地下通道矩形顶管施工技术.ppt

《地下通道矩形顶管施工技术.ppt》由会员分享，可在线阅读，更多相关《地下通道矩形顶管施工技术.ppt（51页珍藏版）》请在沃文网上搜索。

1、Personal designed by Lijiezhi地下通道矩形顶管施工技术Personal designed by Lijiezhi一、矩形顶管机类型 刀盘类型 压力平衡模式Personal designed by Lijiezhi开敞式网格式Personal designed by Lijiezhi偏心刀排Personal designed by Lijiezhi大小刀盘组合Personal designed by Lijiezhi大刀盘、偏心刀排组合Personal designed by Lijiezhi小刀盘、偏心刀排组合Personal designed by Lijiezh

2、i行星刀盘（公转+自转）Personal designed by Lijiezhi行星刀盘组合Personal designed by Lijiezhi土压平衡式Personal designed by Lijiezhi泥水平衡式Personal designed by Lijiezhi二、场地要求及掘进过程场地要求：始发井 接收井掘进过程：始发 接收 Personal designed by Lijiezhi始发井场地1.4109密封环内衬结构围护结构旋喷桩始发井平面4.856.04顶管主机管片61m+主机+钢副环+千斤顶+反力台架11.5mPersonal designed by Liji

3、ezhi4.85顶管主机4.34管片4.3管片4.3管片4.3始发过程Personal designed by Lijiezhi接收井场地4.856.04顶管主机吊出井平面围护结构内衬结构972.076.11.4密封环2.071m+主机+1mPersonal designed by Lijiezhi4.85顶管主机4.34管片4.3管片4.3管片4.3管片4.3接收过程Personal designed by Lijiezhi三、端头加固加固目的：止渗漏 抵抗破桩后的土体压力加固方法：旋喷桩 搅拌桩+旋喷桩 注浆 素墙+旋喷常见问题：渗漏 完整性差 砂层问题 Personal designed

4、 by Lijiezhi始发井加固体厚度推荐加固体厚度：均质淤泥、粘土、残积土地层1.82.0米；复合含砂地层2.83.0米Personal designed by Lijiezhi接收井加固体厚度密封环加固体导轨2接收井纵剖面4.85顶管主机4.341预先破除围护结构时，厚度同始发井抵达后破除围护结构时，机壳切入加固体1米，厚度约1.8米Personal designed by Lijiezhi2.856.12.852.76端头加固纵剖面端头加固平面20.7密封环导轨旋喷桩密封环3旋喷桩加固区域旋喷桩加固Personal designed by Lijiezhi旋喷桩加固区域2.76密封环2

5、.856.1旋喷桩导轨密封环0.72端头加固平面端头加固纵剖面2.85搅拌桩搅拌桩加固区域搅拌桩+旋喷桩加固Personal designed by Lijiezhi2.74垂直注浆加固20.7密封环导轨导轨密封环0.7水平注浆加固2.74注浆加固（自稳性较好地层）Personal designed by Lijiezhi导轨密封环0.72端头加固纵剖面密封环端头加固平面素墙+旋喷桩加固素墙旋喷桩素墙旋喷桩核心问题：刀盘破混凝土能力低标号混凝土 一般只用于补救措施Personal designed by Lijiezhi常见问题1：渗漏问题描述：问题描述：加固效果差，加固体不连续，未达到止水效

6、果补救措施：补救措施：始发或到达前钻水平孔检验效果，有渗漏需采取注浆或补旋喷措施直至达到止水效果为止。Personal designed by Lijiezhi问题描述：问题描述：加固体与围护结构之间是止水薄弱环节，易形成渗水通道加强措施：加强措施：始发或到达前钻水平孔检验效果，有渗漏需采取注浆或补旋喷措施，并可在转交处增加旋喷桩，延长渗水路径。Personal designed by Lijiezhi常见问题2：加固体完整性良好Personal designed by Lijiezhi完整性差没有加固效果问题描述：问题描述：加固效果差，加固体不连续，可能起不到止水和抵抗土体压力的作用补救措施

7、：补救措施：始发或到达前钻垂直孔检验效果，完整性差时应采取补强措施温馨提示：温馨提示：操作手经验至关重要，关系到加固能否一步到位。补强措施费时费力，也很难达到预期效果可能强度过高Personal designed by Lijiezhi常见问题3：砂层问题4.85顶管主机4.34问题描述：问题描述：砂层因渗透性强，旋喷压力损失，难以达到加固效果；中粗砂层往往标贯值很高，搅拌桩难以实施等。加固效果往往出现两个极端：加固效果很差或强度过高（可达2030MPa）给掘进带来困难。措施：措施：1、选用双管旋喷桩；2、自外向内加固；3、加入惰性物质膨润土，既可以增加砂层抗渗性，防止旋喷压力损失，又可以防止

8、强度过高的问题。Personal designed by Lijiezhi四、其他辅助措施 千斤顶反力台 土体改良与管节减摩 止退装置 密封环 Personal designed by Lijiezhi千斤顶反力台4.856.04顶管主机保持千斤顶后靠背垂直流塑状等不良地层加固Personal designed by Lijiezhi土体改良土体改良砂性土排土不畅或造成砂层固结刀盘面板添加剂注入孔膨润土和发泡剂等管管节节减摩减摩减少土体与管道间摩阻力在管道外壁压注触变泥浆序号膨润土水纯碱CMC（CMS）乳化油配方12002503502.54.51.52.5配方2170100057触变泥浆配比表

9、（按公斤/立方米计）土体改良与管节减摩Personal designed by Lijiezhi止退装置Personal designed by Lijiezhi密封环Personal designed by Lijiezhi五、应急处理案例海珠广场站号通道刀具严重损毁应急处理文化公园站号通道端头渗漏应急处理Personal designed by Lijiezhi海珠广场站号通道刀具严重损毁应急处理Personal designed by Lijiezhi刀具损毁状况Personal designed by Lijiezhi接收井剖面2密封环4旋喷桩加固区域4.85顶管主机4.34管片4.3

10、2.5刀具损毁原因Personal designed by Lijiezhi号通道概况单管旋喷桩接收井加固平面双管旋喷桩密封环2.50密封环双管旋喷桩始发井加固平面2.50单管旋喷桩Personal designed by Lijiezhi车站结构始发井剖面42管片4.30.7密封环导轨管片4.3管片4.3管片4.3管片4.3管片4.3旋喷桩加固区域2.5Personal designed by Lijiezhi接收井剖面2密封环4旋喷桩加固区域4.85顶管主机4.34管片4.31.82.5Personal designed by Lijiezhi接收井剖面2密封环4旋喷桩加固区域1.82.4

11、9处理方案比选过程1 1、强行顶进、强行顶进 发现刀具严重损毁时，机壳距加固体约40cm，开仓风险巨大。强行顶进至机壳进入加固体，此阶段顶进约50cm，取出石块、部分损毁刀具。进入加固体后无法继续顶进。2 2、竖井方案、竖井方案 用竖井开挖方式去除加固体。因顶管机上方靠车道侧土体无法加固，未实施。3 3、矿山法方案、矿山法方案 用矿山法开挖方式去除加固体。因机壳切入加固体仅0.1米，仍有较大风险。工期长，管后泥浆固结对继续顶进不利。未实施。4 4、平衡出洞方案、平衡出洞方案 接收井回灌泥浆，启用铰接千斤顶，剪切破坏加固体，顶推洞身加固体出洞。辅助措施：地表取芯、水平取芯。最终实施方案。4.85

12、顶管主机4.34管片4.3Personal designed by Lijiezhi水中出洞出洞效果Personal designed by Lijiezhi处理实施细节1 1、连续墙破除、连续墙破除 连续墙分两次破除，第一次60cm，第二次20cm。第二次破除时自下而上。2 2、取芯降低抗剪强度、取芯降低抗剪强度 垂直取芯、水平取芯3 3、注浆孔预留、注浆孔预留 预埋注浆管，在破除连续墙和顶进过程中，如有渗漏时注浆止水。4 4、平衡泥浆、平衡泥浆 砂层顶标高+1米以下回填泥浆。其余灌水回填。5 5、管片背后注浆回填、管片背后注浆回填 注浆完成后方可抽出平衡泥浆。单管旋喷桩接收井加固平面双管旋

13、喷桩密封环2.50接收井剖面244.85顶管主机4.34管片4.31.82.49Personal designed by Lijiezhi教训与启示 1、元凶是“孤石”。地质资料显示人工填土层进入通道顶部，应分析是否有人工“孤石”的可能，或可以避免事故。2、操作人员在发现刀盘扭矩、声音异常时应立即停止掘进，处理“孤石”后再掘进，可以避免损失扩大。3、平衡出洞是控制地表沉降的最有效措施，建议条件具备的工点尽可能采用。接收井剖面2密封环4旋喷桩加固区域2.5Personal designed by Lijiezhi文化公园站号通道端头渗漏应急处理Personal designed by Lijie

14、zhi设计端头加固方案概况Personal designed by Lijiezhi渗漏情况Personal designed by Lijiezhi第一次：双管旋喷第一次：双管旋喷 靠端头连续墙旋喷深度14m实桩，其余为顶管4.3m高度范围上下各3m实桩（总深12m，实桩10.3m）。在旋喷桩加固完成后，连续墙水平探孔时有发现漏水漏砂现象。经过钻孔取样，砂层成桩不连续。第二次：袖阀管双液化学注浆第二次：袖阀管双液化学注浆 4排间距0.8m-1.0m。经探孔、抽芯检验，有一定的止水效果，但加固体整体性仍较差，连续墙破除过程仍有较大风险。补充加固过程Personal designed by Lijiezhi素连续墙方案Personal designed by Lijiezhi顶进过程遇到的问题始发井连续墙钢筋素混凝土连续墙原有加固体木桩吊出端地质钻杆Personal designed by Lijiezhi教训与启示 1、砂层加固效果难于保证，因慎重选择端头加固方式。本案原设计方案为搅拌桩为主，旋喷桩配合。因木桩原因改为全旋喷桩加固，应采取相应措施保证旋喷质量（见有关章节）。2、加固过程必须保质保量一次到位，之后的补救措施很难有效果。3、采用素连续墙加固需要验证刀盘适应性、控制混凝土强度。4、研究刀盘切削玻璃纤维筋的可能性。5、本案采用了平衡出洞方案，地面沉降控制效果良好。