p隧道超前支护等施工方案.doc
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1、In order to ensure normal teaching order, protecting students healthy growth, ensuring that national (property) is not lost, to prevent or minimize the occurrence of safety accidents, follow the prevent, rescue each other, ensure safety and reduce losses principle, according to the local conditions,
2、 make the management system. 1, the principal is the responsibility of school safety, school security under the leadership of President security work leading group. The head teacher to the leadership team is responsible for, implementation of the accountability system. 2, school monthly student know
3、ledge about safety education, education should be diversified in the form every safety education for students of classes per week should be targeted. To carry on emergency issues dealing with education in General, self-help and mutual rescue knowledge. Emergency calls (such as 110, 119, 122, 120, an
4、d so on) use common sense in education. 3, the establishment of major accident reporting system. School students report major accident within an hour of education; student run and disappearances to report; report of the accident to a written report in triplicate, a correctional centre, a police stat
5、ion, a township peoples Government shall not conceal the accident. 4 week, teachers are on duty system, establish and improve the leadership values; strengthen the education, management of teaching activities in schools to ensure normal teaching order; responsible for school safety leadership always
6、 maintained close contact and district police stations, canvassing support from the police station on school safety and help. 5, strengthening teachers moral education, establish a dedicated love, improving education quality, observe the students psychological changes at any time and take preventive
7、 measures, no corporal punishment and covert corporal punishment on students, student out of the classroom, schools may not be. 6, units or departments use student Street propaganda or participate in the celebrations, as well as participating in other social work, without approval of the Correctiona
8、l Centre, school principals consent, without organization. Without the approval of relevant departments, may organize students to participate in fire fighting, disaster relief and so on. 7, schools should educate students to obey the school rules and regulations, on time, on time home to prevent acc
9、idents. 8, school to school inspections on a regular basis, found hidden in time, and in severe cases, it is hard to eliminate immediately closed, and reported to the local peoples Government, education, and rule of law section. 9, the school should always check the internal walls, retaining walls,
10、ponds, railings, handrails, doors, Windows, staircases and a variety of sports, extracurricular activities, facilities such as fire safety, infrastructure security, unsafe facility to immediately repair and demolition to ensure that teachers and students work, learn, live venues and facilities are s
11、afe and reliable. Song Lin Xiang Liu Jia ping elementary school March 2016 song Lin Xiang Liu Jia ping primary school fire safety systems to enhance fire safety, protection of public property and the life and property safety of teachers and students, school fire safety into day-to-day management, is
12、 developing the following fire safety system. 1, strengthen fire safety education of the whole school. According to the requirements of the Fire Services Act, so that everyone has of keeping fire control safety, protecting fire control facilities, fire prevention, reports of fire隧道超前支护施工方案一、施工准备1、导线
13、控制点、水平基点已布设,轴线放样和标高测量满足施工要求。2、供电、供水、供风及排水等辅助作业能满足施工需要。3、对施工队伍进行技术交底。4、根据现场施工组织情况,在施工前将所需材料提前运送至现场,所有进场材料均应经过试验室检验,并满足招投标文件对原材料各项指标的要求。二、施工方案本隧道超前支护措施设以下三种:108大管棚:隧道洞口段V级围岩,长度30m;42超前小导管:V级围岩,每环长度4.5m;22超前药卷锚杆:级围岩,每环长度4.5m。1、超前大管棚施工顺序:施作砼套拱钻机就位钻孔扫孔插入钢管孔口密封处理喷砼封闭管棚钢管注浆开挖及支护进入开挖支护循环1.1 大管棚参数1.1.1 钢管规格:
14、1086mm无缝钢管;1.1.2 钢管环向间距:40cm;1.1.3 管棚分段安装,每段长46米, 两段之间丝扣连接;1.1.4 导管上钻注浆孔,呈梅花型布置,导管尾部留有不钻孔的止浆段3.0米;1.1.5 钻孔的外插角:2度;1.1.6 注浆材料:采用M20水泥砂浆,注浆压力为12Mpa;1.1.7 与管棚配合使用的钢架采用三榀18型钢钢拱架,间距80cm;1.2 大管棚施工工艺超前大管棚施工工艺流程见下图“超前大管棚施工工艺流程图”。超前大管棚施工工艺流程图1.3 套拱施工待洞口边仰披开挖,支护到明洞初砌外轮廓线时,预留核心土,测量人员在坡面上定出中线拱顶高度,套拱位置线,横向十字线,然后
15、开挖两侧套拱位置的土体,边开挖边支护至边墙底高度以后,浆砌套拱基础,施做完后在明暗洞交界处架立三榀18型钢钢拱架,间距80cm,每榀钢架用拉杆拉紧,防止倾倒,必要时在拱顶拱腰坡面上两侧打锚杆,将最前面一榀拱架焊在锚杆上拉紧,套拱在明洞外廓线以外,紧贴掌子面施作。在钢支撑上以设计大管棚间距安装127mm,长2m的孔口导向钢管,必须用仪器仔细精确无误地检查其中线,方面与水平,确保导向良好,与管棚位置方向一至,用水泥纸或其他东西将孔口管封堵,防止浆液流入将孔口管堵塞,人工立模挡头板用钢筋拉杆拉紧,外模用铁线拉在衬砌拱架上,拱腰以下要用斜掌支于侧面上,完后浇注60cm厚的C25砼包裹钢支撑和导向管。套
16、拱完成后,喷射C20砼10cm厚封闭周围仰坡面,作为注浆时的止浆墙。见下图“管棚套拱安装图”。1.4 导管加工加工4米和6米两种规格的管;为使钢管对接,钢管两端分别加工成公、母丝扣,丝扣长15cm, 丝扣牙距5mm,管壁加工间距为2020 cm 的1016mm注浆孔,梅花型布置,以利于浆液通过管壁孔扩散到地层中。安装同孔导管时将4米管和6米管间隔装入孔中,相临两孔丝扣连接处相互错开。导管内插加劲钢筋笼,主筋4根,直径22mm,固定环采用42热轧无缝钢管制作,每段长4cm,间距150cm,与主筋之间焊接。见下图“管棚导管构造图”。1.5 测定孔位用全站仪精确测定钻孔孔位,并用红油漆标注在掌子面上
17、。1.6 导向管的安装为使大管棚安装在设计的位置,钻机施钻时要按设计的角度钻孔,故钻孔前需安装导向管,使得钻孔方位正确。1.7 搭建施钻平台施钻平台用钢管架由下向上、由两边至中间根据孔位依次搭成“井”字形,上面用木板铺平。要求钻机平台搭建必须牢固,钻机安放到平台上以后,要用钢丝绳紧固。1.8 钻机就位将钻机安放在施钻平台上,调整好高度、钻杆的倾角和方位角,然后将钻机牢固固定在施钻平台上,检查各管线和连接件是否正确。1.9 钻孔将钻头和钻杆穿过导向管,对准已作好标记的孔位孔心,慢慢开动钻机,注意钻孔应平直,孔底偏差距离小于钻孔的半径。用螺旋钻杆配三翼钻头,干式钻进成孔。钻孔直径:120125mm
18、;钻孔平面误差不大于50mm;孔斜控制措施:导向管导向;为了能顺利下管,成孔后再进行扫孔,顺通孔道。大管棚施工完成后,成伞形辐射状,详见下图:1.10 安装大管棚大管棚安装时用钻机顶进,钢管间为丝扣连接,用自由钳旋转拧紧,相邻两孔的钢管接头要相互错开。顶进钢管时要保证导管的倾角和方位角与钻孔钻杆前进的倾角和方位角一致。最好在钻完一个孔后不要移动钻机,立即将该孔的导管顶入孔内,安装好导管后,再移开钻机进行下一孔的钻进。1.11 注浆注浆采用M20水泥砂浆,前进式注浆,水泥砂浆注浆参数根据现场试验情况进行调整。注浆达到预定压力后,即停止注浆,关上止浆阀门,打开泄压阀,待管内压力降为0后,关上泄压阀
19、,同时将吸浆管放进旁边早已准备好的清水中,开动注浆机及时清洗管路。1.11.1 注浆要求 注浆前用清水试压管路,检查管路是否连接紧密,如有问题及时处理。 排气管要通到底,以防孔内压注空气浆液不能注到孔底。对于单孔在注浆结束后,迅速拔除注浆管,并立即用M20砂浆闭孔口止浆,是完成注浆的标志。1.12质量标准及注意事项1.12.1 孔位误差为50mm,角度误差为1度。1.12.2 钢管的打入的实际长度不得小于设计长度。1.12.3 做好注浆记录。1.12.4 注浆过程中,发现异常现象必须及时处理。主要技术措施: 注浆操作人员必须经过专门培训,并实行岗位责任制,在注浆前充分做好各项准备工作。 注浆前
20、,在洞外将管路全部接通,进行试压,试压可用清水进行。在试压时,如管路不通或接头有漏水现象,予以排除,保持管路系统各部件完好畅通。 注浆完毕后,清除管内浆液,用水泥砂浆紧密充填,以增强管棚的强度和刚度。认真清洗干净所有的机具设备,特别是搅拌机、注浆管、接头、阀门、贮浆桶等,以备下阶段注浆时使用。2、超前小导管超前小导管采用外径42mm,壁厚4mm,长450cm的热轧无缝钢管,钢管前端呈尖锥状;管壁四周钻注浆孔,孔径为8mm,孔间距10cm,呈梅花形布置,尾部30cm不钻注浆孔作为止浆段。钢管与衬砌中线平行,以外插角10 o打入拱部围岩;钢管环向间距50cm。小导管布置见下图“超前支护横断面布置图
21、”:2.1小导管加工小导管加工如下图所示。2.2 超前小导管施工工艺流程施工流程:测量放样钻孔清孔钢管插入封口注浆与钢架或锚杆焊接。见下图“超前小导管施工工艺流程图”。超前小导管施工工艺流程图2.3 施工方法2.3.1 测量放样按设计要求,在掌子面上准确画出本循环需施设的小导管孔位。2.3.2 钻孔小导管在打孔前,按设计要求划出小导管的位置,并标明清楚。采用凿岩风钻打孔,成孔直径53,孔口钻眼偏差小于50mm,孔眼长度大于小导管长度,然后将小导管打入,小导管打入后用高压风将小导管内砂石等吹出。小导管尾部置于钢架腹部,增加共同支护能力。小导管安装后用塑胶泥封堵导管外边的孔口及围岩裂隙。2.3.3
22、 钢管插入及孔口密封处理钢管由用钻机顶进,顶进钻孔长度不小于90%管长。钢管末端除焊上挡圈外,再用胶泥麻筋缠箍成楔形,以便钢管顶进孔后其外壁与孔岩壁间隙堵塞严密。钢管搭接长度不小于100cm,并与钢支撑焊接在一起。钢管顶进时,注意保护管口不受损变形,以便与注浆管路连接。2.3.4 小导管注浆注浆采用M20水泥砂浆,注浆材料满足下列要求:浆液的流动性好,易注入地层;固结后收缩小,具有良好的粘结力和较高的早期强度;结石体透水性低,抗渗性能好等。注浆前导管孔口应达到密闭标准,以防漏浆,然后采用注浆机注浆,注浆压力为0.51.0Mpa,一般按单管达到设计注浆量0.32m3作为结束标准,当注浆压力达至设
23、计终压不少于20分钟,进浆量仍达不到注浆终量时,便可结束注浆。注浆结束后,将管口封堵,以防浆液倒流管外。注浆过程中设专人做好记录。注浆结束后检查其效果,不合格者补注浆。2.4 小导管注浆异常处理串浆则采用多台泵同时注浆或堵塞串浆孔隔孔注浆;水泥浆液压力突然升高,则应关停注浆泵,进行注清水,待泵正常时再进行单液注浆;当注浆液量很大,压力长时间不升高时,则应调整浆液浓度及配合比,缩短凝胶时间,进行小量低压力注浆或间歇式注浆。2.5 小导管注浆量计算小导管注浆工程量可以按下式计算:式中:R浆液扩散半径,可按0.25m考虑L小导管长度岩体孔隙率K充填系数,为0.31.0,对粉粘土取较小值,对碎石土、砂
24、土取较大值。2.6 超前小导管支护质量保证措施2.6.1 小导管安装小导管间距根据围岩状况确定,采用单层小导管时,其间距为50cm; 前后排小导管错开布置,前后排小导管的搭接长度不小于100cm; 小导管外插角度根据注浆胶结拱厚度确定;小导管安装前,将工作面封闭严密,并正确测放出钻孔位置后方可施工。2.6.2 小导管注浆注浆前应喷射混凝土封闭作业面,防止漏浆,喷射混凝土不小于4cm; 注浆材料应根据地质条件、注浆目的和注浆工艺全面考虑,但确保满足下列要求:浆液流动性好,固结后收缩小,具有良好粘结力和较高早期强度,结石体透水性低,抗渗性能好。当有水侵蚀作用时,采用耐侵蚀材料;注浆过程中,注浆压力
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