A METHOD AND STRUCTURE TO ALLEVIATE THE EFFECT OF FROST HEAVE AROUND MANHOLES

摘要

Frost heave of pavements around sanitary and storm sewer manholes (10) and similar installations disposed in an under the pavement (12), is a major and costly problem in cold climates. As a result of the frost heave, a difference in level is created between the manhole cover (32) and the pavement (12) around it. Due to traffic, pavement cracks are formed around the manhole (10) necessitating costly repairs. It is proposed to alleviate the problem to a substantial degree by providing a frost-heave mitigating structure in a direct vicinity of a manhole (10) or a similar installation. To this effect, a heat-transfer zone (16) filled with large granulate is formed around the manhole (10) under the pavement (12), and openings (26) are formed in the wall (24) of the manhole (10) in a way enabling heat transfer between the warmer interior of the manhole (10) and the colder heat-transfer zone (16). The heat that flows to the zone warms up the surrounding soil in the vicinity of the zone thus preventing its freezing and consequently the frost heave approximately above the zone.