滨海地区蚕食式清障与大口径管顶推施工工法.doc
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1、promotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming
2、 majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. To improve social governance, stimulating social organization, innovative and effective system of
3、preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of eco
4、logical system, using the system to protect the ecological environment. To improve natural resources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection manag
5、ement system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the peoples army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions
6、 and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. To deepen the adjustment of personnel system reform in the army, military policy a
7、nd system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve the partys leadership, give full play to the core role of the party commands the overall situation and coordinating all parties,
8、improving the partys leading water . Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-pings flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost a
9、ll political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however a
10、fter economic monopolized by powerful, vested interests grow, employers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat滨海地区蚕食式清障与大口径管件顶推施工工法1 前言滨海(靠近海边、沿海辞
11、海)地区顶管施工与陆地顶管施工相比,难点在于滨海饱和含水地层中流塑性的淤泥、构筑物、岩石、抛填石等障碍物,沉积层结构复杂,顶管推进过程可能发生障碍、渗漏、透水、土体变形、塌方等施工问题,严重时将导致工程陷于瘫痪或施工失败。我们运用“滨海地区蚕食式清障与大口径管件顶推施工技术”,顺利完成了汕头市海滨路中段综合改造工程W20-W21号井段排水干管分项工程的顶管施工,本工程的关键技术事项已通过了相关单位组织的鉴定验收。在此基础上,形成了滨海地区蚕食式清障与大口径管件顶推施工工法,本工法可为同类型项目施工提供借鉴。2 工法特点根据顶管线路设计中不可避免的滨海流塑性泥层、水下构筑物、岩石、抛填石等障碍物
12、分布情况,顶管机的刀盘采用排式钻孔导管、可在6090范围内转动,对障碍物进行多组钻刀、转换角度钻削,取出由环形钻刀钻削形成的圆柱状局部障碍物(下称障芯),依次推进;遇到金属障碍物可在顶管机机前仓内割除;遇到流塑性泥层施行冻固术使其凝结形成环管件范围凝固层,以利于断面钻削和管件外环泥层不致蠕动而发生顶管施工偏差。当遇到机头下沉或顶推方向偏差时可以纠偏。本工法在解决滨海复杂环境下顶管施工中形成,蚕食式清障,对顶管施工进度虽然较慢,但技术措施得当,解决了本工程项目难于施工的问题。3 适用范围3.1适用于滨海饱和含水地层、地下有钢筋混凝土构筑物、岩石、抛填石等坚硬障碍物的顶管施工。3.2适用于河道、坑
13、池、湖泊淤泥地层的顶管施工。3.3适用于有坚硬障碍物的陆地地层的顶管施工。3.4适用于顶推公称直径DN10001600、厚度1016mm的压力无缝钢管且两施工沉井间隔100m的顶管施工。4 工艺原理顶管机(图4-1)钻削刀盘传递顶管机对土层的压力和障碍物的内压力,以克服开钻面压力,在开钻时保持土体压力平衡和稳定;以顶管机的顶推速度(钻削量)为常量,螺旋输送机转速(排渣量)为变量进行控制,达到机仓内土、水压力与钻削面的压力保持平衡稳定,从而控制地表面的沉降或隆起;当钻削过程遇到坚硬障碍物时,通过可转换角度、带刀具导管孔的刀盘(图4-2),对钻面障碍物施行逐排蚕食式钻削弃除(图4-3);当遇到的障
14、碍物是流塑性泥层时,通过刀盘上各个刀具导管孔上的单向止水注浆阀注入冻结液,对钻面及其周围的泥层进行冻固止水,然后以钻刀进行逐排钻削取芯排障(图4-4),钻面一旦遇到金属材料,可在顶管机前舱安全地施行焰炬割除,以便于继续顶进,最后完成顶管施工。顶管机简图(图4-1)刀具导管孔布置(图4-2)刀具钻削排障原理(图4-3)障芯样品(图4-4)5 施工工艺流程及操作要点5.1工艺流程(图5-1) 清障顶管工艺流程(图5-1)5.2操作要点5.2.1施工准备。根据探测资料、施工设计方案做好施工前期完成工作井、接收井、井面雨棚、龙门吊、变压器。在工作井内安装顶管导轨、顶管机、电动千斤顶、抽水机(潜水泵)及
15、电源控制箱。备运料车、电焊机、氧割器、空压机、鼓风机、测量仪器等相应就位,施工人员着工装等。5.2.2顶管预备1)通过调整顶管导轨高度、实现顶管机面板中心(轴心)对准顶推管件中心,两中心的轴向偏差2mm。2)顶管机组与首节就位管件在导轨上的轴向水平偏差2mm。3)由于工作井直径8600mm,井底的顶管机组长4850mm,再加上液压千斤顶(零行程状态)及其支座占长1000mm,数值上只剩下2750mm长度的装管空间,因此在顶管机组上首次就位的管件长度应小于所剩长度空间250mm以上。故首节就位管件的长度定为2500mm。往后各节长度可以控制在6000mm范围内。4)测量顶管机后舱端面与管件端面接
16、触的平面误差,差值1mm为合格。5)检查管件前端与顶管机后舱对接口的密封是否可靠。6)启动液压站,检查各台千斤顶的顶推压力是否均匀,油缸行程是否同步,若出现偏差,需进行调整。5.2.3顶推过程的蚕食式清障。如遇坚硬障碍物应施行蚕食式清障作业。1)当顶管机前舱导孔钢管端接触障碍物时,按顺序自上而下逐个打开舱内导孔钢管的止水端盖,环形金钢刀具由导管孔装入,对障碍物进行逐排钻削,直至所接触的障碍物端面全部各点以刀具直径尺寸大小钻削排除。2)当钻削清障作业遇到钢筋、钢板等金属材料时,在其被钻削裸露状态下打开前舱门,并在鼓风机、空压机通风透气情况下,施行氧气火焰切割,并清除出舱。然后关闭舱门,以待下一步
17、的障碍切割。3)当打开某个导孔钢管止水端盖,发现有海泥渗透入顶管机前舱时,应即时逐个打开注浆阀,加注凝结液冻固土体。冻固待时应在2小时以上。对于整个顶推面是渗透淤泥的土体,还应打开刀盘外缘各个可调角度导管孔注浆阀,对其进行环状冻固,冻固的面积在半径方向应大于所顶管件半径的50cm以上,构成一个卧柱状凝固体,然后逐排钻削顶管范围内的凝固土,以便管件顶进,凝固的土体保凝时间应在完成钻削清障顶进后3小时以上。4)对于坚硬障碍物在管件端面范围内其垂直面积小于管件端面、尚有淤泥渗透的,其渗透端面采取局部凝固后,连同坚硬障碍物一起逐排钻削。5)因钻孔导管在机头刀盘的布点间仍有一定距离,钻头不可能将障碍物一
18、次性全部钻除,故在首次钻削清障后,还应转动刀盘一个角度,使导管孔对准未钻削的部位,以同样的方法钻削,余类推。6)钻削除去的障芯通过刀具导管排出,由打开前舱门,经中舱、后舱运上地面。5.2.4纠偏。在顶推过程中经测量发生偏离设计中心时,应采取纠偏措施,整个纠偏过程全部掌控在测量数值下操作。1)调整顶管机前舱顶推方向。按测量所得偏离中心数值,通过前舱4个纠正处理法兰口调整顶推方向,偏左则打开右法兰,偏右则打开左法兰,偏上和偏下打开法兰道理同此,以减少在管件相对面与土体的摩擦阻力,在顶推过程中实现纠偏。2)但前舱下沉偏离值较大,无法只以打开上法兰实现纠偏时,还需将上下两个法兰口同时开启,并在下部法兰
19、口处植入2支以上钢管桩(1005mm,桩长应小于前舱内径),以管桩和土体的摩擦阻力(需足够大)支撑机头前舱,不致其顶推过程中继续下沉,并在上部法兰打开情况下进行顶推,逐步纠偏,恢复到原顶进设计线路。5.2.5焊接管件。在顶进过程中,液压油缸的行程用尽而仍需继续顶进时,应视顶程加支钢管或加长块,实现顶推力的传递。每完成一节管件的顶推作业后,就应焊接下一节管件。1)对接管件端口采用“留间隙双面焊”,装配间隙为3mm。2)采用氩弧焊钢管自动电焊机,圈卷式连续电焊丝(H10Mn2),进行堆缝,焊缝堆满、连续,不产生气孔,焊缝高度1mm,高出部分应打磨平整。在全程多管焊接、焊缝偏高的情况下,顶推过程产生
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- 滨海 地区 蚕食 清障 口径 管顶推 施工
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