基于滚刀破岩特性的岩石顶管迎面阻力计算模型

A calculation model for the head-on resistance of rock pipe jacking based on the rock breaking characteristics of the disc cutter

顶进力是顶管工程设计和施工中最重要的参数之一,顶进力计算的精确性将直接影响顶管的工程的成败。随着顶管施工工艺越来越多的应用于岩石地层,但鲜有关于岩石地层中顶管顶进力的计算模型。为了更加准确地计算岩石地层中的迎面阻力,假设掌子面稳定,通过分析岩石顶管机刀盘滚刀破岩机理、受力模型和影响规律,在此基础上推导出岩石地层顶管迎面阻力计算公式。结果表明:岩石顶管中,岩石抗压强度和抗剪强度以及顶管机滚刀切入深度直接决定了迎面阻力的大小,实测迎面阻力除个别点在计算值上下限以外,其余与公式预测值相一致,证明其具有适用性。

Jacking force is one of the most important parameters in the design and construction of pipe jacking.The accuracy of the jacking force will directly affect the success or failure of the pipe jacking project.Pipe jacking is increasingly applied to rock formations,but there are few calculation models for the jacking force in rock formations.To calculate the head-on resistance in the rock formation more accurately,a new calculation formula of the construction face resistance during pipe jacking is derived.The pipe jacking face is assumed to be stable;the rock pipe jacking force is analyzed by consideration of the rock breaking mechanism,force model and influence law of the rock pipe jacking machine cutter head hob.The results show that in rock pipe jacking,the compressive and shear strengths of the rock and the depth of the pipe jacking hob cut into the rock directly determine the value of the head-on resistance;after determining the appropriate hob spacing,the number of tools is not blindly increased;otherwise,the rock breaking effect of each hob will be affected.Moreover,the measured head-on resistance in engineering practice is consistent with the predicted value of the formula,which proves its applicability.