应用于冻土路基的XPS保温板力学性能

Mechanical Properties of XPS Thermal Insulation Board Applied in Permafrost Embankment

为解决G214线共和—结古公路冻土路基施工过程中出现的挤塑式聚苯乙烯(XPS)保温板路基弯沉不达标及选材标准等问题,针对不同厂家生产的XPS保温板开展了单轴压缩试验,得到了其弹性模量和抗压强度,采用数值方法研究了XPS保温板弹性模量对路基弯沉的影响规律,分别计算了其在施工荷载和工后荷载条件下的应力分布。基于计算结果提出了能够满足冻土路基设计要求的XPS保温板力学性能指标。研究结果表明:路用XPS保温板应同时满足以下2个条件,即为满足路基弯沉的设计要求,弹性模量应大于45MPa,为满足施工期和工后运营期的强度要求,抗压强度不得小于500kPa。

In order to solve the problem that the deflection of XPS（extruded polystyrene）thermal-insulation embankment is substandard and the selection standard is uncertain in the permafrost embankment construction of G214 Gonghe-Jiegu Highway,a series of uniaxial compression tests were carried out based on XPS thermal insulation boards from different manufacturers,and the elastic modulus and compressive strength were obtained.The influence law of elastic modulus of XPS thermal insulation board on embankment deflection was investigated through numerical method.The stress distribution was calculated under construction load and operating load.Based on the calculation results,the mechanical indexes for XPS thermal insulation board that could satisfy permafrost embankment design were suggested.The results show that XPS thermal insulation board used for embankment should simultaneously satisfy two conditions,one is that elastic modulus of XPS should not be lower than 45 MPa to satisfy the deflection requirement,the other is that compressive strength should not be lower than 500 kPa to satisfy strength requirement during construction and operation.