Assignment

Assignment

Assignment

Task 1:

It would seem very easy to ignore the drab aspect of that portion of the library structure which is subsequently hidden from public view. Unfortunately, very serious and costly consequences can develop if inadequate treatment is given to the substructure which is to support the finished building, together with its intended contents and activities. Attention may be focused upon only three aspects--the soil bearing properties, the frost line, and waterproofing. With rare exceptions, reinforced concrete of the proper quality and composition is the material used for footings, foundation walls, and column piers (Chew 1999).

The bearing properties of the soil and its substrata are related to the matter of site selection. As a general rule, a relatively high site with only a moderate slope is to be preferred. It is noted that a number of quite sizable library buildings, both academic and public, have recently been constructed on sites where the slope is such that grade, or ground level, entry can be provided to at least two levels within the building. If the building is to be more than one floor in height, and unless there is reliable existing evidence, action should be taken immediately following the site selection to ascertain the nature of the strata upon which the footings and column piers are to rest. It is preferable for all footings and piers to be placed upon the same, or upon equally stable, strata. The bearing capacity of the soil is vital in considering provisions for future expansion of the facility either horizontally or vertically (Phillips 2002).

The "frost-line" consideration is of primary concern in one-floor buildings. In multi-floored structures, the soil bearing aspect, or the choice of a subgrade floor level, usually obviates this problem. However, with the advent of forced circulation heating and the use of fuel oil or natural gas in lieu of coal, it is practicable to construct--especially the smaller, eg, branch--libraries of one floor, placed at or near the grade level. Footings for foundations should be placed at a depth in excess of the nominal frost-line because frost damage to footings is more severe where the soil has higher moisture content. Any portion of a structure below grade is subject to possible water difficulties. The provisioning of proper and adequate drainage at the level of the footing will materially reduce the severity of the problem. Whereas good concrete is impermeable to water, the fact that the footings, foundation walls, piers, and basement floor are not all poured at the same time--hence not monolithic--permits for joints through which seepage can occur. Of the two types of waterproofing used to overcome this situation, the more effective is the "membrane" type which consists in constructing what is essentially a waterproof box, integral with the floor and the walls (Doms 2002).

Several layers of a crude cloth felt are placed on the subfloor and are mopped with hot asphalt. The finish floor concrete slab is poured over this barrier. Using the same materials, the foundation wall is ...