UFC 3-220-07

Abstract

a. Guidelines of the geotechnical investigation and analysis necessary for selection and design of militarytype buildings constructed in expansive clay soil areas, as outlined in chapters 2 to 5, consist of methods for the recognition of the relative magnitude of the swelling soil problem at the construction site, field exploration, laboratory investigations, and application of methodology for prediction of volume changes in swelling foundation soils. Chapter 6 presents guidance for selection of the type of foundation with structural details of design procedures provided for reference. Chapters 7 to 9 discuss methods of minimizing foundation movement, construction techniques and inspection, and considerations for remedial repair of damaged structures.<br>b. Guidance is not specifically provided for design of highways, canal or reservoir linings, retaining walls, and hydraulic structures. However, much of the basic information presented is broadly applicable to the investigation and analysis of volume changes in soils supporting these structures and methods for minimizing potential soil volume changes. Guidance is also not specifically provided for the design of structures in areas susceptible to soil volume changes from frost heave and chemical reactions in the soil (e.g., oxidation of iron pyrite), although much of the information presented can be useful toward these designs.<br><strong>Purpose</strong><br>This manual presents guidance and information for the geotechnical investigation necessary for the selection and design of foundations for heavy and light military-type buildings constructed in expansive clay soil areas. The information in this manual is generally applicable to many types of structures such as residences, warehouses, and multistory buildings. Emphasis is given to the maintenance of an environment that encourages constant moisture conditions in the foundation soils during and following construction. Special attention must always be given to specific requirements of the structure such as limitations on allowable differential movement. <br>a. The guidance and information provided in this manual can significantly reduce the risk of undesirable and severe damages to many structures for numerous expansive soil conditions. However, complete solutions for some expansive soil problems are not yet available; e.g., the depth and amount of future soil moisture - changes may be difficult to predict. <br>b. This manual presents guidance for selecting economical foundations on expansive soil to minimize structural distress to within tolerable levels and guidance for minimizing problems that may occur in structures on expansive soils.