g隧道超三前支护施工方法.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法序号支护类型施工方法

13、适用地层常用管径(mm）1管棚支护泥浆循环跟管钻进法松散粘土层、粉土层、淤泥层、沙层、回填土层、强风化岩层108、133、146、1592风动力跟管钻进法湿陷性黄土地层108、1593潜孔锤冲击成孔送管法弱中风化岩层、夹碎石强风化地层108、1594潜孔锤跟管钻进法卵石、碎石地层、卵石、碎石夹层及塌方现场108、127、1595管幕工法粘土层、沙层、淤泥层、回填层及强风化地层300-5006水平旋喷桩沙层、粘土层、粉细沙层、淤泥层、回填土层500-8007水平旋喷搅拌桩松散均匀的粘土层、粉细沙层、淤泥层、回填土层、富含水地层。500-10008冻结管施工淤泥层、流沙层等不稳定的含水地层89、1

14、08隧道开挖预支护的管棚法 一、管棚法的基本概念管棚工法是隧道开挖施工中用以防止掌子面坍塌并限制围岩变形的一种预支护手段。其主要原理是在隧道开挖之前，沿着隧道开挖轮廓线外的设定部位水平铺设钢管，并可以通过钢管向围岩注浆，对管棚周围的围岩进行加固，使管棚成为隧道后续开挖的防护伞（棚），达到安全施工的目的。管棚工法最早是作为山岭隧道施工的一种辅助方法，当隧道穿越破碎带、松散带、软弱地层、涌水、涌沙等地段时，管棚及其超前注浆对隧道的稳定起到了保护作用。管棚作为隧道顶部和边墙的超前预支护，可以有效防止掌子面的坍塌及地层过量变位，为隧道开挖提供安全保障。同时管棚施工快、安全性高，被认为是隧道施工中预防事

15、故的最有效、最合理的辅助措施之一。 二、隧道开挖预支护中采用管棚工法的原因 隧道开挖过程中，经常会遇到破碎带、松散带、软弱地层、涌水、涌沙等地段，在这类地质条件下进行开挖，如果不进行超前预支护，很容易出现坍塌情况，导致安全事故，不仅给相关企业造成经济损失，增加工程成本，而且极大地影响工程施工进度和施工质量。在隧道施工下穿既有线路或建筑物及河流、湖泊的开挖前，如果不进行超前预支护，很容易造成隧道上既有线路或建筑物的沉降以及河流、湖泊涌水而带来各种安全隐患。对于隧道施工过程中遇到上述情况时，早期隧道开挖时，主要采用插板法、小导管超前注浆法、浅层地表锚杆注浆加固法等进行超前预支护。但这几种支护工法都

16、有一些不足之处，就是支护范围和深度有限、加固强度不足，难以形成高强度支护整体，而且往往需要多个循环才能穿越需支护地层段，这样，不仅造成现场窝工、停工等情况，严重影响施工进度，而且有时其安全性也难以保证。 随着施工技术的不断改进，管棚工法得到了普遍的利用。特别是在导向跟管钻进等技术及多种新的施工工艺引入后，管棚施工的精度、打设长度、沉降控制及施工工效有了长足的发展。管棚工法是采用专用钻机将钢管沿隧道开挖轮廓线外一节一节地打入需支护的地层中的预定位置，然后进行注浆，通过浆液在围岩中的扩散，形成一个类似钢筋混凝土的拱形帷幕，从而达到支护开挖线外侧围岩的作用。 三、管棚工法的优点 管棚工法与前期超前预

17、支护工法相比，具有明显的优点，主要表现在以下几方面： （一）管棚工法所采用的钢管具有较高的钢性强度，而且管径相对较大，能够承载较大上部负荷。 （二）管棚工法的注浆可以使浆液在管棚钢管周围沿着土体缝隙进行扩散，不仅能起来加固土体的作用，而且还能起到一定的止水效果。 （三）管棚工法打设的钢管长度较大。目前施作管棚长度可以达到100m以上，这样可以大大地减少预支护循环次数，加快施工进度。（四）管棚工法能够通过专用导向仪精确控制管棚钢管铺设的轨迹线，确保管棚钢管按设计要求铺设，有利于控制隧道施工时的开挖量，减少施工成本。 （五）最新技术可以在软弱地层中高精度一次性打设数百米的管棚。 （六）管棚工法因为

18、采用大功率的水平定向钻机，施工效率比较高，大幅度地减少隧道开挖过程中辅助时间，提高施工效率。 四、管棚的作用 管棚工程在隧道开挖前的预支护中的作用主要有以下两方面： （一）提高围岩土体强度，提高开挖线拱部土体承载力，加固隧道围岩，确保隧道施工安全。在隧道穿越破碎带、松散带、软弱地层、涌水、涌沙等地段时，管棚的这种作用比较明显。（二）控制地表沉降。在隧道穿越既有线、下穿既有建筑物、构筑物等时，管棚的作用主要就是控制地表沉降，防止既有线路、建筑物、构筑物因隧道开挖而遭到破坏，确保既有线路、建筑物和构筑物的安全及隧道开挖的顺利进行。此种情况管棚的钢管直径可偏大（299）。 五、管棚工作的原理 管棚工

19、作的原理主要有两方面； （一）利用简支梁作用的原理；由于管棚的直径大、刚度大，同时又是较密排布置的，当钢管两端支撑梁的刚度达到足够大之后，开挖引起的变形量非常小，这时候管棚就相当于一道简支梁，阻隔隧道开挖时释放应力对围岩的作用。 （二）利用水泥浆液的流动性和围岩的裂缝或孔隙，使注入的水泥浆液能与土体进行粘合而形成一种类似混凝土的固结体，从而起到加固围岩土体的功能。对于含水较小的地层还能起到一定的止水效果。 六、管棚的设计参数 （一）管棚尺寸参数：管棚尺寸参数主要包括管棚的长度、钢管直径、钢管壁厚及隧道内工作室的尺寸参数。 1、管棚的长度一般为20-0m，特殊情况下，管棚打设长度可以达到100m

20、300m。 2、管棚直径常用的为89mm、108mm、159mm。 3、管棚壁厚一般为6mm，中间用同直径的壁厚1012mm钢管车丝扣连接。 4、隧道内施作管棚时工作室一般外扩30cm，当地层不允许时可用无工作室管棚施工法。5、在洞口施作管棚无需导向墙。 （二）管棚位置参数：管棚位置参数主要包括开孔位置、倾角、外插角和环向间距。 1、管棚中心位置距开挖线20-30cm，开孔位置偏差为2cm。 2、管棚倾角根据地质情况及隧道坡度确定。 3、外插角一般为0。至1。 4、环向间距根据现场地质条件、管棚管径确定，一般为25-40cm。 （三）管棚注浆参数：管棚注浆压力为0.8-1.2MPa，浆液配比按

21、0.8：1或1：1配制，注浆量根据管棚管径和管棚长度确定。 （四）管棚施工精度： 1、管棚打设倾角偏差根据管棚长度一般都能控制在0.5。以内，外插角控制在3以内。 2、管棚长度误差控制在30cm以内。 3、管棚施工过程中因为成管快，注浆能及时跟进，因此上覆地层沉降基本上为零沉降。 七、管棚适用条件及管棚施工实例（一）大多数隧道洞口属于浅埋和风化层，成洞较困难，采用管棚工法可以有效地解决洞口段的施工难题。 对于洞口的超前预支护，管棚长度一般为3040m左右，管径以108mm为主。通过管棚可以阻止洞口开挖时的应力释放。如图一所示为张石高速公路三甲村隧道进口管棚工程。该隧道开挖断面最大净宽为15m，

22、开挖断面面积为144m2进口处地质条件为砂卵石地层，地层松散，钻进时不易成孔。针对现场地质情况，采用了潜孔锤跟管钻进成管法施作108mm管棚，成管后进行注浆加固。 图一 张石高速公路三甲村隧道进口管棚工程 潜孔锤跟管钻进成管法是采用水平定向钻机通过锤头前端带有外锤头的潜孔锤冲击成管，外锤头通过丝扣跟管棚钢管连接，管棚打设到位后将外锤头与管棚钢管一同留在孔内，然后注浆加固围岩的管棚成管工法。 潜孔锤跟管钻进成管法适用于砂卵层、风化破碎带等不易成孔地层的管棚施工，要求用强度较高的无缝钢管作管棚钢管，每节钢管长度必须与钻杆配套，通过丝扣连接，便于接管加尺。管壁厚度不得小于6mm，管壁太薄时容易出现断

23、管的情况，影响管棚质量。管棚施工过程中要求现场供风压力不得低于6MPa，确保孔内钻渣排出干净，保证管棚质量。 施工精度控制：管棚打设到位后采用管棚导向仪进行钻孔测斜，根据测斜结果进一步分析确定钻孔钻进角度，并根据地层变化及时进行调整。 （二）隧道穿越破碎带、松散带、软弱、涌沙地层等地段时，为保证隧道开挖施工安全，也需要施作超前预支护管棚工程。管棚长度需要根据支护段长度确定，管径多为108mm-159mm。 图二 武广客运专线金沙洲隧道管棚工程 该隧道工程开挖时遇到的地质条件比较复杂，主要以松散风化岩为主，中间夹有松软的强风地层，局部存有空洞或较大岩层裂缝，在管棚施工时采用潜孔锤成孔后送管法施作

24、159mm管棚进行超前预支护，微扩工作面（20-30cm）,采用多次循环，一次打设米。 潜孔锤冲击成孔后送管法适用于风化岩层及软硬复合地层中，打设过程中要求采用风动力排渣，供风风压不得小于6MPa，保证出渣量。钻孔打设到位后退出钻杆和潜孔锤，然后采取锲形钻头将管棚钢管送到孔内进行围岩加固注浆。 图三 管棚工作面微扩剖面图 管棚精度控制：送管时需要用管棚导向仪进行钻孔测斜，发现偏差及时进行调整钻进角度（进孔角度）。 （三）隧道穿越既有线（如既有铁路、公路、高速公路、高速铁路等）、建筑物及构筑物等，管棚长度需要根据穿越长度设计管棚长度，管径根据现场地质条件及隧道上部覆土层厚度确定。如图 四、图五所

25、示郑西客运专线高桥隧道下穿既有铁路（同蒲铁路）的施工现场，该穿越隧道位于湿陷性黄土，主要发育垂直节理，极易下陷，而且设计为大断面开挖，开挖尺寸为15m13m(宽高)，断面面积达160多m2。为了控制地表沉降，避免影响既有铁路的正常运行，在隧道开挖前采用风循环跟管钻进法一次性施作159mm管棚100米。图六所示为郑西客运专线阌乡隧道下穿连霍高速公路（下穿段施作80m长159mm管棚共三个循环）。 图四 郑西客运专线高桥隧道下穿既有铁路的施工现场 风动力跟管钻进法适用于湿陷性黄土及干燥粉土地层，通过风压在6MPa以上的风力可以将钻渣排出，并在钻进的同时进行跟踪导向，控制钻孔偏差，确保管棚铺设精度。

26、 图五 郑西客运专线高桥隧道外景 图六 郑西客运专线阌乡隧道下穿连霍高速公路 （四）隧道开挖过程中的坍塌段超前预支护管棚，管棚长度一般都要一次性穿越坍塌段，并延长5-10m。管径根据现场地质条件及坍塌情况确定，一般为108mm-159mm。如图七为某隧道开挖时出现坍塌事故后抢险管棚工程。因在隧道开挖时出现了大范围的坍塌，导致隧道拱部大面积沉降，坍塌范围沿隧道开挖方向延长30m，致使隧道开挖无法继续进行。为了加固坍塌范围内土体，确保隧道开挖的继续，在该处采用水循环跟管钻进法施工长度为8m的108mm管棚。 图七 某隧道开挖时坍塌抢险管棚工程 水循环跟管钻进法适用于松散带、粘土层、沙层、淤泥层、回

27、填土及强风化地层等。采用水循环排渣、造浆护壁、冷却钻头，并在钻进的同时采用管棚导向仪进行跟踪定向，控制管棚铺设轨迹。 （五）隧道穿越富水地层中管棚超前预支护时，管棚长度应在富水段两端各延长10m左右，管径采用108mm或159mm。通过管棚注浆浆液的扩散，能够起到一定止水效果。针对这类地层，则采用水泥浆作为循环液的跟管钻进成管法施作管棚，然后进行注浆加固。如果采用水平旋喷桩进行超前预支护效果会更好，可以有效地实现止水和土体加固。图八为深圳地铁五号线西丽一号永久风道隧道管棚工程，采用水泥浆循环跟管定向钻进成管法施作108mm管棚。图九为深圳地铁五号线一号永久风道隧道水平旋喷桩工程。通过施作管棚和

28、水平旋喷桩，不仅控制了地表沉降，而且起到了止水效果，确保了隧道开挖的顺利进行。 图八 深圳地铁五号线西丽1号永久风道隧道管棚 图九 深圳地铁五号线西丽1号永久风道水平旋喷桩 （六）管幕工法是管棚工法的一种特例，主要适用于长距离下穿既有线超前预支护工程。如图十示为哈大高速铁路隧道下穿既有军用铁路专线鞍山隧道管幕工程。该隧道开挖断面尺寸13.4m11.3m，断面面积为160多m2，覆土层最小厚度为4m左右，管幕铺设精度要求较高，而且管径较大，为299mm无缝钢管。管幕施工过程必须控制地表沉降量，确保既有专用铁路线的正常运行及隧道开挖的顺利进行，因此只能先用无线导向仪进行导向孔施工，再采取挤扩拉管法

29、进行管幕钢管铺设，控制拉管过程中的出土量，防止地表沉降，最后进行注浆加固隧道上覆土层，实现超前预支护功能。 图十 哈大高速铁路鞍山隧道管幕工程Electricity lines, equipment inspections, found hidden in time for rectification, maintenance, and security. 9, do not use an open flame in the classroom, prohibit burning stove, lit candles, mosquito repellent, no smoking, and b

30、anning messy wiring. Without using any household appliances is not allowed. 10, live on campus faculty members, must lead by example, and educate families and children ready to fire. 11, household use of gas in schools, to master proper usage, pay attention to the leak-proof, explosion-proof, firepr

31、oof, closing valve after use to ensure security. 12, dining room must be qualified, and annual testing of pressure vessels, to regularly check, the canteen workers must be certified, strictly by operation operation, gas tank and stove safety distance of 1.5 meters, to prevent accidents. 13, the adve

32、rse consequences caused by ignoring fire safety regulations, will be punished, until investigated for legal responsibility. Song Lin Xiang Liu Jia ping elementary school March 2016 Xiang Liu Jia ping elementary school, pine slopes surrounding safety management system 1 teachers and students, the sur

33、rounding area of the school governance covers personal and food hygiene, cultural events and other aspects, integrated governance shall obtain wide support and full cooperation of the community. On the surrounding environment in schools should be closely monitored. 2, school work at the same time, s

34、hould pay attention to the safety management of school environment, should take the initiative to contact the district police station, the village Committee, Correctional Centre, Township government, business management and other departments to do a good job management. 3, teacher on duty with the e

35、xception of inspections in schools, should also pay attention to environmental inspections near the campus, found that the jobless migrants from rural areas, for example, harassment of students and a variety of accidents, according to different situations reported school officials or the police stat

36、ion in a timely manner, to protect the safety of students. 4, every day before school, teachers remind students, pay attention to traffic safety. 5, should educate students to respect social ethics, and various regulations, maintaining public order, and fight the bad guys, and grasp the correct ways

37、 and means of maintaining and improving students self-care ability. 6, the establishment of emergency rescue teams of teachers in schools, on high alert and deployed. Song Lin Xiang Liu Jia ping elementary school March 2016 song Lin Xiang Liu Jia ping primary school teachers and students organizatio

38、ns out of safety management system organization activities between teachers and students, to draw up a precise plan and security measures must be signed by the school officials to review the programme of activities agreed upon Correctional Center agreed to implement. Organization to the field relati

39、vely far or activities require approval by the Deputy Director of the Education Bureau in charge of security. 2, each activity should have a specific responsibility, pay attention to the persons age, physical match. Route 3, activities, location, field surveys should be carried out in advance. 4, ac

40、tivities for the means of transport should explain the situation to the school to comply with vehicle, safety requirements, before the line for repairs. 5, each activity must have security, emergency response plan for accidents. 6, picnics, hiking, picnic to pay attention to fire prevention, food poisoning, prevention of fall accidents 7, the activities near the rivers, reservoirs, no measures or do not meet the security requirements of the Organization and not let students into the water