外界大气温度 meaning in English

outer atmospheric temperature

Thaw settlement cause negative friction . this paper base on the thought of " initiative cooling " , aim at three problems existing in common concrete pile used in frozen soil , a new type of pile is proposed to overcome the disadvantages of the classical pile used in frozen soil . pile body within active layer is fluted and refilled with porous materials such as gravels and ballasts , convection will be occur and then thermal exchange inside porous material in winter while only heat conduction exists in summer , as a result the soil around flutings will be cooled , so the top line of permafrost will be drive up
本文基于“主动冷却”地基的思想，以及针对冻土地区普通混凝土桩存在的三大问题，提出了一种新型桩的设计思路，运用数值仿真试验手段对其冷却机理与加固机理进行了系统研究，即在冻融活动层的深度范围内，在混凝土桩身的表面刻槽，修筑完时槽内填充碎石、块石等多孔介质，通过外界大气温度的自然波动下多孔介质在冬季时存在的对流换热机制，而在夏季只存在热传导，来达到主动冷却桩周冻土和抬升冻土上限的目的。