Laserfiche WebLink
e <br /> � <br /> MINIMUM EMBEDMENT DEPTHS Bearing grades of all foundations subjected to freezing <br /> � temperatures must be embedded beneath ground surfaces for frost penetration protection. <br /> Minimum embedment depths are specified in State of Minnesota building codes or local building' <br /> ' codes. The greatest embedment depth of these codes should be used for protection. In general <br /> accordance with these codes, TABLE F lists recommended embedment depths for frost protection. <br /> � TABLE F FOUNDATION EMBEDMENT MINIMUM DEPTHS �"� <br /> SUBGRADE PERIMETER ALL FOUNDATIONS <br /> I BENEATH FOUDATIONS IN IN UNHEATED ALL FOUNDATIONS <br /> FOUNDATIONS HEqTED BUILDINGS BUILDINGS AND IN HEATED AREAS <br /> AND STRUCTURES STRUCTURES <br /> Well-drained ' � � <br /> granular material ' 42 � 6�" ; No protection required <br /> , , . <br /> .._..-�---�--•-•---._.._..-----•-•--.._.._..,_._..----•�----�--•---•-------------•-•-----�-*-----••----�------•-----._._.--••--�----••--}•-----__.._--••-�----••----------__.-_.-- <br /> Poorly-drained ' � � <br /> granular material ': 48n � �2" ; No protection required <br /> � , ; <br /> -•-•--••--�----------------------•--------•-*-------�-��----••----••----••--------•-----•-•�----•-•------•-�------•----�------•-----------�.._.._._-----------_.------•�-------�-----� <br /> Pooriy-drained • � � <br /> clayey material ; 48n � 72n ; No protection required <br /> � <br /> Note (A): Protection against frost heaving and adfreezing must be provided. <br /> FOUNDATION AND SUBGRADE PROTECTlON All built foundations subjected to freezing <br /> temperatures must be embedded according to TABLE F. This includes foundations in heated <br /> areas subjected to freezing temperatures before heating. BUILDING SUPPORT soil must be kept <br /> dry continuously and frost-free before embedment protection is provided. Accumulating or <br /> standing water must be prevented from wetting support soil before embedment protection is <br /> provided. Embedment protection must be provided to built foundations without delay. <br /> FROST HEAVE AND ADFREEZING PROTECTION All foundations subjected to freezing must be <br /> designed against detrimental effects from frost penetration. These include perimeter wall <br /> foundations in heated buildings and foundations in unheated buildings and structures. Frost <br /> penetration can cause frost heave and adfreezing. Frost penetration can occur if three conditions <br /> exist: freezing temperatures, frost-susceptible soil, and capillary water "wicking" to the bottom of <br /> the freezing zone. Frost-penetrated soil expands in volume and it can heave the ground surface <br /> upward. Adfreezing occurs when soil freeze-bonds to foundation surfaces. Frost heave induces <br /> upward acting shear strain along vertical foundation surtaces. This strain can potentially�drag <br /> foundation surfaces upward. When this upward directed shear strain is greater than downward <br /> directed building loads, upward heave of the foundation can potentially occur. If foundations are <br /> not properly designed to resist frost heave and adfreezing forces, then seasonal ground freezing <br /> can potentially create structural distress (cracking and distortion). Three methods described below <br /> should be considered in designing foundations to resist frost penetration. Altematively, a bond <br /> breaker can be used to prevent soil from adfreezing onto foundation surfaces. <br /> Allied Project 05039 13 July 31, 2005 <br />