沉管基槽水下炸礁高精度控制技术

Technology for high-precision control of underwater reef blasting in foundation trench for immersed tubes

大连湾海底隧道建设工程采用水下炸礁爆破工艺进行沉管基槽开挖工作。爆破施工具有炸礁方量大,爆层厚度厚,施工难度大、精度要求高等特点。为保障爆破施工的精度满足设计施工要求,开展一系列水下炸礁爆破试验,确定了爆破施工工艺和参数,通过监测手段验证了爆破施工方案的合理性。基于压力和振动监测数据,分析爆破施工对周围环境的影响。此外,还测试了气泡帷幕、减震帘及泡沫板对爆破冲击波的消压效果。通过综合分析3种方法的消压能力和可行性,确定采用气泡帷幕法对沉管结构实施保护。

Underwater reef blasting is used for excavation of the foundation trench for the immersed tubes for Dalian Bay Subsea Tunnel.Construction blasting is characterized by large volume of reef blasting,great thickness of rock layer to blast,high construction difficulty and high accuracy requirements.In order to ensure that the accuracy of blasting meets the design and construction requirements,a series of underwater reef blasting experiments were performed to determine the blasting process and parameters,and the reasonableness of the blasting method was verified by monitoring the blasting experiments.Based on the measured data of pressure and vibration produced by blasting,the impact of blasting on the surrounding environment was analyzed.In addition,the effect of bubble curtains,shock-absorbing curtains and foam boards on pressure dissipation of blasting shock waves was tested and measured.Through a comprehensive analysis of the pressure dissipation capability and feasibility of the above three methods,the bubble curtain method was adopted to protect the immersed tube structure.