SHEER FAILURE IN A STRIP FOUNDATION

-IF THE THICKNESS OF A CONCRETE STRIP FOUNDATION (WITHOUT STEEL REINFORCEMENT ) WERE LESS THAN ITS PROJECTION EACH SIDE OF A WALL , THE CONCRETE MIGHT FAIL THROUGH THE WEIGHT OF THE WALL CAUSING A 45 DEGREE ANGLE SHEAR CRACK.
-IF THIS OCCURRED , THE BEARING SURFACE OF THE FOUNDATION ON THE GROUND WOULD BE REDUCED TO LESS THAN THAT NECESSARY FOR STABILITY .
-WHERE THE LOAD IS PLACE DIRECTLY ON TOP OF THE CONCRETE FOUNDATION AND COMPRESSED BETWEEN THE GROUND , THE FOUNDATION REMAINS STABLE . HOWEVER , THE CONCRETE OUTSIDE THE 45 DEGREE ANGLE EXPERIENCE SOME TENSION AS THE REACTION OF THE GROUND ATTEMPS TO LEVER THE FOUNDATIONS UPWARDS , THUS THE FOUNDATION WOULD FAIL .

IF THE LENGTH OF THE SIDE OF STRIP FOUNDATION IS GREATER THAN THE DEPTH OF THE REINFORCEMENT CONCRETE , THE FOUNDATION WILL BE FAIL WHERE TENSION IS EXERTED ON THE CONCRETE WILL CAUSE THE 45' DEGREE OF SHEAR , FOLLOWING THE SHEAR FAILURE , THE LOAD IS CONCRENTRATED ON A SMALLER AREA , THE GROUND MAY CONSOLIDATE UNDER THE INCREASED LOAD