水平透壁通风管增强封闭碎石路堤降温的累积效应  

Accumulative effect of cooling capability in air-tight crushed rock layer with horizontally embedded perforated ventilation pipes

作　　者：孙斌祥[1] 杨丽君[1] 王伟[1] 杨秋伟[1] 徐敩祖[1] 

机构地区：[1]绍兴文理学院土木工程系,浙江绍兴312000

出　　处：《岩土工程学报》2013年第S2期389-395,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41272345;40972203)

摘　　要：针对青藏高原高温冻土区采用的透壁通风管碎石公路路堤,进行了水平埋设透壁通风管封闭表面碎石路堤降温效果的室内试验,研究了负温通风透壁通风管增强其降温效果的累积效应。分析表明,除冷空气通过管壁小孔与通风管周围碎石区域孔隙空气循环产生的强迫对流降温作用外,负温通风透壁通风管封闭碎石试样还在上部碎石区域产生孔隙空气循环的自然对流降温效果。随着气温波动循环数的增加,碎石试样底部温度快速趋向负温,且其负温值不断降低。这种降温效果的累积效应能确保路堤及下土体冻结而有利于高温冻土区公路路堤的热稳定性。A crushed rock layer of highway embankment with a horizontally embedded perforated ventilation pipe is employed in warm permafrost regions of the Qinghai-Tibet Plateau. Laboratory experiments on the cooling capability in the air-tight crushed rock sample with a horizontally embedded perforated ventilation pipe are performed. The accumulative effect of cooling capability is analyzed. The analysis shows that the air-tight crushed rock embankment with a perforated ventilation pipe can enhance the forced convective cooling capability of the embankment base due to pore air motion in the crushed rock region near the ventilation pipe forming a pore air circulation in conjunction with the ambient cold air through the small holes in pipe wall, and improve the natural convection cooling capability due to pore air circulation occurring in the upper crushed rock region during the negative air temperature ventilating period. The temperatures in the lower crushed rock region quickly tend to negative values with the increase of air temperature fluctuating cycles. This accumulative effect of cooling capability may ensure the thermal stability of highway embankment in warm permafrost regions.

关 键 词：青藏公路 碎石路堤 透壁通风管 降温累积效应 

分 类 号：U416.12[交通运输工程—道路与铁道工程]