新建钻爆法隧道穿越既有输水隧洞实施方案

Implementation Scheme for New Borehole-blasting Tunnel Crossing Existing Water Conveyance Tunnel

摘要:

以某钻爆法市政隧道项目穿越既有输水隧洞为例，阐述了市政隧道实施方案中关于设计、施工、监测等方面的应对措施。市政隧道采用全包防水+CD法分部开挖，可有效减少隧道施工期及运营期对输水隧洞的变形影响，通过三维数值模拟，输水隧洞在隧道施工期最大隆起量为3.57 mm，在隧道运营期基本无变形；隧道施工过程中对洞室内坚硬岩体采用“水磨钻取芯+静态破碎”的施工方式，避免了爆破振动对输水隧洞结构的损伤；除加强隧道施工期的监控量测外，在隧道内布设了健康监测点，为隧道及输水隧洞的健康状态评估提供了可靠依据。

Abstract:

Taking a municipal tunnel project by the borehole-blasting method crossing the existing water conveyance tunnel as an example, the countermeasures in the design, construction, monitoring and other aspects in the implementation scheme of the municipal tunnel are expounded. The all-inclusive waterproof + CD method partial excavation is adopted for the municipal tunnel, which can effectively reduce the impact of the tunnel construction period and operation period on the deformation of the water conveyance tunnel. Through three-dimensional numerical simulation, the maximum uplift of the water conveyance tunnel during the tunnel construction is 3.57 mm, and there is basically no deformation in the tunnel operation period. The construction method of "water grinding drill coring + static state crushing" is adopted for the indoor hard rock mass in the tunnel construction process to avoid the damage of blasting vibration to the structure of the water conveyance tunnel. Besides the strengthening of the monitoring and measurement during tunnel construction, the health monitoring points are laid in the tunnel, which provides a reliable basis for the health assessment of the tunnel and the water conveyance tunnel.