ULTIMATE BEARING CAPACITY OF SHALLOW STRIP FOUNDATIONS UNDER SUITABLE LOADING - THEORY AND TEST

DIE GRENZTRAGFAEHIGKEIT VON FLACH GEGRUENDETEN STREIFENFUNDAMENTEN UNTER GEEIGNETER BELASTUNG NACH THEORIE UND VERSUCH

USING THE SMOLTCZYK (1960) CALCULATION METHOD FOR LAMBDA (B) (RHO, DELTA) AND LAMBDA (T) (RHO, DELTA), THEORECTICAL SLOPE FACTORS KAPPA (B) (DELTA) AND KAPPA (T) DELTA WERE RE-CALCULATED FOR THE WIDTH TERM AND DEPTH TERM OF THE HYDRAULIC FAILURE EQUATION FOR INCLINED LOADING ANGLES 0 < = DELTA < = 45 DEGREES AND ANGLE OF FRICTION 30 DEGREES < = RHO < = 45 DEGREES. FOR THE EXPERIMENTAL DETERMINATION OF THE SLOPE FACTORS, NINE LOADING TESTS WERE CARRIED OUT IN AN UNEVEN GRAVELLY SAND WITH A FOUNDATION OF 1.0 X 3.0 M WITH AND WITHOUT ANCHORING DEPTH. THE ANGLE OF LOADING DELTA THUS VARIED BETWEEN LIMITS OF 0 AND 30 DEGREES; THE LOAD ACTED ACROSS THE DIRECTION OF THE FOUNDATION WHICH CORRESPONDS APPROXIMATELY TO THE THEORETICAL SOLUTION APPLICABLE FOR THE HORIZONTAL CASE. FROM THE TEST RESULTS, THE EFFECT OF INCLINED LOADING ON THE LIMITING LOADING CAPACITY FOR SLOPES DELTA = 20 DEGREES WAS OBTAINED SUFFICIENTLY ACCURATELY FROM THE SLOPE FACTORS KAPPA (B) (DELTA) = (1-TAN DELTA) 2 AND KAPPA (T) (DELTA) = (1-TAN DELTA). CONPARISON OF THE THEORETICAL AND EXPERIMENTAL SLOPE FACTORS SHOWS THAT THE RELATION DETERMINED EXPERIMENTALLY IS LESS MARKED. SLIDING, IN THE REAL SENSE, WAS NOT OBSERVED IN ANY OF THE TESTS. THE RESISTANCE TO SLIDING WAS THUS ALWAYS GREATER THAN 1. THE TEST RESULTS HAVE THEREFORE CLEARLY SHOWN THAT THE CONCEPT ON WHICH THE OLDER METHOD OF CALCULATION WAS BASED IS NOT CORRECT.