基于多因素作用的非开挖HDD河床冲刷深度响应机制研究

Study on Response Mechanism of Scouring Depth of River Bed Based with Multi-factors in HDD

非开挖水平定向钻进(HDD)技术可极大减少管道敷设中的社会成本,目前被广泛应用于各类管线的暗挖施工中,尤其针对复杂地质环境下河流穿越更具有显著技术优势。由于管道敷设中对周围地层产生扰动破坏,从而改变上覆地层的物理力学特性,从而影响河床冲刷深度,对后期管道运营产生重要影响。本文在已有研究基础上,综合运用理论分析、室内实验和数学计算等方法,研究管道直径、敷设深度、地层类别、冲刷效率等因素共同作用下的冲刷深度响应机制。设计并建立了室内模型实验装置,能够实现上述因素的反演分析和参数获取;研究分析了扰动半径对理论冲刷深度的影响规律;拟构建基于扩孔直径、深度、轨迹、地层、流速、时间等因素的HDD 河床冲刷深度计算模式,为非开挖HDD 在河流穿越中的优化设计提供参考。

Trenchless horizontal directional drilling (HDD) technology can greatly reduce the social cost of pipeline laying. It is widely used in various types of pipeline excavation construction, especially for river crossing in complex geological environment. Due to the disturbance and destruction of surrounding strata during pipeline laying, the physical and mechanical properties of overlying strata are changed, which affects the scouring depth of riverbed and has an important impact on the later pipeline operation. On the basis of the existing research, the response mechanism of scour depth under the combined action of pipe diameter, laying depth, stratum type and scour efficiency is studied by means of theoretical analysis, laboratory experiments and mathematical calculation. An indoor model experiment device was designed and built to realize the inversion analysis and parameter acquisition of the above factors;the influence of disturbance radius on the theoretical scouring depth was studied and analyzed;a calculation model for the scouring depth of HDD riverbed based on the factors of enlargement diameter, depth, trajectory, stratum, velocity and time was proposed to provide reference for the optimal design of trenchless HDD in river crossing.