青岛地铁近距离交叠隧道施工.

1、热烈祝贺热烈祝贺第八届海峡两岸隧道与第八届海峡两岸隧道与地下工程学术及技术研讨地下工程学术及技术研讨会召开！会召开！青岛地铁近距离交叠隧道施工青岛地铁近距离交叠隧道施工数值模拟与变形控制研究数值模拟与变形控制研究王渭明山东科技大学E-mail：提纲提纲1、工程背景2、研究方案与技术路线3、研究内容与成果4、结论1 1、工程背景n青岛地铁规划待建的地铁线为5条约115里，其中的交叠工程有20处(自身交叠13)。13处处2 2、研究方案与技术路线、研究方案与技术路线3 3、主要研究内容与成果、主要研究内容与成果3.13.1、交叠隧道主影响因素正交数值分析、交叠隧道主影响因素正交数值分析3.23.2

2、、既有隧道衬砌计算模型、既有隧道衬砌计算模型3.33.3、青岛交叠隧道变形规律研究、青岛交叠隧道变形规律研究3.43.4、交叠隧道变形特征与控制方法研究、交叠隧道变形特征与控制方法研究3.13.1、主影响因素正交数值分析、主影响因素正交数值分析3.1.1 因素、水平、指标因素、水平、指标埋深 H净距 h围岩参数E、C、岩层表土层新线隧道既有隧道开挖方向地表拱顶最大沉降量拱底最大沉降量拱顶最大下沉坡度对拱底最大下沉坡度地表最大沉降量塑性破坏区体积拱顶最大拉应力拱顶最大拉应力 指标指标FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN U

3、SAStep 3014 Model Perspective23:10:17 Mon Mar 24 2008Center: X: -3.553e-015 Y: 0.000e+000 Z: -6.500e+000Rotation: X: 20.000 Y: 0.000 Z: 50.000Dist: 3.112e+002Mag.: 1.95Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: Block Grouptunnel_2#_tun_1tunnel_2#_tun_2tunnel_2#_tun_3tunnel_2#_tun_4tu

4、nnel_1#_tun_1tunnel_1#_tun_2tunnel_1#_tun_3tunnel_1#_tun_4Axes LinestyleXYZ3.1.2 模拟的实现既有线路隧道既有线路隧道下部新建隧道下部新建隧道模型交叠模型交叠区加密段区加密段FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 14655 Model Perspective16:54:32 Tue Mar 25 2008Center: X: -2.269e+001 Y: 3.525e+000 Z: -8.810e+000Rotation: X:

5、 30.956 Y: 359.401 Z: 35.482Dist: 2.772e+003Mag.: 43.4Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: SEL Geometry Magfac = 0.000e+000SEL Geometry Magfac = 0.000e+000Block Grouptunnel_1#_liner_2tunnel_1#_liner_3Block Grouptunnel_1#_liner_1Surface Magfac = 0.000e+000SEL Geometry Magfac = 0

6、.000e+000SEL Geometry Magfac = 0.000e+000钢筋砼支护实体单元模拟锚杆支护cable结构单元模拟初喷砼支护shell结构单元模拟开挖面初喷砼支护shell结构单元模拟隧道未开挖段3.1.3 研究结论研究结论拱顶拱顶最大沉最大沉降量降量E C h H 地表地表最大沉最大沉降量降量E C H h 拱底拱底最大沉最大沉降量降量E h H C 塑性塑性破坏区破坏区体积体积 C h E H 拱顶拱顶最大下最大下沉坡度沉坡度E C h H 拱顶拱顶最大拉最大拉应力应力E h C H 对拱对拱底最大底最大下沉坡下沉坡度度E h C H 拱顶拱顶最大拉最大拉应力应力E h

7、 C H （1 1）影响因子对考察指标的影响力排序）影响因子对考察指标的影响力排序 n既有隧道拱底变形槽与拱顶变形槽BBFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 54824 Model Perspective20:35:34 Sun Apr 20 2008Center: X: 6.453e-001 Y: -4.609e-001 Z: 6.380e+000Rotation: X: 356.579 Y: 0.000 Z: 0.144Dist: 3.113e+002Mag.: 8.53Ang.: 22.500Pla

8、ne Origin: X: 0.000e+000 Y: 1.000e-001 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Surface Plane: on Magfac = 0.000e+000AAA - AFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 54824 Model Perspective20:47:56 Sun Ap

9、r 20 2008Center: X: 7.231e+000 Y: -1.556e-001 Z: -9.008e+000Rotation: X: 270.000 Y: 359.745 Z: 90.000Dist: 3.767e+002Mag.: 2.59Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: Contour of SMax Magfac = 0.000e+000 Gradient Calculation-1.2770e+005 to -1.0000e+005-1.0000e+005 to -5.0000e+004-5

10、.0000e+004 to 0.0000e+000 0.0000e+000 to 5.0000e+004 5.0000e+004 to 1.0000e+005 1.0000e+005 to 1.5000e+005 1.5000e+005 to 2.0000e+005 2.0000e+005 to 2.1523e+005 Interval = 5.0e+004Axes LinestyleXYZFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 54824 Model Perspective21:04:35 Sun Apr

11、 20 2008Center: X: -4.632e+000 Y: -1.556e-001 Z: -9.008e+000Rotation: X: 270.000 Y: 359.745 Z: 270.000Dist: 3.767e+002Mag.: 2.59Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: Contour of SMax Magfac = 0.000e+000 Gradient Calculation-1.2770e+005 to -1.0000e+005-1.0000e+005 to -5.0000e+004-

12、5.0000e+004 to 0.0000e+000 0.0000e+000 to 5.0000e+004 5.0000e+004 to 1.0000e+005 1.0000e+005 to 1.5000e+005 1.5000e+005 to 2.0000e+005 2.0000e+005 to 2.1523e+005 Interval = 5.0e+004Axes LinestyleXYZFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 54824 Model Perspective21:02:39 Sun Ap

13、r 20 2008Center: X: 2.565e+000 Y: 1.207e+000 Z: -9.021e+000Rotation: X: 90.000 Y: 0.480 Z: 90.000Dist: 6.067e+002Mag.: 3.81Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: Contour of SMax Magfac = 0.000e+000 Gradient Calculation-8.9905e+003 to 0.0000e+000 0.0000e+000 to 1.0000e+005 1.0000e

14、+005 to 2.0000e+005 2.0000e+005 to 3.0000e+005 3.0000e+005 to 4.0000e+005 4.0000e+005 to 5.0000e+005 5.0000e+005 to 5.4446e+005 Interval = 1.0e+005Axes LinestyleXYZB - BFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 54824 Model Perspective20:54:15 Sun Apr 20 2008Center: X: 2.565e+00

15、0 Y: 1.207e+000 Z: -9.021e+000Rotation: X: 90.000 Y: 0.480 Z: 270.000Dist: 6.067e+002Mag.: 3.81Ang.: 22.500Job Title: Overlapped Shield TunnelView Title: Contour of SMax Magfac = 0.000e+000 Gradient Calculation-8.9905e+003 to 0.0000e+000 0.0000e+000 to 1.0000e+005 1.0000e+005 to 2.0000e+005 2.0000e+

16、005 to 3.0000e+005 3.0000e+005 to 4.0000e+005 4.0000e+005 to 5.0000e+005 5.0000e+005 to 5.4446e+005 Interval = 1.0e+005Axes LinestyleXYZ既有隧道衬砌拱底拱顶最大拉应力云图既有隧道衬砌拱底拱顶最大拉应力云图（2 2）新隧道开挖引起既有隧道衬砌）新隧道开挖引起既有隧道衬砌拱底最大沉降量的回归公式拱底最大沉降量的回归公式1xH350tanxEC2xh12312233 122212320.771261940.5068414-11.85241448-0.10239599

17、6-0.1341451740.0286143040.00974783-0.0311126180.881466945-0.000535166Sxxxx xx xx xxxx拱底式中：式中：建立模型建立模型 弹性地基梁模型，假设梁底面与地基表面始终紧密相贴，即地基的沉陷或隆起与梁的挠度处处相等 新线隧道既有隧道衬砌弹性梁模型3.2、既有隧道衬砌计算模型、既有隧道衬砌计算模型求解求解nAB段：可由初参数法求出nBC段：k=0 44zd yEIbdx432123424zbyxA xA xA xAEI32123326zbxA xA xAEI212(62)2zbMEIxA xAEI 1(6)zbQEIxA

18、EI nBC段边界条件：lB点 ：lC点 ：l对称：lO点（中点）：1ByS1B1CyS1CBCMMBCQQ OyS0O结论结论n其中: S1 、 分别为新隧道开挖引起的既有隧道衬砌拱底变形槽反弯点处的沉降量和最大坡度角。n为了防止衬砌开裂破坏，应该提前在既有隧道施工时，在衬砌变形槽反弯点处设置变形缝。2241(2 )(2 )32384zzbbSSllalaEIEI21(2 )8zbllaEI13.33.3、交叠隧道变形规律研究、交叠隧道变形规律研究n 近距离交叠隧道的开挖会对地层产生两次施工强扰动，进而会显著增大地表的变形，同时地面沉降区的变形形态也会发生复杂变化，从单条隧道开挖的地表沉降槽

19、向复杂的沉降漏斗转变。地表沉降漏斗的形成过程仿真模拟地表沉降漏斗的形成过程仿真模拟模拟数据分析模拟数据分析n先开挖下部隧道，后开挖上部隧道n先开挖上部隧道，后开挖上部隧道地表变形规律特征地表变形规律特征（1）下线隧道开挖时，地表最大沉降量位于两条隧道轴线交点、最大沉降量为19.13mm。（2）在下线、上线隧道同时开挖时，地表形成的最大不均匀沉降槽与上线隧道轴心斜交，角度基本呈42度、并偏向埋深较浅的隧道轴线。（3）上线隧道轴线方向最大水平位移出现在距下线隧道轴线两侧1.25倍隧道洞径处，下线隧道轴线方向最大水平位移出现在距上线隧道轴线两侧1倍隧道洞径处。地表最大水平位移出现在距交叠隧道轴线交点

20、12.7m处。(4)、先开挖下部隧道比先开挖上部隧道将产生更大的地表变形，而且地表沉降槽曲线的斜率也会增加(5)、如先开挖上部隧道，在开挖下部隧道时，上部隧道能够起到阻隔下部隧道开挖影响的作用，减少地表变形。n建议建议 首先开挖上部隧道，而后进行近距离下部隧道的开挖近距离交叠隧道围岩变形特征（近距离交叠隧道围岩变形特征（5 5点）点） (1)、两条隧道的塑性破坏区会相互联通已开挖隧道段开挖面未开挖隧道段既有隧道交叠隧道夹层假象平面开挖引起的沉降槽沉降槽范围沉降槽范围最大沉降量S（2）由于进入地层沉降槽的位置不同，导致既有隧道衬砌不同截面的变形不同从而引起不均匀变形。n（3）下部新线隧道穿越既有

21、隧道的施工过程中，由于横向不均匀变形使既有隧道拱角处将承受较大弯矩作用 FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 50621 Model Perspective20:54:24 Wed Apr 02 2008Center: X: -3.553e-015 Y: 0.000e+000 Z: 3.739e+000Rotation: X: 0.000 Y: 0.000 Z: 0.000Dist: 2.573e+002Mag.: 5.96Ang.: 22.500Plane Origin: X: 0.000e+000 Y

22、: 8.100e+000 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Grid Plane: on Magfac = 0.000e+000 LinestyleGrid Plane: on Magfac = 2.000e+002 Exaggerated Grid Distortion LinestyleFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN

23、USAStep 50621 Model Perspective20:55:14 Wed Apr 02 2008Center: X: -3.553e-015 Y: 0.000e+000 Z: 3.739e+000Rotation: X: 0.000 Y: 0.000 Z: 0.000Dist: 2.573e+002Mag.: 5.96Ang.: 22.500Plane Origin: X: 0.000e+000 Y: 1.000e-001 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title:

24、Overlapped Shield TunnelView Title: Grid Plane: on Magfac = 0.000e+000 LinestyleGrid Plane: on Magfac = 2.000e+002 Exaggerated Grid Distortion LinestyleFLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 50621 Model Perspective20:58:16 Wed Apr 02 2008Center: X: -3.553e-015 Y: 0.000e+000

25、Z: 3.739e+000Rotation: X: 0.000 Y: 0.000 Z: 0.000Dist: 2.573e+002Mag.: 5.96Ang.: 22.500Plane Origin: X: 0.000e+000 Y: 1.600e+001 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Grid Plane: on Magfac = 0.000e+000 LinestyleGrid Plane:

26、on Magfac = 2.000e+002 Exaggerated Grid Distortion Linestyle截面 1截面 3截面 2FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 44983 Model Perspective10:04:12 Tue Apr 08 2008Center: X: 3.842e-002 Y: -2.472e-001 Z: 4.702e+000Rotation: X: 357.507 Y: 0.000 Z: 0.289Dist: 2.830e+002Mag.: 12.7Ang

27、.: 22.500Plane Origin: X: 0.000e+000 Y: 9.001e+000 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Contour of SMax Plane: on Magfac = 0.000e+000 Gradient Calculation-1.6717e+005 to -1.0000e+005-1.0000e+005 to 0.0000e+000 0.0000e+000

28、to 1.0000e+005 1.0000e+005 to 2.0000e+005 2.0000e+005 to 3.0000e+005 3.0000e+005 to 4.0000e+005 4.0000e+005 to 5.0000e+005 5.0000e+005 to 6.0000e+005 6.0000e+005 to 7.0000e+005 7.0000e+005 to 8.0000e+005 8.0000e+005 to 8.2861e+005 Interval = 1.0e+005FLAC3D 3.00Itasca Consulting Group, Inc.Minneapoli

29、s, MN USAStep 44983 Model Perspective10:04:12 Tue Apr 08 2008Center: X: 3.842e-002 Y: -2.472e-001 Z: 4.702e+000Rotation: X: 357.507 Y: 0.000 Z: 0.289Dist: 2.830e+002Mag.: 12.7Ang.: 22.500Plane Origin: X: 0.000e+000 Y: 9.001e+000 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job

30、 Title: Overlapped Shield TunnelView Title: Contour of SMax Plane: on Magfac = 0.000e+000 Gradient Calculation-1.6717e+005 to -1.0000e+005-1.0000e+005 to 0.0000e+000 0.0000e+000 to 1.0000e+005 1.0000e+005 to 2.0000e+005 2.0000e+005 to 3.0000e+005 3.0000e+005 to 4.0000e+005 4.0000e+005 to 5.0000e+005

31、 5.0000e+005 to 6.0000e+005 6.0000e+005 to 7.0000e+005 7.0000e+005 to 8.0000e+005 8.0000e+005 to 8.2861e+005 Interval = 1.0e+005(4)既有隧道衬砌拱顶、拱角、直墙、拱底均承受拉应力，这些部位容易产生破坏 。(5)、施工中既有隧道衬砌拱角处将出现较大弯矩 FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 29580 Model Perspective19:28:15 Wed Apr 09 20

32、08Center: X: 1.076e-001 Y: -3.822e-001 Z: 4.069e+000Rotation: X: 356.603 Y: 0.000 Z: 0.024Dist: 2.573e+002Mag.: 8.48Ang.: 22.500Plane Origin: X: 0.000e+000 Y: 1.000e-001 Z: 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Contour of SMin

33、 Plane: on Magfac = 0.000e+000 Gradient Calculation-2.8725e+006 to -2.5000e+006-2.5000e+006 to -2.0000e+006-2.0000e+006 to -1.5000e+006-1.5000e+006 to -1.0000e+006-1.0000e+006 to -5.0000e+005-5.0000e+005 to 0.0000e+000 0.0000e+000 to 5.0000e+005 5.0000e+005 to 1.0000e+006 1.0000e+006 to 1.2650e+006

34、Interval = 5.0e+005FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USAStep 29580 Model Perspective19:28:15 Wed Apr 09 2008Center: X: 1.076e-001 Y: -3.822e-001 Z: 4.069e+000Rotation: X: 356.603 Y: 0.000 Z: 0.024Dist: 2.573e+002Mag.: 8.48Ang.: 22.500Plane Origin: X: 0.000e+000 Y: 1.000e-001 Z:

35、 0.000e+000Plane Normal: X: 0.000e+000 Y: 1.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Contour of SMin Plane: on Magfac = 0.000e+000 Gradient Calculation-2.8725e+006 to -2.5000e+006-2.5000e+006 to -2.0000e+006-2.0000e+006 to -1.5000e+006-1.5000e+006 to -1.0000e+006-1.0000e+

36、006 to -5.0000e+005-5.0000e+005 to 0.0000e+000 0.0000e+000 to 5.0000e+005 5.0000e+005 to 1.0000e+006 1.0000e+006 to 1.2650e+006 Interval = 5.0e+0053.43.4、交叠隧道变形控制、交叠隧道变形控制（1）选定了五种工程加固措施，通过模拟，研究它们的加固效果和加固特点，比较分析其变形特征、敏感性参数（表2和表3）。（）加长新线隧道衬砌拱角的锚杆长度 （ ）增加新线隧道初喷砼的厚度和标号 （ ）设置超前注浆小导管 （ ）在新线和既有隧道直墙底部设置锁脚锚管

37、 （ ）既有隧道拱底注浆加固 五种工程加固措施：表表 2 2不同加固措施的变形特征参数不同加固措施的变形特征参数表表3 3不同加固措施的变形特征参数相对不同加固措施的变形特征参数相对方案的增量方案的增量（2 2）建议加固方案）建议加固方案 方案方案1：加长拱角锚杆+增加初喷砼刚度+拱底注浆方案方案2：加长拱角锚杆+超前注浆小导管支护+锁角锚 管 通过对比，建议新线隧道施工时采用方案方案2表表4 4 建议方案交叠工程变形特征参数建议方案交叠工程变形特征参数(3)(3)开挖方案优化与控制参数开挖方案优化与控制参数n 采用方案2加固，对台阶法、双侧壁导洞法、CRD法等三种施工方法穿越穿越隧道的施工过

38、程进行了开挖模拟分析。给出了不同施工方法每开挖步所产生的拱顶沉降量和分步开挖的变形控制标准。提出了近距离隧道穿越既有隧道的建议施工方法和控制参数。开挖动态过程开挖动态过程现浇砼支护初喷砼支护锚杆第一步 模拟开挖上部台阶并支护第二步 模拟开挖中部核心土第三步 模拟开挖下台阶并初支护及现浇砼衬砌锁脚锚管初喷砼支护台阶法开挖断面网格划分第一步 模拟开挖左右导洞并支护第二步 模拟开挖中间上台阶并支护第三步 模拟开挖中间下台阶并初支护、拆除隔墙及二次现浇砼衬砌眼睛法开挖断面网格划分初喷砼支护锚杆锁脚锚管锁脚锚管初喷砼支护现浇砼支护钢支撑隔墙Beam模拟第一步 模拟开挖左上导洞并支护第二步 模拟开挖左下导

39、洞并支护CRD法开挖断面网格划分第三步 模拟开挖右上导洞并支护初喷砼支护锚杆锁脚锚管初喷砼支护中隔墙中隔墙临时仰拱第四步 模拟开挖右下台阶并初支护、拆除临时仰拱和中隔墙、二次现浇砼衬砌支护现浇砼支护开挖过程中地层与衬砌的动态变形特征参数开挖过程中地层与衬砌的动态变形特征参数表表5 三种开挖步距沉降量贡献百分比三种开挖步距沉降量贡献百分比3.24Hmm4.21Zmm =6.01弧度 3.11Hmm4.09Zmm =5.97弧度 2.89Hmm3.81Zmm =5.41弧度 FLAC3D 3.00Itasca Consulting Group, Inc.Minneapolis, MN USASte

40、p 26876 Model Perspective09:02:33 Sat Apr 26 2008Center: X: -2.030e-004 Y: -3.232e-001 Z: -3.500e+000Rotation: X: 0.000 Y: 0.000 Z: 90.072Dist: 3.767e+002Mag.: 2.9Ang.: 22.500Plane Origin: X: -2.410e+001 Y: 0.000e+000 Z: 0.000e+000Plane Normal: X: 1.000e+000 Y: 0.000e+000 Z: 0.000e+000Job Title: Overlapped Shield TunnelView Title: Block State Plane: onNoneshear-n shea