Systems and methods for inserting support members into the ground

Abstract

Support members for heliostats (or other components installed in a field) can be hollow and thin-walled, for example, to reduce construction and/or material costs. However, such support members may be relatively fragile and susceptible to buckling or other damage when driven into relatively rocky and/or hard-packed soil using pile-driving. To avoid damaging the support members, the soil may be pre-conditioned to loosen the soil prior to insertion of the support member therein. An auger can drill a hole in the soil and then be reversed such that soil remains in and/or is subsequently re-introduced into the hole after removal of the auger, thereby leaving a substantially loosened column of soil in the hole. Vibration hammering can cause temporary liquefaction of the soil around the support member to insert the support member into the column of soil while reducing the potential for damage to the support member.

1 - 12 . (canceled) 
     
     
         13 . A method for installing a solar energy apparatus comprising:
 creating a column of loose soil in a hole by using an auger, the hole having a diameter D H , most of the soil in the hole during the creating remaining in the hole;   inserting a support member for the solar energy apparatus into the column of soil by vibration hammering; and   assembling one of a heliostat mirror assembly and a photovoltaic array assembly on the support member,   wherein the support member is a hollow pipe having a maximum outer diameter, D S , a wall thickness, t S , and a length, L S ,   the hole diameter D H  is at least three times the support member diameter D S ,
 the wall thickness t S  is less than 5% of the support member diameter D S , 
 the length L S  is at least 20 times the support member diameter D S , 
   the support member includes radially extending elements arranged so as to resist rotation of the support member about a longitudinal axis thereof once inserted into the column of soil,   the support member has a closed, tapered distal end, which is inserted into the column of loose soil, and an open end that remains above ground after said inserting,   the vibration hammering is such that the loose soil at or near the distal end of the support member undergoes liquefaction as the support member is inserted into said column, and   the vibration hammering includes applying a reciprocating force in a longitudinal direction of the support member while applying a downward crowd force to the support member.   
     
     
         14 . The method of  claim 13 , wherein the auger has a flighting that is at least twice the support member diameter. 
     
     
         15 . The method of  claim 13 , wherein at least 40% of the length L S  of the support member remains above ground after the inserting. 
     
     
         16 - 17 . (canceled) 
     
     
         18 . A method for installing a solar energy apparatus comprising:
 creating a column of loose soil in a hole by drilling using an auger, the hole having a diameter D H ; and   inserting a support member for the solar energy apparatus into the column of loose soil by vibration hammering,   wherein the support member is a hollow member having a maximum cross-sectional dimension, D S , and a wall thickness, t S ,   the hole diameter D H  is at least three times the support member cross-sectional dimension D S , and   the wall thickness t S  is less than 5% of the support member cross-sectional dimension D S .   
     
     
         19 . The method of  claim 18 , further comprising, after the inserting, assembling a heliostat mirror assembly or a photovoltaic array assembly on the support member. 
     
     
         20 . The method of  claim 18 , wherein the support member includes radially extending elements arranged so as to resist rotation of the support member about a longitudinal axis thereof once inserted into the column of soil. 
     
     
         21 . The method of  claim 18 , wherein, during the inserting, the support member is clamped so as to buttress a wall of the support member from an interior side and/or exterior side of the support member. 
     
     
         22 . The method of  claim 18 , wherein the vibration hammering is such that the loose soil at or near a distal end of the support member undergoes liquefaction as the support member is inserted into the column. 
     
     
         23 - 33 . (canceled) 
     
     
         34 . A method for installing a solar energy apparatus comprising:
 drilling a hole in soil using an auger;   reversing a direction of the auger in the hole while removing the auger so as to leave a column of loose soil in said hole; and   inserting a support member for the solar energy apparatus into the column of soil by vibration hammering,   wherein the support member is a hollow member having a maximum cross-sectional dimension, D S , and a wall thickness, t S , and   the wall thickness t S  is less than 5% of the support member cross-sectional dimension D S .   
     
     
         35 . The method of  claim 34 , wherein the auger has a flighting that is at least twice the support member diameter. 
     
     
         36 . The method of  claim 34 , wherein at least some soil is expelled from the hole during the drilling. 
     
     
         37 . The method of  claim 36 , further comprising, after the reversing and before the inserting, re-introducing the expelled soil into the hole. 
     
     
         38 . The method of  claim 34 , wherein a depth of the hole is at least 2 meters. 
     
     
         39 . The method of  claim 34 , wherein after the reversing at least some of the hole is devoid of solid material. 
     
     
         40 . The method of  claim 34 , wherein at least 10% of the volume of the hole is devoid of solid material. 
     
     
         41 . The method of  claim 34 , wherein the hole diameter D H  is at least three times the support member diameter D S . 
     
     
         42 . The method of  claim 34 , further comprising, after the inserting, assembling a heliostat mirror assembly or a photovoltaic array assembly on the support member. 
     
     
         43 . The method of  claim 34 , wherein, during the inserting, the support member is clamped so as to buttress a wall of the support member from an interior side and/or exterior side of the support member. 
     
     
         44 . The method of  claim 34 , wherein the vibration hammering is such that the loose soil at or near a distal end of the support member undergoes liquefaction as the support member is inserted into the column. 
     
     
         45 . The method of  claim 34 , wherein the vibration hammering includes applying a reciprocating force in a longitudinal direction of the support member while applying a downward crowd force to the support member via a surrogate object in contact with an interior surface or an exterior surface of the support member. 
     
     
         46 - 63 . (canceled)