基于谷仓效应的砂卵石隧道围岩荷载计算研究

王明胜; 路军富; 李旻昊; 邓永刚

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铁道工程学报 ›› 2023, Vol. 40 ›› Issue (1) : 62-67.

长大干线:隧道工程

基于谷仓效应的砂卵石隧道围岩荷载计算研究

王明胜^1**, 路军富², 李旻昊², 邓永刚²

作者信息 +

Research on the Calculation of Tunnel Surrounding Rock Load in Sandy Cobble Soil Based on Barn Effect

WANG Mingsheng¹, LU Junfu², LI Minhao², DENG Yonggang²

Author information +

文章历史 +

摘要

研究目的:砂卵石围岩颗粒体系级配分布不均匀,颗粒间点对点接触,隧道施工过程中易引起围岩松散、失稳坍塌等突出问题。本文针对砂卵石围岩典型的颗粒物质特性,基于谷仓效应原理,采用颗粒物质离散元理论,探明砂卵石隧道围岩荷载计算方法,分析砂卵石土在不同细观组构下的细观力学行为,探究砂卵石颗粒级配对土体压力的影响特征,揭示隧道跨度对隧道围岩荷载的影响规律。
研究结论:(1)提出了用于计算砂卵石土竖向压力的修正Janssen计算公式,并确定了公式中重要系数转向比;(2)揭示了砂卵石颗粒级配对土体竖向压力与侧压力的影响规律,得到了砂卵石土体底部压力和侧压力的计算公式;(3)通过不同跨度的隧道模型模拟试验,提出了竖向荷载修正系数,使用修正系数法的砂卵石围岩荷载计算值与模拟计算的结果相近,验证了该公式计算的准确性;(4)建立了基于Janssen模型的砂卵石围岩荷载计算方法,可为砂卵石地层隧道精细化设计提供理论基础。

Abstract

Research purposes: The sandy cobble surrounding rock particle system has uneven gradation distribution and point-to-point contact between particles, which is easy to cause loose surrounding rock, instability collapse and other outstanding problems in tunnel construction process. According to the typical granular material characteristics of sandy cobble surrounding rock, based on the principle of granary effect, this paper uses the discrete element theory of granular material to explore the calculation method of surrounding rock load of sandy cobble tunnel. The meso-mechanical behavior of sandy cobble soil under different meso-structures is analyzed, and the influence of sandy cobble particle gradation on soil pressure is explored to reveal the influence law of tunnel span on tunnel surrounding rock load.
Research conclusions:(1) A modified Janssen formula for calculating vertical pressure of sandy cobble soil is proposed, and the steering ratio of important coefficient in the formula is determined. (2) The influence law of sandy cobble particle gradation on vertical pressure and lateral pressure of soil is revealed, and the calculation formulas of bottom pressure and lateral pressure of sandy cobble soil are obtained. (3) Through the simulation experiment of different span tunnel model, the vertical load correction coefficient is proposed. The load calculation value of sandy cobble surrounding rock by using the correction coefficient method is similar to the simulation calculation results, which verifies the accuracy of the formula calculation. (4) The load calculation method of sandy cobble surrounding rock based on Janssen model is established, which can provide theoretical basis for fine design of tunnel in sandy cobble stratum.

导出引用

王明胜, 路军富, 李旻昊, 等. 基于谷仓效应的砂卵石隧道围岩荷载计算研究[J]. 铁道工程学报, 2023, 40(1): 62-67

WANG Mingsheng, LU Junfu, LI Minhao, et al. Research on the Calculation of Tunnel Surrounding Rock Load in Sandy Cobble Soil Based on Barn Effect[J]. Journal of Railway Engineering Society, 2023, 40(1): 62-67

中图分类号： U455

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