CPT معادل SPT و يا SPT تعيين ظرفيت باربري پي هاي عميق با استفادهاز نتايج

Determining Ultimate Capacity of Deep Foundations Using SPT and/or SPT- CPT Equivalent Results

Application of in-situ testings such as SPT and CPT is a common practice for determining vertical ultimate capacity of deep foundations as supplement of static analysis. Based on N value from SPT and/or N -- qe equivalent from CPT a proposed method is presented and compared with current methods. In addition to simplification, data processing failure zone extension and limit load of piles has been emphasized in proposed approach. Fifty three case histories have been collected including full scale pile load tests in which SPT and/or CPT were performed close to pile locations. Using 19 cases the interpretation methods of P - It results from pile load tests, have been verified to evaluate plunging criteria. Comparison of errors for pile capacity prediction has been done with graphical, numerical and cumulative probability approaches. The results demonstrates less error and more accuracy for proposed method than others for pile capacity estimation. Moreover, all of six methods predict pile capacity with more precision using SPT-CPT equivalent data than only when SPT data used .