盐胀作用下埋地钢筋混凝土板受力性能试验研究

Experimental study on mechanical performance of buried reinforced concrete slab under salt⁃expansion

基于青海盐渍土地区埋地钢筋混凝土板现场模型试验,研究了考虑温度影响的盐渍土盐胀作用下钢筋混凝土板内及其表面的应力变化规律,并将其定义为“盐胀应力”。利用钢筋混凝土板内外应变监测结果,通过理论分析得出盐胀应力计算公式。基于Sum of sine函数模型将1年周期内盐胀应力的变化过程以及相对应的盐胀作用划分为发展阶段、稳定阶段、下降阶段3个阶段。其中发展阶段为每年10月至次年2月,温度变化范围为0~10℃,在该温度范围内,随着温度降低,盐胀应力不断增加,说明盐胀现象愈为强烈。对青海盐渍土地区的埋地结构物设计提出了建议,以期最大程度地减少盐渍土对埋地结构物的破坏。

Based on the field tests of buried reinforced concrete slab in the sulfate saline soil area in Qinghai,the stress variation law of the reinforced concrete slab and its surface under the salt expansion of saline soil considering the influence of temperature was studied,and it was defined as“salt⁃expansion stress”.Based on the internal and external strain monitoring results of reinforced concrete slab,the calculation method of salt expansion stress was obtained by theoretical analysis.Based on the sum of sine function model,the variation process of salt expansion stress in one year period and the corresponding salt expansion effect can be divided into three stages including development stage,stability stage and decline stage.The developing stage is from October of each year to February of the following year.The temperature range is between 0~10℃.Within this temperature range,as the temperature decreases,the salt⁃expansion stress continues to increase which demonstrates that the salt expands becomes more significant.Suggestions were put forward for the design of buried structures in the saline soil area of Qinghai Province,in order to minimize the damage of saline soil to buried structures.