Creating a microclimate in underground structures
Building of buildings and constructions under the ground has its own characteristics, the complexity increases when the object is built in the conditions of permafrost.
This is due to the special properties of permafrost, which should be considered when designing industrial and civil objects. The existing recommendations in this area focused mainly on the preservation of permafrost, the creation of special conditions that hinder the development of their thawing and degradacii their physico-mechanical properties .
Practical implementation of these recommendations has led to widespread use in these climate zones pile foundations, subfield ventilated, etc. significantly reduce the heat ducts from the buildings to the ground, which prevents them from thawing.
However, the need to ensure public safety in cases of technological disasters, the requirements of bodies for civil defense and emergencies give the task of construction of underground structures, including in the conditions of permafrost, a particular specificity.
The existing experience of building such facilities shows that their operational reliability and durability is largely determined by the condition of microclimate, technical means of ensuring and linking the parameters of the microclimate conditions of preservation of permafrost.
In other words, the question of the duration of the existence of underground structures largely depends on the operational and thermal characteristics of enclosures and internal parameters of air and their consistency with the parameters of the soil.
The aim of this work is a brief analysis of the experience in construction of underground structures and technical tools that can be used to provide agreed terms on microclimate and soil condition makes it possible to save space.
with a natural microclimate
Apparently, domestic need was one of the first reasons that prompted people to use underground structures for the purpose of preservation of crops and livestock, including in the conditions of the Arctic.
Thanks J. Fourier it became known that the special thermal properties of the underground facilities – temperature-controlled microclimate occur because of the existence of a certain depth within a soil mass, the temperature of which is maintained approximately constant even though the presence of finite thermal conductivity of the layer.
Physically, the temperature distribution in the soil column is a non-stationary process due to daily and annual temperature fluctuations of the earth’s surface and, correspondingly, periodic inlet and outlet of heat from its surface. So depending on thermophysical characteristics of the soil, one should expect the existence of the depths at which these fluctuations are negligible compared to temperature changes on the surface.