盾构到达米埔竖井出洞方案20150725Plan of TBM breaking through(3)

广深港高铁深港连接隧道盾构出洞方案

through posture of TBM and advance adjustment plan. There are two attentions when consider through posture of TBM: on the one hand, the central axis deviation between current through tunnel and designed tunnel; on the other hand, the deviation of receiving portal position. Adjust properly on the base of designed tunnel central axis according to synthesize all the factors. The adjustment should finish step by step and not too much of each ring. 3.2.2 出洞地层加固 Ground reinforcement of breaking through

针对米埔竖井盾构出洞端头土层较软弱的特点，在盾构出洞前须对洞口土体进行地层加固处理，使之达到可以自立的状态，满足盾构破壁出洞的要求，同时满足盾构泥水体系平衡的建立。

Because the weak character of TBM breaking through end ground in Mai Po shaft, it is necessary to reinforce the ground of portal before TBM break through, let it strong enough to support itself, meets the requirements of TBM breaking through and establish the balance of TBM slurry system.

米埔出洞段地层采用高压旋喷桩加固的形式，加强土体的稳定。地层加固的旋喷桩采用桩径1800mm，桩间距为1300mm，高压旋喷加固体无侧限抗压强度不小于1.5MPa，渗透系数不大于1x10-7cm/s。旋喷桩应与工作井围护结构搭接200mm以上。高压旋喷桩加固区域沿隧道方向14m，垂直隧道方向为宽13.96m的区域，竖直方向为盾构隧道顶部加固高度5m、底部以下2.84m的区域。见下图。

Ground reinforcement of Mai Po breaking through section adopts high pressure rotary jet grouting pile, which make it stable. The diameter of rotary jet grouting pile is 1800mm, space between piles is 1300mm, the unconfined compressive strength of high pressure jet grouting with solid should not less than 1.5MPa, permeability coefficient should less than 1x10-7cm/s. Rotary jet grouting pile should connect with guardrail structure of work shaft more than 200mm. High pressure jet grouting pile reinforcement area is 14m along the tunnel direction, width of tunnel vertical direction is 13.96m, 5m above and 2.84m under the tunnel is the reinforcement area in vertical direction. Show in the figure below.

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广深港高铁深港连接隧道盾构出洞方案

图5 出洞地层旋喷桩加固平面图

Figure 5 The rotary jet grouting pile reinforcement floor plan of breaking through ground

图6 出洞地层旋喷桩加固剖面图

Figure 6 The rotary jet grouting pile reinforcement profile map of breaking through

ground

经过旋喷注浆加固后的土体，要求其有一定的自立性和稳定性，同时不能漏水、流沙，同时对端头加固地层要检查其土体强度和抗渗性能指标。土体强度通过钻芯取样测定，抗渗指标通过探孔取样，进行测水试验，通过试验结果确定其抗渗是否能够达到

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广深港高铁深港连接隧道盾构出洞方案

开洞门的要求。

The earth after rotary jet grouting reinforcement should have particular independence and stability; also cannot leak water or flow sand, check the soil strength and impermeability indicators of end ground consolidation. Measure soil strength with boring samples, explore hole for sample to measure permeability indicator, start water test, determine whether impermeability achieve the requirements to open portal according to the testing result. 3.2.3 洞门渗漏检测 Portal leakage test

盾构机出洞前需对洞门加固区域进行钻孔检测，以确认注浆加固的有效性，确保满足目标区域的渗透性需要，采用测量钻孔的流水量的方法来进行评估。

Portal reinforcement section should have boring test before TBM break through to make sure the effectiveness of grouting, ensure satisfactory permeability requirements for target areas, evaluate by measure water flow of boring.

每个洞门钻孔5个孔，分别在四周对称钻孔及中间部位钻孔，具体见下图所示： Drill 5 holes at each portal, and drill symmetrically around and in the center, details as below:

900010000渗漏检测钻孔渗漏检测钻孔62619035900330012002275365017251200550435135411486300渗漏检测钻孔渗漏检测钻孔92004142900011600

图7 渗漏检测钻孔位置图 Figure 7 Boring location plan of leakage check 1、在加固区域钻至预定深度 Drill to planned depth of reinforce area

采用凿岩机钻孔钻孔，钻孔直径45mm，钻进深度为超过连续墙2m，深度约为3.5m。 Drilling with rock drill machine, diameter of boring is 45mm, drilling depth 2m more

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广深港高铁深港连接隧道盾构出洞方案

than continuous wall, about 3.5m.

连续梁 图8 渗漏检测钻孔示意图 Figure 8 Boring diagram of leakage check 2、钻孔完成后测量渗水量 Measure water flow after drilling

钻孔完成后，插入导管，将水流引出，采用量杯等容器对渗水量进行测量。 After drilling is finish, insert pipe and draw water out, measure water flow with cups or other containers.

连续梁米埔竖井 图9 渗漏检测示意图 Figure 9 Leakage check diagram

3、测量地层及钻孔数据 Ground measurement and boring parameter

L cmL=1~2m 4.5cmTBM CLP011

广深港高铁深港连接隧道盾构出洞方案

钻孔直径 Boring diameter 盾构机地下水位深度 Underground water level of TBM 目标K值 Target K value 45mm P0 现场实际测量 P0 in-situ measurement k 28.3m 1×10-7m/s 按照以下公式计算 Calculate according the formula below

q= P0×4π×k×r0

or

k=q/ (P0×4π×r0)

q: 水流 Water flow (m3/sec) P0 : 水头差 Water head difference(m) r0 : 半径 Radius (√ （A/4π） ) (m) A : 表面区域 Surface area(πD2/4 + πDL) 例如 Example:

钻孔深度 Boring depth L L=2.0m 表面区域 Surface area A 2843.34cm2 半径 Radius r0 15.04 cm 水头差Water head difference P0 28.3m 渗透系数k Permeability coefficient K 10-7m/s 控制水流 Water flow control 321cc/min 计算过程：Calculation process

表面积surface area A=πDLπD2/4=3.1416*4.5*200+3.1416*4.5*4.5/4=2843.34 cm2

半径radius r0=√ （A/4π）=15.04 cm 目标值target value K=1×10-7m/s

控制流量control flow q≤ P0×4π×k×r≤0 5.3486 cm3/s≤321cc/min

通过测量的水流用于评估渗透系数K，如果K值低于1*10-7m/s，则说明注浆可以

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