后注漿:待每個環節注完后,可鉆23個檢查孔檢查注漿效果,如未達到預期效果,應以小導管壓注補充注漿。局部注漿:洞室開挖后,如果局部還有漏水,可進行局部直接暴露注漿。補注漿:上述三種注漿方式實施后,仍未達到設計要求時,根據實際情況選擇上述注漿方式一種或幾種進行補充注漿。注漿材料:注漿材料選用普通水泥漿、TGRM漿,如局部出現漏漿可采用發泡注漿搶堵劑進行封堵。在隧道開挖過程中,及時進行超前地質預報,以摸清斷層的圍巖結構和富水情況,為制定相應的對策提供第一手資料;根據實際情況擬采用全封閉或半封閉注漿止水固結施工技術
52、;4、嚴格遵守“管超前、短進尺、弱爆破、強支護、快封閉、勤量測”的原則進行施工。增加大管棚、小導管等超前支護措施,改用CRD法開挖,及時噴射砼,必要時摻加微纖維,以增加支護的強度。現場備足封堵材料,如砂袋、袋裝水泥、TGRM漿、發泡注漿搶堵劑等,同時在現場儲備足夠排水設備。5、在掌子面涌水、突泥早期,為了控制涌水量和水壓力,在掌子面附近配備足夠的堵漏材料,如快凝、早強水泥,鋼釬、木楔等,當巖石裂隙或巖溶管道涌水量不大時可直接采用麻絲膠泥封堵,涌水量大時,采用錘頭打入纏有麻絲膠泥的木楔或鋼釬封堵,為了降低涌水速度,在距離掌子面一定距離1020m砌筑砂袋墻,加快泥砂淤積,減少出水口和涌水量,砂袋墻
53、的寬度一般超過5m。6、反坡施工段落配置足夠的抽水設備,對長距離抽水設置梯級泵站。7、黃土沖溝段,部分淺埋段采取明洞通過,對洞頂加強地表水監測及做好隔水、引排,其他段采取雙側壁導坑法或三臺階七步開挖法,加強支護措施通過。4.3、變形風險地段施工方案1、分不同的地層采用不同的支護參數和不同的施工方法來控制圍巖變形。2、現場測試圍巖松動圈的范圍,根據圍巖應力特征,采用加大預留變形量、加長錨桿、加強支護參數等來控制變形。3、嚴格貫徹“短開挖、弱爆破、強支護、快封閉、勤測量、及早襯砌”原則進行施工。4、加強監控量測,適時調整初期支護措施,仰拱緊跟,及時襯砌。5、對于膨脹土質段落,主要通過變形留夠、底部
54、加強等措施,人工或機械開挖,減少圍巖擾動降低風險。6、發生擠壓大變形時,必要時采用多重支護、分次施工技術來控制變形。4.4洞口失穩地段施工方案 隧道進口、出口位于淺埋段,洞口施工將會對土體擾動洞口山體失穩,為保證施工安全,應加強施工過程中的監控和管理。 洞口開挖安全注意事項: 洞口邊坡開挖前,先在明洞邊坡開挖線外布置觀測點,嚴密洞頂圍巖變化。觀測點應布置在仰坡頂510m的范圍,間距每5m一個。還應根據巖層走向、厚度、頂部位置具體設置,應保證能觀測到順層巖體的位置變化。豎向觀測數據,分析洞頂圍巖變化,當洞頂沉降出現突變,產生較大的橫向、豎向位移時,應實地觀測洞頂地表有無出現裂縫,并加強觀測。如果
55、觀測數據有繼續加大,裂縫寬度變大或者數量增多,則洞口可能出現失穩需要停止進洞進行處理。洞口段正洞施工:a、進洞開挖,開挖方式采用CRD法。遵循“短進尺、弱爆破、早封閉、勤量測”的施工原則,每循環進尺以一榀拱架間距為宜,盡量采用預裂爆破。b、觀測記錄工作面的工程地質與水文地質情況,作地質素描。觀測開挖面附近初期支護狀況,判斷圍巖、隧道的穩定性和初期支護的可靠性。由地質組進行,其他技術人員協助。c、地表量測:在級圍巖且埋深小于40m的地段軸向每隔510m布設。同時在橫向依據實際情況,選定主斷面,沿主斷面布設測點,以了解地表沉降的橫向影響范圍。d、洞內量測:按照設計及規范要求,對隧道進行拱頂下沉及圍巖收斂量測,發現圍巖變化異常立即采取加固措施,確保施工安全。