基于钻进参数的隧道掌子面围岩单轴抗压强度和弹性模量解析

Analysis of Uniaxial Compressive Strength and Elasticity Modulus of Tunnel Face Surrounding Rock Based on Drilling Parameters

随着隧道的埋深、断面尺寸、长度逐渐增大,隧道掌子面围岩的力学参数将直接影响掌子面的稳定性。传统的岩石室内试验方法人力、物力耗费较大,难以指导当前隧道智能化设计和施工,为此,提出了一种基于钻进参数的隧道掌子面围岩单轴抗压强度和弹性模量(Rb-E)解析方法。首先,从能量角度出发,提出了智能型凿岩台车冲击-推进-回转协同破岩过程中机械比能的计算公式。然后,采用数值模拟的方法,模拟智能型凿岩台车的破岩过程。通过动态分析方法,分析了单位体积的围岩在不同围岩单轴抗压强度、弹性模量条件下,钻进速度、围岩“密集单元”内能与围岩单轴抗压强度、弹性模量的动力响应规律。随后,利用能量法,建立了基于钻进参数的隧道掌子面围岩单轴抗压强度、弹性模量解析模型(DP-Rb-E)。最后,依托郑万高铁、宜兴联络线等钻爆法隧道工程开展了现场钻进试验和围岩力学参数测试,验证了该方法的可靠性。研究结果表明:在相同推进压力、冲击压力、回转速度条件下,围岩单轴抗压强度、弹性模量越大,钻进速度越慢,围岩“密集单元”的内能平均值越大;现场验证性试验结果表明,掌子面围岩单轴抗压强度解析结果与实测结果差异率为-5.52%~-20.89%,掌子面围岩弹性模量解析结果与实测结果差异率为-9.01%~-22.03%。

With burial depth,the section size and length of tunnels gradually increase,and the physical and mechanical parameters of the tunnel face surrounding the rock directly affect the tunnel face stability.The traditional rock laboratory test method consumes considerable manpower and material resources,making it challenging to guide the intelligent design and construction of tunnels.Based on drilling parameters,this study proposes an intelligent analysis method for the uniaxial compressive strength and elastic modulus(Rb-E)of rocks surrounding a tunnel face.First,a formula for calculating the mechanical specific energy during the combined impact-thrust-rotation rock-breaking process of a computer three-arm drilling jumbo is proposed from an energy perspective.Subsequently,a numerical simulation was conducted to simulate the rock-breaking process of the computer three-arm drilling jumbo.Using dynamic analysis methods,the drilling speed and dynamic response patterns of the energy inside the dense rock unit and the uniaxial compressive strength and elastic modulus of the surrounding rock per unit volume were analyzed under different uniaxial compressive strength and elastic modulus conditions of the surrounding rock.Subsequently,an analytical model of the uniaxial compressive strength and elastic modulus of the surrounding rock at the tunnel face based on drilling parameters(DP-Rb-E)was established using the energy method.Field drilling experiments and tests of the mechanical parameters of the surrounding rock were performed to verify the reliability of the method,relying on drilling and blasting method tunnel projects such as the Zhengwan high-speed railway and the Yixing liaison line.The results indicate that under the same conditions of thrust pressure,impact pressure,and rotational speed,the greater the uniaxial compressive strength and elastic modulus of the surrounding rock,the slower the drilling speed,and the higher the average internal energy of the dense units of the surrounding rock.The results of field experiments showed that the variation rate between the analytical results and the measured results of uniaxial compressive strength ranged from-5.52%to-20.89%,while the variation rate between the analytical results and the measured results of the elastic modulus ranged from-9.01%to-22.03%.