extremely close distance away from Yangtze River 4. Fine sandstone and silty clay
Method
2.1 Safety system design
Waterproofing
1. The cement paste tends to be washed
Drill four holes well-distributed around the excavation region, and then test the permeability of each hole.
<=1 m3/d
Drill to obtain four cores well-distributed around the excavation region, and then test the homogeneity of each core.
Uniformity
2.3 Safety control process
2.3.2 Freezing control
Layout of freezing holes
Workers are examining the freezing effect.
2.3 Safety control process
away by the flowing water, resulting in
poor reinforcement.
A high-pressure jet grouting
2. No significant waterproofing resd due to the close
Safety management in tunnel construction: Case study of Wuhan metro construction
in China
Author： MiroslawJ. Skibniewski Lieyun Ding, et al
Reporter: Wu Tong-gang Central South University
2.3.3 UCW removing control
Workers are cutting down the steel within UCW.
Items
Reinforced soil strength
Reinforced soil permeability
Reinforced soil homogeneity
Checking methods
Checking criteria
Drill to obtain two cores on each side deep into the >=1 Mpa excavation bottom five miles away from the tunnel axis, and then conduct the core test.
New words
Shaft: 通风井 Grouting: 灌浆，给…灌浆 High-pressure jet grouting piles(HJGP): 高压喷射灌浆柱 Silty clay: 粉质黏土 Tunnel boring machine(TBM): 隧道掘进机 Gush: 涌出 Double-spool: 双轴
Numerical simulation
ANSYS
Ground heterogeneity
Construction
methods
Soil structure interact-
ion
Nonlinear behavior of soils
2.3 Safety control process
2.3.1 Reinforcement control
1.3 Project profile
Wuhan Yangtze Metro Tunnel (WYMT)
Characteristics: 1. Double-spool tunnel connecting
two large cities 2. Two sets of ventilation shafts 3. A curve radius of 350m and an
proximity to the Yangtze River.
Lowering of water level method
Ground freezing
Reinforcing
2.1 Safety system design
2.2 Safety analysis
Systemic safety
Economic requirements
Disadvantages 1. Large scale 2. Long duration 3. Complex technical issues
1.2 Objective
The primary aims of this study were to investigate:
i Overall Process Safety Management (OPSM) in tunnel construction. ii A more reasonable solution for the waterproofing and reinforcing works. iii A real-time update of both environmental parameters and control measures.
PART 1 PART 2 PART 3 PART 4
Introduction Method Results
Conclusion
Outline
Introduction
1.1 Background
Shield tunneling technology
Advantages 1. High level of mechanization 2. Fast progression of tunneling works 3. Lesser environmental impact