PILE WALLS ARE AMONG POPULAR METHODS FOR CONSTRUCTING BERTHS, AND IN PLACES WHERE THE SEABED IS HARD AND DENSE, THE ERECTION OF STANDARD PILES BECOMES DIFFICULT, ESPECIALLY IF THE FREE HEIGHT OF BERTH IS SIGNIFICANT AND, CONTROLLING THE PILE DURING ERECTION AND SUPPORT GETS COMPLICATED. HOWEVER, STANDARD PILES ARE NOT ALWAYS AVAILABLE IN IRAN AND AN ALTERNATIVE WOULD BE ERECTING PIPE TRESSES PARALLEL TO EACH OTHER IN ORDER TO MAKE A CONTIGUOUS PIPE PILE WALL. ANALYZING THESE STRUCTURES BY ORDINARY METHODS DOES NOT USUALLY CONSIDER THEIR LIMIT BALANCE, CONTROL FORCE DURING CONSTRUCTION AND OPERATION, AND THEIR BEHAVIOR THROUGH EARTHQUAKES WITH THE DESIRED PRECISION. IN BERTHS WITH A SIGNIFICANT FREE HEIGHT, CONSTRUCTION IS CONDUCTED HIGHER THAN THE NORMAL SCALE IN DIFFERENT STAGES, AND CAN LEAD TO DISLOCATION OR OTHER SIMILAR PROBLEMS. IN SUCH CASES, USING NUMERICAL ANALYSIS METHODS, SUCH AS LIMITED ELEMENTS THAT CAN PROPERLY MODEL THE CONSTRUCTION PROCESS, COULD PROVE OPTIMAL IN DESIGNING CONTIGUOUS PIPE PILE WALLS. IN THIS PAPER, THE PLAXIS SOFTWARE PACKAGE USING THE LIMITED ELEMENTS MODEL WAS ANALYZED IN DESIGNING A CONTIGUOUS PIPE PILE WALL IN THE SERVICE PORT OF PARS IN ASSALUYEH, AND ITS PERFORMANCE IN DIFFERENT CONDITIONS WAS CONSIDERED.

PILES ARE NORMALLY CONSTRUCTED IN GROUPS AND CLOSE TO EACH OTHER. THIS CAUSES THAT PILES INTERACT. THIS PAPER DEVELOPS A NEW APPROACH FOR DETERMINATION OF INTERACTION FACTOR BETWEEN CLOSELY SPACED PILES IN THE GROUP. THE SEGMENT BY SEGMENT METHOD (SSM) INITIALLY DEVELOPED BY THE FIRST AUTHOR IS USED TO DETERMINE LOAD-CARRYING CHARACTERISTICS OF BOTH THE “SOURCE” (LOADED) AND THE “RECEIVER” (LOAD-FREE) PILES. THE MAIN SUPERIORITY OF THE NEW APPROACH PRESENTED IN THIS PAPER IS THAT THE PRESENCE OF THE “RECEIVER” PILE IS TAKEN INTO ACCOUNT, UNLIKE OTHER AVAILABLE METHODS. MOREOVER, THE SSM FACILITATES TO DEAL WITH THE SOIL INHOMOGENEITY IN THE VERTICAL DIRECTION. IN THE SSM, IT IS ASSUMED THAT THE SOIL AND THE PILE HAVE LINEAR ELASTIC BEHAVIOR AND NO SLIP OCCURS BETWEEN THE SOIL AND THE PILE. THE DEVELOPED METHOD CALCULATES THE STATIC VERTICAL INTERACTION FACTOR FOR LAYERED SOILS CONSIDERING THE FLEXIBILITY OF THE “RECEIVER” PILE. THE DEVELOPED METHOD CLARIFIES THE SHORTCOMING OF EXISTING METHODS THAT BASICALLY IGNORES THE PRESENCE OF THE “RECEIVER” PILE. PARAMETRIC STUDIES HAVE BEEN PERFORMED, SHOWING THE CAPABILITY OF THE METHOD BASED ON ITS SIMPLICITY AND ALSO EFFICIENCY IN CALCULATING THE STATIC VERTICAL INTERACTION FACTORS IN INHOMOGENOUS SOILS WITHOUT LIMITATION IN NUMBER OF SOIL LAYERS.

IN THIS PAPER THE BEARING CAPACITY OF CYLINDRICAL, TAPERED AND STEPPED PILES UNDER VERTICAL STATIC LOADS HAS BEEN INVESTIGATED USING FINITE DIFFERENCE METHOD BASED ON THE COMMERCIALLY AVAILABLE CODE, FLAC 3D (FAST LAGRANGIAN ANALYSIS OF CONTINUA). THE PILE IS ASSUMED TO HAVE LINEARLY ELASTIC. THE MAIN OBJECTIVE OF THE PAPER IS TO INVESTIGATE WHETHER A TAPERED PILE CAN BE IDEALIZED AS SOME PRISMATIC SEGMENTS CONNECTED RIGIDLY AT NODES. THE SOIL FAILURE IS ASSUMED TO OBEY MOHR-COULOMB CRITERION. THE SOIL-PILE INTERACTION HAS BEEN MODELED USING INTERFACE ELEMENTS. SUCH ELEMENTS ALLOW THE PILE TO SLIP FROM THE SOIL WHEN NECESSARY. A CYLINDRICAL PILE OF THE SAME VOLUME AND LENGTH HAS ALSO BEEN ANALYZED. THIS FACILITATES TO COMPARE LOAD-CARRYING CAPACITY OF PRISMATIC, UNIFORMLY TAPERED, AND STEP-TAPERED PILES OF THE SAME VOLUME AND LENGTH. TO ENSURE THE ACCURACY OF THE CONSTRUCTED NUMERICAL MODEL OF PILES, THE RESULTS OBTAINED FROM NUMERICAL ANALYSIS HAVE BEEN COMPARED WITH THOSE OBTAINED FROM EXPERIMENTAL AND THEORETICAL APPROACHES. THIS COMPARISON INDICATES A VERY GOOD AGREEMENT. IT WILL BE SHOWN THAT A UNIFORMLY TAPERED PILE CANE BE CONFIDENTLY IDEALIZED AS A NUMBER OF PRISMATIC SEGMENTS WHICH ARE CONNECTED TO EACH OTHER. THIS IS AN INTERESTING FINDING AND ENABLES USERS TO APPLY SIMPLE ONE DIMENSIONAL NUMERICAL ANALYSIS FOR DETERMINATION OF PILE CAPACITY.