Clay 粘土
EPB
Use of EPB injection materials
- 10-10 - 10-11 - 10-12
分布曲线粒径
粘土
fine
砂质粘土
midium coarse fine
砂
midium coarse
砂砾
粒径分布曲线: 粘土 淤泥 细砂 砂质粘土 粗砂 砂砾
粒径分布曲线
过滤分析 d > 0,1 mm
Adhesive tendency depending on plasticity and consistency
1,50 1,40 1,30
hard
Consistency Index IC
1,20 1,10 1,00 0,90 0,80 0,70 0,60 0,50 0,40 0,30 0
C
semihard
100 Clay Sand / S ilt y S and
90 Clay
80
Sand / S ilt y S and 70 370m
- 10
-1
Permeability Factor k (m/s)
- 10-1 - 10-2 - 10-3 - 10-4 - 10-5 - 10-6 - 10-7 - 10-8 10-9
Slurry
中细砂 Medium sand 细砂 Fine sand 含砂粘土 Sandy, silty clay 淤泥 Silt
F in e F in e Silt Med ium -Co ars e Sie ve Size F in e San d Med ium-Co ars e - F in e Gr ave l Med ium - Co ars e-
• Valencia • Madrid • Bangkok • Izmir • Singapore • Buenos Aires • Glatt Stollen • Socatop
Foam Injection Rate
Depending on the soil porosity n in the working chamber Soil type Sand pure graded Sand gravel wide graded Loam, till Clay hard Clay soft Porosity n 30% - 50% 25% - 35% 25% - 30% 20% - 35% 50% - 70%
泥水式
开胸式
复合式盾构
结构模式
土压平衡式
硬岩掘进机
泥水盾构 (单一隔板)
Tunnelvortriebstechni k
泥水盾构 (水量大的情况)
硬岩盾构
Tunnelvortriebstechni k
土压平衡 技术
土压平衡盾构
碴土的渗透性
Cobbles 卵石 Coarse Gravel 粗砂砾 Medium gravel 中细砂砾 Fine gravel 细砂砾 Coarse sand 粗砂
盾构机设计选型及依据
选择盾构机时，必须综合考虑，以获得经济、安 全、可靠的施工方法。盾构机机型是工程成功与否的 重要因素，选择时，必须注意以下几点： ① 适用于本工程围岩的机； ④ 后续设备、始发基地等施工设备能与盾构机的开挖 能力配套； ⑤ 工作环境。 为了减少辅助工法并保证施工安全可靠，选择能保 持开挖面稳定和适应围岩条件的盾构机型非常重要。
porosity
Types of water in the ground: 1 ground water 2 ground water table 3 confined kapillary water 4 free capillary water 5 adhesive water 6 pore angle water 7 air 8 grain with adsorbed water 9 seepage water
1 2 3 4 5
TBM Shield
1. Control station - main control panel 2. Mixing tank 3. Regulating pump 4. Polymer mixing tank 5. Pump 6. Reservoir tank 7. Feed pump 8. Compressor 9. Pneumatic regulating unit 10. Tank 11. Foam injection lance 12. Control station - main control panel 13. Injection pumps
Atterberg Limits
consistency: IC = (wP - w) / (wL - wP)
收缩极限： wS 液态极限： wL pulpy liquid
塑性极限： wP
可塑性范围 固体
semi solid
stiff
soft
Consistency index Water content
Consistency characteristics characteristics suspension squeezes through finger light ductile high ductile friable when rolling dried out, light coloured pulpy soft stiff semi solid solid plastic consistency liquid
Atterberg Limits
塑性指数: IP = (wL - wP)
常见碴土类型的塑性指数 碴土类型 条件 non-plastic low plastic good plastic high plastic depending
举例
Limit of IP
砂 淤泥 粘土 粘土 有机质土壤 膨润土
Index Properties of London Clay
EPB Injection Materials
Advantages of foam: • Low density • Optimum mixing with soil • Low percentage of chemical additives • Separation plants not necessary • Reduction of wear
Mixsh ield Op er atio n (Slurr y Mo de )
10 20 30 40 50 60 70 80 90 100
20 .0 60 ,0
0,001 0,002
0,006
0,02
0,06
0,2
0,6
2,0
6,0
Particle size in m m Geological Profile - Taipei
Foam Injection Rate
Flow rate foam (Q foam ) FIR = Flow rate soil (Q soil )
Qsoil = A face × vTBM Q foam = FIR × Qsoil
Foam Expansion Rate
Flow rate foam (Q foam ) FER = Flow rate liquid (Q liquid )
100% Liquid : Water Foaming agent Polymer
Foam Air Pressure
Depending on the working chamber pressure
Qair = ( FER − 1) × Qliquid × ( Pchamber + 1)
Foam Injection Schematic
EPB Operation
Face pressure controlled by: • • • Shield advance rate Screw conveyor discharge rate Muck pump discharge rate
EPB Face Support
• Separation plant not required • Slurry pumping system not required • Fine particle size materials easily handled
EPB Injection Materials
• Bentonite • Water • Polymers • Foam
EPB Injection Materials
• Reduce internal friction and cutting wheel torque • Reduce soil adhesion to metal of shield / cutting wheel • Reduce soil permeability
water content (W): plastic limit (PL): liquid limit (LL): plastic index (PI):
22% – 32% 20% – 33% 58% – 78% 33% – 49%
Consistency: (LL-W)/PI = 0,94 - 1,33 (stiff to hard)
密度
岩石
沙 粘土
淤泥
渗透性
恒定压力
渗出量
压力递减
渗透性
渗透性 参照 DIN 18130
条件 很低的渗透性 低渗透性 有渗透 高渗透性 非常高的渗透性 K值对照 (after Petermann) at 10°C 粗砂 细砂 超细砂 含砂粘土 粘土 灰质粘土
Atterberg Limits
粘结系数: IC = (wP - w) / (wL - wP)