Failure of Boundary Walls in Bhopal: An Investigation

In Bhopal, the widespread occurrences of cracking due to alternate swelling and shrinking in lightly loaded structures provided with traditional foundation like the strip footings in are covered by swelling soil. It is likely that foundation movements, due to shrinkage and swelling of expansive soil as a result of moisture content changes are responsible for more damage to building than any other single cause. This forced the Builders and Engineers to take notice and adopt suitable measures to overcome this problem. It relates to light loaded structure that is may not be possible to develop large enough downwards loads to exert the required pressure beneath the supports of the smallest practicable size. Further more, swelling can be prevented only in a localized zone beneath the footing (lying within the bulb of pressure of intensity equal to swelling pressure), where the stresses induced by the foundation are concentrated. The soil beyond the pressure bulb would still swell, and so will the soil in areas between the adjacent footings. The boundary walls are an important part of the building which stride boundary line and used to separate the properties, but it is not a part o9f building because building has a roof, floor, doors and windows while boundary wall has no such type of arrangement. KEYWORD : Swelling, shrinkage, settlement, design and quality in black cotton soil.