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1、 小湾电站导流隧洞洞身开挖及支护工程施工摘要：小湾洞身自上而下分三层进行开挖支护。层开挖考虑到开挖机械性能及支护施工的需要，确定开挖高度约为89.55m；层开挖高度为10.5 m；层主要为保护层开挖，开挖高度1.73.15m。1#、2#导流洞层导洞开挖采用两台三臂台车进行两个工作面的开挖，其余工作面开挖采用手风钻开挖。F7断层带采用I20a工字钢拱架。渐变段I层开挖方案采用44小导洞超前，洞口10m大跨度段分两半分别进行开挖支护，其余20m段全断面一次扩挖到位。1洞出口12m段及2#洞出口20m段由洞挖改为槽挖，将f23断层切除，二次衬砌支护改为明拱，出口5m段自外向内分半开挖支护，开挖前洞脸
2、设预应力锚杆锁口。 键词：小湾 导流隧洞 开挖 支护 F7断层 渐变段 出口 1 工程概况1.1 设计参数 小湾水电站1#、2#导流洞均布置于左岸，进口底板高程为988.0m；出口底板高程为984.984m；两条导流洞平行布置，中轴线间距48m。1#、2#导流洞各由30米长进口渐变段，60米长的堵头段和标准断面组成，两洞长分别为861.592m、980.922m，底坡分别为0.3627%、0.3172%，衬砌断面为1619m及1619.5m（顶拱不衬段）城门洞形。隧洞开挖及支护断面根据地质条件共设六种形式，开挖标准断面尺寸有17.320.2、17.420.25、19.422.2、2
3、0.423.2四种；隧洞沿线边墙、顶拱进行系统喷锚支护；不良地质地段挂网喷25cm钢纤维砼，增设工字钢拱架加强支护。1.2 地质条件 本工程两条导流洞埋深均为30230m，最大埋深约260m，围岩以微风化新鲜岩体为主，少量弱风化和卸荷岩体主要分布在洞室的进、出口段。围岩岩性主要为黑云花岗片麻岩及角闪斜长片麻岩，二者均夹片岩。围岩类别为类，其中，类围岩分布在进口洞段，1#、2#导流洞类围岩分别占总长的81%、83.8%，、类围岩分别占总长的19%、16.2%。洞身还分布有一条级断层（F7），4条级断层为F11、F5、F19、F23等。还有若干分属级结构面的小断层、挤压面和节理组，断层影响带岩体破
4、碎。地下水以基岩裂隙潜水为主，水位一般高出隧洞顶拱30m200m，围岩多具微透水性。1.3 主要工程数量 石方洞挖65万m3，喷砼1.4万m3，锚杆3.3万根，挂网76t，钢拱架1096 t。1.4 施工进度 小湾电站导流隧洞开挖支护计划执行情况如下：进口施工支洞计划开、竣工时间：2002年4月1日2002年7月31日；实际开、竣工时间：2002年4月1日2002年7月20日。出口施工支洞计划开、竣工时间：2002年6月1日2002年12月31日；实际开、竣工时间：2002年5月30日2002年12月20日。洞身计划开、竣工时间：2002年8月1日2003年12月31日；实际开、竣工时间：20
5、02年7月20日2003年11月30日。两条渐变段上半部的开挖及支护月平均开挖强度5000 m/月；洞身I层开挖支护平均强度56 m/月， II层开挖支护平均强度78 m/月，III层开挖支护平均强度166.26 m/月；F7断层段开挖支护平均强度28 m/月。2 施工支洞布置由于导流洞进出口工作面受上部干扰较大，前期无法施工，经业主监理统一协调安排在上、下游各设一施工支洞进入主洞进行施工。进口施工支洞为进入导流洞进口段上层工作面的施工支洞，全长339.899米，与1#、2#导流洞相交于导1#0+54及导2#0+85桩号；下层支洞长277.16米，与1#、2#导流洞相交于导1#0+135.26
6、6及导2#0+166.2613桩号；出口上支洞总长837.543米，与1#、2#导流洞相交于导1#0+793.76及导2#0+861.613桩号；下支洞长163.628，与1#、2#导流洞相交于导1#0+755.76及导2#0+823.613桩号。3 洞身开挖支护施工3.1施工总程序 洞身自上而下分三层进行开挖支护。层开挖考虑到开挖机械性能及支护施工的需要，确定开挖高度约为89.55m；层开挖高度为10.5 m；层主要为保护层开挖，开挖高度1.73.15m。单洞开挖施工程序依次为层层层。层开挖支护完成后进行层开挖，层开挖支护完成后进行层开挖。各层均利用施工支洞进入主洞后分别向上、下游进行平行作
7、业，其中从上层施工支洞进入完成导流洞洞身层开挖支护；利用下层施工支洞在主洞内向上、下游升坡10%至层底面，完成导流洞洞身层开挖支护；从下层施工支洞进入导流洞底部进行层的开挖支护。3.2 施工队伍配置 进、出口各配置一个开挖队伍，每个开挖队各设一个台车钻爆班、一个手风钻钻爆班和一个支护班。3.3常规洞段开挖支护施工 常规洞段共1386米，占导流隧洞洞身开挖总开挖段长的75.4%。3.3.1施工程序常规洞段即I、II、III类围岩段横断面开挖程序见图1：1)洞身第层开挖施工程序：中导洞超前贯通后进行周边扩挖，初期支护滞后30米进行，与后循环开挖平行作业，类围岩视危岩情况及时进行局部支护。2)洞身第
8、层开挖施工程序：边墙用手风钻预裂4.5m，中部液压潜孔钻垂直钻孔梯段爆破。初期支护滞后30米进行，与后循环开挖平行作业，类围岩视危岩情况及时进行随机支护。3)洞身第层开挖施工程序：两侧边墙手风钻预裂到底，层采用手风钻及凿岩台车分半开挖，底部光爆，初期支护滞后30米进行，与后循环开挖平行作业，类围岩视危岩情况进行随机支护。 3.3.2 施工方法1#、2#导流洞层导洞开挖采用两台三臂台车进行两个工作面的开挖，其余工作面开挖采用手风钻开挖。层扩挖主要采用两台台车进行开挖，部分采用人工在三层平台架上810台手风钻钻爆。层开挖各工作面采用手风钻造4.5m深预裂孔超前爆破，液压潜孔钻梯段拉槽先行贯通后用凿
9、岩台车进行两端保护层水平扩挖，周边光爆。层开挖采用手风钻两边墙预裂到设计底板高程，凿岩台车及手风钻水平扩挖，底部光爆，出碴采用3m3 侧卸装载机配15t及20t自卸车运输。层及层开挖出碴主要采用3m3 侧卸装载机配15t及20t自卸车运输。层开挖出碴采用4m3 正铲配15t及20t自卸车运输为主，辅以3m3 侧卸装载机配15t及20t自卸车运输。洞身支护以凿岩台车造孔为主、砼喷射台车湿喷工艺进行喷锚施工；安装锚杆采用人工配合凿岩台车进行，挂网采用人工在平台车上进行。3.4 一般不良地质段开挖支护施工 小湾导流隧洞分布有一条级断层（F7），4条级断层为F11、F5、F19、F23，还有若干分属级
10、结构面的小断层、挤压面和节理组。实际施工中除F7断层、进出口不良地质带采用特殊施工方法施工外，其余小断层带开挖支护均采用与常规洞段大致同一种方法施工，不同之处是：小断层带开挖时层中导洞开挖时顶拱喷护5cm厚C20进行支护，层扩挖及、层保护层开挖后立即素喷5cm混凝土封闭岩面，部分系统锚杆及时跟进，剩余支护适时跟进。3.5 F7断层开挖支护施工 导1#0+1600+237及导2#0+2150+287范围为F7断层出露洞段，F7破碎岩带总宽约25.2米，其中主裂面有4个，总宽约0.5m2m，由断层泥、糜棱岩组成，其余为碎裂岩、碎块岩等，结构紧密。顺断层影响带一般具弱透水性，为地下水赋存及运移通道，
11、沿影响带常有集中滴水现象。F7断层部位开挖断面为20.523.35的城门洞型，F7段层破碎带纵向开挖程序与一般洞段开挖相适应分三层开挖：第一层开挖高度9.70m，第二层开挖高度10.5米，第三层开挖高度3.15米。3.5.1 F7断层层开挖支护施工1）施工思路及原理采用新奥法施工理论为指导：“短进尺、弱爆破、少扰动，紧封闭，勤量测”。利用三臂凿岩台车和砼喷车等大型机械设备实现了断层部位I层全断面一次开挖、及时支护、快速循环的先进施工工艺。关键之一：开挖后要及时对周边围岩及掌子面实施一层35cm的素砼封闭，以形成初期简单的柔性支护环，同时抑制围岩的进一步风化，增长围岩的自稳时间。利用掌子面的素喷
12、封闭措施，保持开挖掌子面与洞轴线大致垂直，以方便了大型机械作业，加快循环进度。关键之二：素喷后要及时打设一定数量的系统锚杆，尽早发挥其悬吊及支承拱作用，进一步的加强围岩的稳定，同时快速的利用反铲配合人工进行工字钢拱架的安装，系统喷混凝土跟进；剩余的系统锚杆适时打设。2）施工程序顶拱及边墙超前锚杆施工全断面开挖进尺0.51m初喷5cm钢纤维砼支护，掌子面周边2m范围内素喷5cm厚C20砼封闭初期支护锚杆及钢拱架固定锚杆施工安装钢拱架分层喷钢纤维砼至设计厚度剩余系统锚杆支护3）主要支护参数及施工方法a超前支护顶拱超前支护主断层带采用32自进式中空注浆锚杆，长4.5m，环向间距0.5m，外插角515
13、，排距2m；断层影响带顶拱超前支护使用25砂浆锚杆。边墙超前支护采用32砂浆锚杆，长4.5m，主断层带间距1m，断层影响带间距2m，外插角2530，排距3m。b系统支护F7断层带的系统支护采用I20a工字钢拱架，其中主断层带的间距为50cm，断层影响带的间距为80cm。工字钢拱架加工制作及安装方便快捷，易于及时支护跟进；同时由于F7断层跨度超过20m，使用工字钢拱架仍具备一定的柔性。系统锚杆主要采用6m长、32的砂浆锚杆（部分锚杆长度为9m）；间排距主断层带为1m1m，断层影响带为1.5m1.5m；主断层带造孔比较困难部分采用32自进式锚杆代替砂浆锚杆。F7断层范围内边顶拱均喷25cm厚C25
14、钢纤维砼。c主要施工方法F7断层的施工，超前支护钻孔主要采用三臂凿岩台车、自进式锚杆灌浆采用注浆机；开挖主要采用三臂台车钻孔；支护以多臂凿岩台车造孔为主、砼喷射台车湿喷工艺进行喷锚施工；工字钢拱架的制作采用液压型钢弯曲机。3.5.1 F7断层下部开挖支护施工为保证上下游交通畅通并确保施工安全，F7二层开挖分为两小层并分半施工，三层开挖分半施工。半幅开挖支护完毕后再开挖另一半。各层施工程序为：边墙超前锚杆水平钻进2m素喷5cm钢纤维砼封闭部分系统锚杆及锁脚锚杆打设钢拱架接腿分层复喷到位剩余系统锚杆打设（适时进行）。开挖采用凿岩台车水平钻进，周边密孔小药量光爆，排炮进尺1m，每排炮后及时喷护5cm
15、钢纤维砼封闭岩面，抑制岩体进一步风化剥落；开挖35m后进行一次系统支护，实际施工中由于边墙超挖较大，喷砼施工难以实施，采用同标号钢纤维砼现浇，以加快支护进度。 3.6 渐变段开挖支护施工 1#、2#导流洞进口渐变段长均为30m，相应桩号范围均为导0+000导0+030，渐变段底板为水平段。开挖断面尺寸从洞口0+0.00桩号25.425.2m渐变到0+030桩号20.423.2m的城门洞形断面；渐变段边、顶拱进行系统锚杆+I20a工字钢拱架+25cm钢纤维砼一次支护。渐变段主要分布少量弱风化和卸荷岩体，围岩岩性主要为黑云花岗片麻岩（MV-1）夹少量片岩，块状和次块状岩体，IV级结构面的小断层（f
16、）和挤压面（gm）较发育，主要有四组节理相互切割，围岩多具微透水性，属IV类围岩，围岩稳定性较差；加之渐变段最大开挖跨度达25.4米，且顶部大部分平直，未形成拱；所以开挖成洞稳定问题较突出；为此，渐变段施工中应采取有效垂直加固措施，防止洞顶塌落，隧洞开挖严格按“新奥法”工艺施工，开挖钻爆按照“先支护（强支护）、短进尺、弱爆破、少扰动，快封闭，勤量测”的原则施工，以确保围岩成洞稳定及施工安全。3.6.1 开挖前的垂直加固方案开挖支护施工开始之前必须完成以下超前加固工作:1）由于渐变段所处位置岩石破碎，IV级结构面较为发育，多组节理相互切割，围岩自稳性较差，为有效的稳定开挖面，拟对1#2#导流洞渐
17、变段洞顶部位EL.1036平台布置6排辐射灌浆孔进行固结灌浆，孔径110mm，灌浆采用孔口循环，全孔一次进行。2）由于渐变段跨度大，大半部分顶部平直，仅两侧起拱，开挖后围岩难以自稳，所以顶部除了灌浆加固外，拟采用悬吊锚筋桩从上部将洞顶拉住，具体方法如下：灌浆前每个孔内先置入25m长332锚筋桩，然后再进行孔口循环灌浆。3）增加水平支护：在洞口顶部开挖线以上1m外增设2排长度18m的332环向锚筋桩，间排距33m，矩型布置，伸入弱风化底界内。渐变段开挖前围岩超前加固方案见图3。3.6.2 渐变段的开挖支护方案渐变段I层开挖方案采用44小导洞超前，洞口10m大跨度段分两半分别进行开挖支护，其余20
18、m段全断面一次扩挖到位。渐变段的支护参数与F7断层近似，采用自进式超前锚杆、工字钢拱架、钢纤维砼；施工方法也与F7断层近似。在实际开挖过程中，开挖下部时，收敛观测资料显示2#洞右边墙变位较大较快，发现后及时在整个2#洞右边墙增加了125KN级9m长预应力锚杆支护，间排距11m，有效抑制了边墙的进一步变形。预应力锚杆采用特制水泥卷，锚固段采用快凝型水泥卷，自由段采用慢凝型水泥卷；锚固段和自由段药卷式注浆体一次注入，锚杆安装完毕后7.58.5小时内进行张拉，施工工艺简单，施工速度快，同时药卷式注浆容易保证注浆饱满度。3.7 导流洞出口开挖支护施工 导流隧洞出口穿过f19断层，并受f23断层影响，结
19、构面较为发育，地质条件较差，施工中采取下列有效措施：1）1洞出口12m段及2#洞出口20m段由洞挖改为槽挖，将f23断层切除，二次衬砌支护改为明拱。2）1#洞出口30m段采用地质钻在洞内沿顶拱造斜孔进行灌浆固结岩体。3）导流隧洞出口30m段采用22m小导洞超前贯通，摸清隧洞准确的地质状况。4）均采用超前锚杆、钢支撑及超前锚杆支护，开挖方法与F7断层近似。5）出口5m段自外向内分半开挖支护，开挖前洞脸设双排预应力锚杆锁口，洞脸边坡布六排锚筋桩及4排1000KN级系统支护。6）出口30m段洞内系统支护均由原设计砂浆锚杆改为9m预应力锚杆。4 结语小湾水电站导流隧洞开挖支护分采用“新奥法”施工，安全
20、、快速的穿越了F7断层、进口大断面渐变段不良地质段、出口不良地质段。导流隧洞分三层开挖支护，第一层采用台车和手风钻开挖；第二层采用手风钻进行上部预裂、潜孔钻中部拉槽、凿岩台车水平进行保护层开挖；第三层采用手风钻进行周边预裂、凿岩台车及手风钻开挖；施工质量得到了有效控制，1#洞平均超挖为0.204cm，2#洞平均超挖为0.182cm。导流隧洞施工期观测结果表明：1#、2#导流隧洞围岩变形观测测值呈收敛状态，没有突变现象发生；锚杆应力受力较好，观测结果稳定；声波测试表明，导流隧洞开挖时，爆破参数控制较好，对围岩松驰圈影响范围较小。说明小湾导流隧洞开挖支护方案是科学的。/Porganization
21、system and working mode, the selection of a number of municipal strengthening group to build innovation and strengthen the organization of the basic level organizations advanced model.(seven) the manual work of the Communist Youth League Organization published and League branch of manual work, to pr
22、omote the use of two manuals in the citys organizations at various levels. The county committee, directly under the group (work) is under the jurisdiction of grassroots League and group (total) using branch ratio shall not be less than 70%.Three, to further strengthen the groups leadership and team
23、building(a) to strengthen the leagues leadership at all levels of construction. Continue to do a good job of municipal Party Committee Organization Department on the strengthening of the Communist Youth League cadres management opinions implementation. To promote the group counties (autonomous count
24、ies, cities) Commission and city directly under the group (workers) appointed to carry out the Five team building activities. Improve the League Association Department working mechanism. Conscientiously fulfill the duties of CO, combined with the city group directly under (the) Committee of the gene
25、ral election and the adjustment, actively jointly with the unit where the party organization department good group leadership selection with the work. Do a good job in municipal Party committee assistant committee leadership and leading cadres of the annual assessment work, adhere to and improve the
26、 assistant secretary of the Communist Youth League talk system group To weave individual conversation and collective conversation, to strengthen the committees of all levels, the Standing Committee of the Standing Committee, the establishment of a sound system of central group learning, the system o
27、f investigation and study, the system of important issues and the reporting system.(two) to strengthen the work of education and training of cadres to conscientiously implement the Central Committee. On the implementation of grassroots cadres training project and opinions on carrying out the mission
28、 municipal CYL Cadres training project implementation opinions, full implementation of the project of the City Youth League cadres training education. Focus on the county grassroots cadres and workers focused on training, the new school system vocational training League cadres, for the Municipal Org
29、anization Department jointly held the third session of the Communist Youth League system training cadres in party. Focusing on the construction of new socialist countryside, strengthening village cadres and rural construction team group member of the young team, the county organizations at various l
30、evels throughout the year is expected to train 100 00 rural grassroots cadres, plans to train 1000 village secretary of the village Party branch.(three) actively promote grassroots cadres election work. Under the unified leadership of the party organization, to strengthen grassroots organizations di
31、rect work, standardize the election work rules and procedures, in the designated candidate, open competition to democratically elected branch secretary at the same time, actively and steadily the development of Township, streets and other grassroots organizations in the direct election of the pilot
32、work, on the basis of summarizing the experience and gradually expand the scope of the pilot, and gradually formed a set of measures and cadres election system.(four) to strengthen the cadres testing exercise. To study the development of XX city from 2006 to 2008 cadres testing exercise planning. To
33、 select outstanding cadres to the central mission in Beijing, Shanghai, Guangzhou and other central organs and sending work in developed areas. With the Central Committee the implementation of the western region and ethnic minorities cadres training plan . To carry out the eighth batch of municipal
34、organs attachment cadre management, selection, training work. The outstanding cadres to start the National Development Bank XX branch testing exercise.(five) to strengthen the group construction. The main position to play the role of Youth League cadre education and training as the city, in accordan
35、ce with the requirements of post training, further curriculum scientifically and rationally, adopt arrangement menu course, basic theory includes group work, focus, hot and difficult issues, to enhance the content and practice; to strengthen the construction of teaching staff, the integration of tea
36、chers, establish a quality teacher training team, establish and implement course evaluation system; take delivery of training to the countryside, on-site training, and increase the rural grassroots cadres training efforts.Four, efforts to strengthen the work of young talent(a) to tenth XX young 54 m
37、edal in recognition of the publicity, and actively explore the XX youth service. 54 Medal of institutionalization, standardization and socialization mechanism. Give full play to the XX award in recognition of 54 youth medal Association, Youth Award winner in the 54 chapter, investigation activities.
38、 Who won the Youth Service medal, dedication to the society to create conditions, build the stage. During the 54, named in recognition of the tenth XX young 54 medal. The association of XX editing of young talent , the exchange of information and communication platform for the XX of outstanding youn
39、g talents.(two) the establishment of municipal Party committee of young talent information database. In accordance with the feasible, effective, classification management, implement step by step principle, the establishment of municipal Party committee of youth talent database; guiding organizations
40、 at various levels generally established the young talent database, construction of city, county (directly under the Communist Youth League), grassroots organizations three young talent information database the relevant information collection system, and gradually establish the citys young people, t
41、he Communist Youth League youth talent information network, provide information platform for young talent resource development.Five, take effective measures to strengthen the mission management(a) to strengthen the mission management work. Strengthen the dues collection and management, continue to a
42、dhere to the dues collection regularly reporting system, the annual comprehensive award in recognition of the tour and the tour one vote veto system audit system. Do statistical work in the group. The group service award in recognition of the advanced units, standardization, promoting group manageme
43、nt work institutionalized.(two) to strengthen the organization of research and information exchange efforts. Grassroots carry out research, efforts to form a number of theoretical results. Make full use of the network carrier, to explore the establishment of electronic group service system, promote
44、the work of Communist Youth League information.Attachment 4:XX municipal Party Committee Propaganda Department of the Communist Youth League work pointsIn 2006, the Communist Youth League propaganda ideological work XX to Deng Xiaoping theory and the important thought of Three Represents as guidance
45、, study and implement the partys sixteen and the spirit of the the fifth Plenary Session of the 16th CPC Central Committee implementation of the eight plenary session of the two committee, the citys cultural work conference, the Propaganda Department of the meeting and the the fourth Plenary Session
46、 of the 15th CPC Central Committee permanent mission spirit, closely around 11th Five-Year XX the goal of full implementation of Scientific Outlook on Development, emancipating the mind, seeking truth from facts, keep pace with the times, close to reality, close to life, close to the young, persever
47、e grasp orientation, grasping deepening, grasping construction innovation, further improve the groups propaganda and ideological work ability, unity To guide the majority of members of the youth to achieve the 11th Five-Year planning tasks, the overall construction of a well-off society, building a
48、socialist harmonious society to make new contributions.One, adhere to the Three Represents important thought and Scientific Outlook on Development education to guide the youth, to further strengthen the ideological and political education of youth(a) armed with youth science theory. Unremittingly with Deng Xiaoping theory and the important
