Post tensioned foundations, apparatus and associated methods

Abstract

Described herein are shallow post tensioned foundation systems for mounting light to medium weight structures. Methods of installation are also described. The systems, apparatus and methods described can reduce waste, increase efficiency and reduce cost and installation/construction time.

I claim: 
     
         1 . A method of installing a post tensioned foundation comprising the steps:
 a. filling a feed cavity associated with a post tensioned foundation installation device driven and rotated to a depth with at least one type of aggregate;   b. leaving a bottom reaction plate attached to a tensioning rod at the depth;   c. moving the post tensioned foundation installation device upward to a predetermined height thereby creating a void and releasing the at least one type of aggregate into the void while rotating the post tensioned foundation installation device until a specified amount of aggregate is deposited around a perimeter of a mandrel;   d. compacting the at least one type of aggregate within the void thereby creating compacted aggregate;   e. securing a top reaction plate to the tensioning rod over the compacted aggregate; and   f. installing the post tensioned foundation.   
     
     
         2 . The method according to  claim 1 , wherein the post tensioned foundation installation device is rotated. 
     
     
         3 . The method according to  claim 1 , wherein steps c-d are repeated until a desired amount of compacted aggregate has been processed. 
     
     
         4 . The method according to  claim 1 , wherein the post tensioned foundation installation device comprises
 a first end and a second end, the first end having a compaction element and the second end having a power tool attachment section;   a transversal rod guide conduit originating at the compaction element and terminating at or before the power tool attachment section; and   an outer skin defining an aggregate feed cavity, wherein the outer skin includes at least one aggregate port.   
     
     
         5 . The method according to  claim 4 , wherein a tension rod is housed within the transversal rod guide and a bottom reaction plate rests against the compaction element. 
     
     
         6 . The method according to  claim 1 , further comprising filling the remaining void with at least one type of soil and compacting the at least one type of soil before step e. 
     
     
         7 . The method according to  claim 1 , wherein steps c and d are preformed simultaneously. 
     
     
         8 . The method according to  claim 1 , wherein the top reactionplate is precast concrete, steel, GFRP, plastic, nylon, HDPE, recycled materials, or a combination thereof. 
     
     
         9 . A post tensioned foundation installation system comprising
 a mandrel including a first end and a second end, the first end including a compaction element and the second end including a power tool attachment section;   a transversal rod guide conduit originating at the compaction element and terminating at or before the power tool attachment section; and   an outer skin defining an aggregate feed cavity, wherein the outer skin includes at least one aggregate port.   
     
     
         10 . The post tensioned foundation installation system according to  claim 9 , wherein the aggregate feed cavity includes at least one horizontal compaction element. 
     
     
         11 . The post tensioned foundation installation system according to  claim 9 , further comprising a tension rod assembly having a tensioning rod and at least one reaction plate. 
     
     
         12 . The post tensioned foundation installation system according to  claim 11 , wherein the tensioning rod is housed within the transversal rod guide and a bottom reaction plate rests against the compaction element. 
     
     
         13 . The post tensioned foundation installation system according to  claim 12 , wherein the reaction plates are flat. 
     
     
         14 . The post tensioned foundation installation system according to  claim 12 , wherein at least one of the reaction plates is conical. 
     
     
         15 . The post tensioned foundation installation system according to  claim 14 , wherein a bottom reaction plate is threaded. 
     
     
         16 . The post tensioned foundation installation system according to  claim 11 , wherein the tensioning rod is threaded. 
     
     
         17 . The post tensioned foundation installation system according to  claim 11 , wherein the compaction element includes at least one first torque transfer element. 
     
     
         18 . The post tensioned foundation installation system according to  claim 17 , wherein at least one of the reaction plates includes a second torque transfer element that weds with the at least one first torque transfer element. 
     
     
         19 . A post tensioned foundation installation system comprising
 a mandrel including an outer skin having a first end and second end, the first end including a first portion to attach a compaction element and the second end including a second portion to attach a drive adapter;   a transversal rod guide originating at the first end, extending through the mandrel, and held in place by at least one transversal rod guide support;   at least one interior compaction element attached to the transversal rod guide and the outer skin to assist in compacting aggregate against the side wall of a column associated with at least one side aggregate port in the outer skin; and   a tensioning rod and at least one reaction plate.   
     
     
         20 . The post tensioned foundation installation system according to  claim 19 , wherein the at least one interior compaction element is curved downward in a spiral. 
     
     
         21 . The post tensioned foundation installation system according to  claim 19 , wherein the tensioning rod is threaded.