隔热层对深季节冻土区涵底冻深的影响及其优化设计  

Influence of Thermal-protective Coating on the Culvert in Deep Seasonally Frozen Region and Its Optimized Design

作　　者：张蔚[1,2] 汪江红[3] 李先明 江聪[3] 牛永红[5] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]兰州大学土木工程与力学学院,甘肃兰州730000 [4]哈大铁路客运专线有限公司,辽宁沈阳110002 [5]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《铁道学报》2015年第12期96-105,共10页Journal of the China Railway Society

基　　金：国家自然科学基金(41071045);铁道部科技研究开发计划(Z2012-062);冻土工程国家重点实验室自主立项课题(SKLFSE-ZY-15)

摘　　要：在深季节冻土区,涵洞的存在使其基础的冻结深度大于天然场地冻结深度,前者约为后者的2倍,工程中一般将铺设隔热层作为解决方法。本文通过等效厚度换算法比较现阶段3种常用隔热材料的优缺点;以哈大高速铁路上的试验涵洞为原型,运用有限元分析方法,对深季节冻土区涵底有隔热层涵洞的温度场进行数值模拟;为检验隔热层效果,改变隔热层铺设的位置、方式和厚度,分别进行数值计算,了解各因素对涵底冻深的影响,得到适合涵洞基础的最佳隔热层铺设方案。结果表明:泡沫混凝土是涵底隔热层的理想材料,针对试验涵洞,应在基础最上端铺设厚度38cm、比基础宽10cm的泡沫混凝土作为隔热层,这样可以减少涵底最大冻结深度,满足寒区工程需要。In deep seasonally frozen region, the culvert changed the freezing process. The maximum depth of seasonal freezing in culvert foundation was about 2 times deeper than that in natural ground. In order to ease the situation, the measure of laying thermal-protective coating under the culvert is usually taken as a solution. In this paper, the advantages and disadvantages of three kinds of commonly used insulation materials were com- pared through the equivalent thickness conversion method. Based on the existing monitoring data of the cul- verts in Harbin to Dalian passenger dedicated line, a finite element model was established to simulate the tem- perature fields of the culverts with thermal-protective coating. To verify the effect of the thermal-protective coating, a numerical calculation was conducted respectively on different locations, modes and thickness of the thermal-protective coating to understand the influence of different conditions on the maximum frozen depth and to obtain the optimal laying scheme for culvert foundation. The results indicated that foam concrete is the ideal material for the thermal-protective coating, and the 38-cm-thick foam concrete should be laid on the top of the experimental culvert foundation as thermal-protective coating, which should be 10cm broader than the founda- tion. In this way, the maximum freezing depth under the culvert could be reduced, to meet the needs of con- struction in the cold region.

关 键 词：深季节冻土 涵洞 隔热层 材料 铺设方案 

分 类 号：U449.1[建筑科学—桥梁与隧道工程] TU471.7[交通运输工程—道路与铁道工程]