Controlled system for the densification of weak soils

Abstract

A method of imparting strength to earth in support of a ground surface is disclosed. A bag is placed in the earth under the ground surface, the bag having a first end oriented towards the ground surface, a second end opposite the first end, and a cross sectional contour from the first end to the second end that includes at least one wedge portion extendable laterally into surrounding earth located above and below the wedge portion when the bag is filled. A expandable polymeric resin is injected into the bag to at least partially fill the bag to compress earth around the bag. The expandable polymeric resin may be expandable polymeric resin. A bag is also disclosed for use in imparting strength to earth in support of a ground surface. The bag comprises at least an opening, a first end and a second end opposed the first end, and a cross sectional contour from the first end to the second end that includes at least one wedge portion extendable laterally into surrounding earth above and below the wedge portion when the bag is filled and in earth under the ground surface

1 . A method of imparting strength to earth in support of a ground surface comprising:
 placing a bag in the earth under the ground surface, the bag having a first end oriented towards the ground surface, a second end opposite the first end, and a cross sectional contour from the first end to the second end that includes at least one wedge portion extendable laterally into surrounding earth located above and below the wedge portion when the bag is filled; and   injecting expandable polymeric resin into the bag to at least partially fill the bag to compress earth around the bag.   
     
     
         2 . The method of  claim 1  in which the wedge portion is defined annularly around an axis of the bag. 
     
     
         3 . The method of  claim 1  in which the bag has at least two wedge portions. 
     
     
         4 . The method of  claim 1  in which the bag has an hourglass cross sectional contour from the first end to the second end. 
     
     
         5 . The method of  claim 1  in which the wedge portion is oriented in a first strata of earth over a second strata, the first strata of earth being weaker than the second strata. 
     
     
         6 . The method of  claim 1  in which the wedge portion comprises a sloped ledge. 
     
     
         7 . The method of  claim 1  in which the wedge portion comprises an arm. 
     
     
         8 . The method of  claim 1  in which the expandable polymeric resin is injected through a valved opening in the bag. 
     
     
         9 . The method of  claim 8  in which placing the bag in the earth under the ground surface further comprises placing the bag in the earth with an injector inserted through the opening of the bag, and in which expandable polymeric resin is injected into the bag from an injection end of the injector. 
     
     
         10 . The method of  claim 9  further comprising removing the injection end from the bag. 
     
     
         11 . The method of  claim 1  in which expandable polymeric resin is injected into the bag in a pre-determined amount selected to rupture the bag. 
     
     
         12 . A bag for use in imparting strength to earth in support of a ground surface comprising:
 at least an opening;   a first end and a second end opposed the first end; and   a cross sectional contour from the first end to the second end that includes at least one wedge portion extendable laterally into surrounding earth above and below the wedge portion when the bag is filled and in earth under the ground surface.   
     
     
         13 . The bag of  claim 12  in which the opening further comprises a backflow prevention valve to prevent material contained within the bag from passing out of the bag when the opening is unobstructed. 
     
     
         14 . The bag of  claim 12  in which a portion of the cross sectional contour is tapered conically outwards from the base. 
     
     
         15 . A structural support for a ground surface comprising the bag of  claim 12  located in earth under the ground surface and at least partially filled with expandable polymeric resin to compress the earth around the bag. 
     
     
         16 - 33 . (canceled) 
     
     
         34 . A method of imparting strength to weak soils in support of a ground surface, the method comprising:
 carrying out a geotechnical survey on the weak soils to determine a soil weakness profile;   placing a bag or stack of bags in the weak soils, the bag or stack of bags being selected to have a shape that conforms to the soil weakness profile such that a portion of the bag or stack of bags placed in a weaker layer of the weak soils has a greater diameter than another portion of the bag or stack of bags placed in a stronger layer of the weak soils; and   injecting expanding polymeric resin into the bag or stack of bags to compress the weak soils around the bag or stack of bags.   
     
     
         35 . The method of  claim 34  in which the portion placed in the weaker layer comprises at least one bag. 
     
     
         36 . The method of  claim 34  in which the portion placed in the weaker layer comprises part of a bag, and the another portion placed in the stronger layer comprises another part of the bag. 
     
     
         37 . The method of  claim 34  in which the portion placed in the weaker layer forms a supportive bridge between stronger layers of soil. 
     
     
         38 . The method of  claim 1  in which the earth comprises at least one of weak alluvial soils, silts, clay, peat, hog fuel, wood chips, and water saturated soils. 
     
     
         39 . The method of  claim 1  in which the earth supports a railroad track on the ground surface. 
     
     
         40 - 41 . (canceled)