Development of Designing Technology for Chilled Gas Pipeline Utilizing the Mechanical Properties of Frozen Soil and Ice Layer

冻结粘结强度试验冻结粘结强度试验是在轴对称冻结装置上进行的，对圆柱形试件的周边进行了约束，以给出管道与霜球之间边界处的约束正应力。通过改变管道中防冻液的温度，可以控制霜球的生长，并可以预期试件内部的应力分布以及边界处的正应力也会相应变化。通过7例不同约束条件的试验，观察了冻胶粘结强度的变化，结果表明，结果表明，界面正应力是影响冻胶粘结强度的重要因素之一，界面剪应力与相对位移的关系表现为非线性关系，正应力的作用和应力的大小提高了粘结的耐久性改进了分析应力计算模型，考虑了作用在管周上的约束应力变化对试件内部应力分布的影响。在此基础上，利用数值模拟的方法，成功地估算了界面正应力的大小及其对冻胶粘结强度的影响。该模型可扩展为多维评价模型，为设计提供实用模型。研究结果为建立冻胀作用下冷煤气管道的设计方法提供了基础性依据。

Adfreeze Bond Strength ExperimentAdfreeze Bond Strength Experiment was carried out by an axis-symmetric freezing apparatus with constraining the perimeter of the cylinder shaped specimen in order to give the constraining normal stress at the boundary between the pipe and frost bulb. By changing the temperature of the antifreeze flowing in the pipe, it can be possible to control the growth of the frost bulb and it can be expected that the internal stress distribution within the specimen as well as the normal stress at the boundary vary correspondently. Through 7 cases of the experiment with different constraining conditions, the change in adfreeze bond strength was observed.As a result, the normal stress at the boundary is confirmed as one of the most important factors for adfreeze bond strength and the relationship between shear stress and relative displacement shows nonlinear property due to the effect of the normal stress and the intensity of the stress enhance the durability in bonding.Modeling for Interactive Action between the Pipe and the Frost bulbThe analytical stress evaluation model was improved to consider the stress distribution within the specimen corresponding to the change in the constraining stress acting on the perimeter. Based on this model, it became possible to estimate the normal stress at the boundary and the effect of it on the adfreeze bond strength was successfully evaluated by the means of numerical approach. This model is thought to be expanded to multi-dimensional evaluation model as a practical model for design. It is convinced that fundamental findings for the establishment of designing method for chilled gas pipeline under frost heave action are obtained.