盾构穿越江底断裂带技术措施与成本分析

Technical Measures and Cost Analysis for Shield Machines Crossing Riverbed Fault Zone

摘要:

泥水盾构穿越江底断裂带具有众多不可预见的施工风险，围岩极易产生崩塌、失稳等现象，进而会导致施工效率严重降低甚至引起掌子面持续坍塌，发生江面冒顶等重大事故。结合某城市轨道交通项目盾构区间穿越江底断裂带的实际工效，分析了所采取的设置应急处置系统、江中砂层加固、上软下硬边坡加固、应急填仓和江面注浆加固、滞排处置（包含设备改制、提升泥浆指标、开仓等）措施的合理性；另外，从合同概算外发生和原合同概算内未充分考虑这两方面进行成本分析，提出了索赔的针对性建议。

Abstract:

The slurry shield tunneling through riverbed fracture zones will have the numerous unpredictable construction risks. The surrounding rock is highly prone to collapse, instability and other phenomena, which can severely reduce the construction efficiency or even lead to the continuous face collapse and major accidents such as river surface blowout. Combined with the actual construction efficiency of shield machine crossing a riverbed fracture zone in an urban rail transit project, the rationality of the taken measures of establishing an emergency disposal system, reinforcing the sand layer in river, reinforcing the upper-soft lower-hard slopes, emergency filling and grouting the river surface reinforcement, and disposal of delayed excretion (including equipment modification, upgrading slurry parameters, and opening chamber) is analyzed. In addition, the cost analysis is conducted from two aspects of occurrence outside the contract budget estimate and insufficient consideration within the original contract budget estimate, and the targeted suggestions for claims are put forward.