Foundation at Different Levels

In that case footings on granular soil, the distance among the footings should be such that a line drawn among the lower adjacent edges of the footings shall not have a slope steeper than one vertical to two horizontal as display in Figure 2.

                                         Figure 2: Footings on Granular Soil

In clayey soils, a line drawn among the lower adjacent edge of the upper footing and the upper adjacent edge of the lower footing should not have a slope steeper than one vertical to two horizontal as display in Figure 3.

                                 Figure 3: Footings on Clayey Soil