Pre-Stressed Modular Retaining Wall System and Method

Abstract

The present invention relates to a system and method for constructing a pre-stressed modular construction for supporting or retaining an applied load. In particular, the present invention relates to a system and method for pre-stressed modular retaining walls. The system comprises a plurality of header stacks constructed from a variety of header units. The header stacks are coupled by structural members. Active reinforcement elements are used to induce a pre-stressing force into the header stacks to support or retain the applied load. A method for constructing the modular construction is provided.

1 .- 73 . (canceled) 
   
   
       74 . An apparatus, comprising:
 a header configured to be stacked with an adjacent header to form a load-bearing structure, the header including an upper surface, a lower surface, and a side surface,   the upper surface of the header configured to be in contact with a lower surface of the adjacent header, the upper surface of the header defining an opening configured to receive a protrusion of the lower surface of the adjacent header when the header is stacked with the adjacent header such that the side surface of the header and a side surface of the adjacent header form a substantially continuous surface,   the header defining a lumen therethrough configured to receive an active reinforcement element, the active reinforcement element configured to impart a pre-stressing force associated with the header.   
   
   
       75 . The apparatus of  claim 74 , wherein:
 the upper surface of the header is substantially planar; and   the lower surface of the header is substantially planar and parallel to the upper surface of the header.   
   
   
       76 . The apparatus of  claim 74 , wherein:
 the opening is a first opening; and   the upper surface of the header defines a second opening, the second opening in communication with the lumen, the second opening configured to receive a lock-off element.   
   
   
       77 . The apparatus of  claim 74 , wherein:
 the opening is a first opening; and   the upper surface of the header defines a second opening, the second opening in communication with the lumen, the second opening having a non-circular shape, the second opening configured to receive a lock-off element such that a surface of the lock-off element is flush with the upper surface of the header.   
   
   
       78 . The apparatus of  claim 74 , wherein the header is configured to be coupled to a secondary structural member such that the header, the adjacent header, and the secondary structural member collectively form at least a portion of a retaining wall. 
   
   
       79 . The apparatus of  claim 74 , wherein:
 the lumen is a first lumen, a longitudinal axis of the first lumen being substantially normal to the upper surface of the header; and   the header defines a second lumen configured to receive a passive reinforcement element, a longitudinal axis of the second lumen being substantially parallel to the upper surface of the header.   
   
   
       80 . The apparatus of  claim 74 , wherein the side surface of the header and the side surface of the adjacent header form a substantially coplanar surface when the header is stacked with the adjacent header and when the opening of the first surface of the header receives the protrusion of the lower surface of the adjacent header. 
   
   
       81 . The apparatus of  claim 74 , wherein:
 the adjacent header is a first adjacent header; and   the lower surface of the header includes a protrusion configured to be disposed within an opening of an upper surface of a second adjacent header.   
   
   
       82 . The apparatus of  claim 74 , further comprising the active reinforcement element. 
   
   
       83 . The apparatus of  claim 74 , further comprising the active reinforcement element, the active reinforcement element being bonded within the lumen. 
   
   
       84 . An apparatus, comprising:
 a header configured to be stacked with an adjacent header to form a load-bearing structure, the header including a first end portion, a second end portion, and a central portion disposed between the first end portion and the second end portion,   an upper surface of the central portion including a corrugated portion configured to matingly fit with a corrugated portion of a lower surface of the adjacent header when the header is stacked with the adjacent header such that a side surface of the central portion of the header and a side surface of the adjacent header are substantially aligned,   the first end portion of the header defining a lumen therethrough configured to receive a reinforcement element.   
   
   
       85 . The apparatus of  claim 84 , wherein:
 the lumen of the first end portion is configured to receive an active reinforcement element configured to impart a pre-stressing force associated with the header.   
   
   
       86 . The apparatus of  claim 84 , wherein:
 the opening is a first opening;   the lumen of the first end portion is configured to receive an active reinforcement element configured to impart a pre-stressing force associated with the header; and   a surface of the first end portion of the header defines a second opening, the second opening in communication with the lumen, the second opening configured to receive a lock-off element, the lock-off element configured to engage the active reinforcement element to maintain a post-tensioning force applied to the active reinforcement element.   
   
   
       87 . The apparatus of  claim 84 , wherein the lumen of the first end portion includes a conduit therein, the conduit configured to prevent the reinforcement element from being bonded directly to the header within the lumen. 
   
   
       88 . The apparatus of  claim 84 , wherein:
 a width of the first end portion of the header is substantially equal to a width of the second end portion of the header; and   a width of the central portion of the header is less than the width of the first end portion of the header.   
   
   
       89 . The apparatus of  claim 84 , wherein the header is configured to be coupled to a secondary structural member such that the header, the adjacent header, and the secondary structural member collectively form at least a portion of a retaining wall. 
   
   
       90 . The apparatus of  claim 84 , wherein the side surface of the central portion of the header and the side surface of the adjacent header form a substantially coplanar surface when the header is stacked with the adjacent header and when the corrugated portion of the upper surface of the central portion is matingly fit with the corrugated portion of the lower surface of the adjacent header. 
   
   
       91 . An apparatus, comprising:
 a header configured to be stacked with an adjacent header to form a load-bearing structure, the header including a first end portion, a second end portion, and a central portion disposed between the first end portion and the second end portion,   a width of the first end portion of the header being substantially equal to a width of the second end portion of the header, a width of the central portion of the header being less than the width of the first end portion of the header,   the header defining a lumen therethrough configured to receive an active reinforcement element, the active reinforcement element configured to impart a pre-stressing force associated with the header.   
   
   
       92 . The apparatus of  claim 91 , wherein:
 an upper surface of the central portion defines an opening configured to receive a protrusion of the lower surface of a central portion of the adjacent header when the header is stacked with the adjacent header.   
   
   
       93 . The apparatus of  claim 91 , wherein:
 a height of the first end portion of the header is substantially equal to a height of the second end portion of the header; and   the height of the first end portion of the header is substantially equal to a height of the central portion of the header.   
   
   
       94 . The apparatus of  claim 91 , wherein:
 the opening is a first opening; and   a surface of the first end portion of the header defines a second opening, the second opening in communication with the lumen, the second opening configured to receive a lock-off element, the lock-off element configured to engage the active reinforcement element to maintain a post-tensioning force applied to the active reinforcement element.