Abstract:
The embodiments provided herein are directed to a telescopic foundation screw piles with continuously tapered pile body that facilitates a faster pile placement speed, less labor and operators, less material, single step operation, low overhead clearance, no excess soils to be removed and hauled away which translates in lower cost and greater ease of use as well as higher load capacity.

Description:
FIELD 
       [0001]    The embodiments described herein generally relate to a foundation pile, in particular, to a telescopic foundation screw pile with continuously tapered pile body. 
       BACKGROUND OF THE INVENTION 
       [0002]    Foundation piles are widely used (e.g., in the building or other structural fields) for anchoring a component to the ground. Typically, a foundation pile has a retaining portion in the upper region for receiving the anchored component. 
         [0003]    A conventional drilled pile can be installed by first drilling a borehole into the ground. Then, a temporary casing is used to seal the borehole through water-bearing or unstable strata overlying suitable stable material. Upon reaching a desired depth, a reinforcing cage is introduced. Then, concrete is poured into the borehole and brought up to the required level. One disadvantage of the conventional drilled pile is that it is labor and material intensive. 
         [0004]    An auger-cast pile, often known as a CFA pile, can be formed by drilling into the ground with a hollow stemmed continuous flight auger to a desired depth or degree of resistance. A cement grout mix is then pumped down the stem of the auger. While the cement grout is pumped, the auger is slowly withdrawn, conveying the soil upward along the flights. A shaft of fluid cement grout is formed to ground level. The Auger-cast pile causes minimal disturbance, and is often used for noise and environmentally sensitive sites. However, both the conventional drilled pile and the auger-cast pile are labor intensive, material intensive, unfit for tight spaces, unable to be placed where surcharge loads are present, high overhead clearance and depending on the situation the drilled holes could cave in and create safety concerns. For example, soils removed from the borehole need to be hauled away. In addition, where the ground in a job site is deemed to be contaminated, any soil removed from the ground must be disposed properly, which presenting an additional problem and associated cost. 
         [0005]    A more complex system (e.g., STELCOR pile made by the IDEAL Group, 999 Picture Parkway, Webster, N.Y. 14580) whereby a pile is attached to a drill head which is substantially larger than the diameter of the pile itself. The pile is turned together with the drill head by a drilling rig to create a passage in the soil bed through which the pile may pass. A conduit is provided through the center of the pile for water or grout to be pumped down and out the tip of the drill head to either float away debris or anchor the pile in its final resting place in the soil bed. Therefore, no soil is removed during pile installation. Although the system has certain advantages over other known systems, the drilling system is obviously substantially more complex, and therefore more costly than the conventional drilled pile and the auger-cast pile discussed earlier. 
         [0006]    Therefore, an improved foundation pile that facilitates a faster pile placement speed, lower cost and greater ease of use as well as higher load capacity is desirable. 
       BRIEF SUMMARY OF THE EMBODIMENTS 
       [0007]    The embodiments provided herein are directed to a telescopic foundation screw piles with continuously tapered pile body that facilitates a faster pile placement speed, less labor and operators, less material, single step operation, low overhead clearance, no excess soils to be removed and hauled away which translates in lower cost and greater ease of use as well as higher load capacity. 
         [0008]    Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. It is also intended that the invention is not limited to the details of the example embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The details of the invention, both as to its structure and operation, may be gleaned in part by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely. 
           [0010]      FIG. 1  is a schematic illustration showing an exploded view of an exemplary telescopic foundation screw pile. 
           [0011]      FIG. 2  is a schematic illustration showing an enlarged view of a portion near the meeting place between the first section and the second section of the exemplary telescopic foundation screw pile of  FIG. 1 . 
           [0012]      FIG. 3  is a schematic illustration showing a side view of the exemplary telescopic foundation screw pile of  FIG. 1 . 
           [0013]      FIG. 4  is a schematic illustration showing a cross-sectional view taken along A-A of the exemplary telescopic foundation screw pile of  FIG. 3 . 
           [0014]      FIG. 5  is a schematic illustration showing an enlarged view of a portion near the meeting place between the first section and the second section of the exemplary telescopic foundation screw pile of  FIG. 4 . 
           [0015]      FIG. 6  is a schematic illustration showing an enlarged view of a first section of the exemplary telescopic foundation screw pile of  FIG. 3 . 
           [0016]      FIG. 7  is a schematic illustration showing an enlarged view of a second section of the exemplary telescopic foundation screw pile of  FIG. 3 . 
           [0017]      FIG. 8  is a schematic illustration showing an elevation view of another exemplary telescopic foundation screw pile. 
           [0018]      FIG. 9  is a schematic illustration showing a front view of the exemplary telescopic foundation screw pile of  FIG. 8 . 
           [0019]      FIG. 10  is a schematic illustration showing a front view of a first section of the exemplary telescopic foundation screw pile of  FIG. 8 . 
           [0020]      FIG. 11  is a schematic illustration showing a cross-sectional view taken along B-B of the exemplary telescopic foundation screw pile of  FIG. 10 . 
           [0021]      FIG. 12  is a schematic illustration showing a front view of a second section of the exemplary telescopic foundation screw pile of  FIG. 8 . 
           [0022]      FIG. 13  is a schematic illustration showing an enlarged view of a portion near the lower end of the second section of  FIG. 12 . 
           [0023]      FIG. 14  is a schematic illustration showing an enlarged view of a portion near the upper end of the second section of  FIG. 12 . 
           [0024]      FIG. 15  is a schematic illustration showing a cross-sectional view taken along C-C of the exemplary telescopic foundation screw pile of  FIG. 12 . 
           [0025]      FIG. 16  is a schematic illustration showing a front view of a first section of another exemplary telescopic foundation screw pile with a plate connection. 
           [0026]      FIG. 17  is a schematic illustration showing a side view of a first section of the exemplary telescopic foundation screw pile of  FIG. 16 . 
           [0027]      FIG. 18  is a schematic illustration showing an exploded view of another exemplary telescopic foundation screw pile with a threaded rod connection. 
           [0028]      FIG. 19  is a schematic illustration showing a front view of a first section of the exemplary telescopic foundation screw pile of  FIG. 18 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1  is a schematic illustration showing an exploded view of an exemplary telescopic foundation screw pile  10 . The telescopic foundation screw pile  10  comprises a first section  12 , a second section  14 , a third section  16 , and a fourth section  18 . Although the number of sections shown in the exemplary telescopic foundation screw pile  10  comprises four sections, additional sections can be added as desired. In one embodiment, the telescopic foundation screw pile  10  comprises more than four sections. Alternatively, the telescopic foundation screw pile  10  can comprise less than four sections. In one embodiment, the telescopic foundation screw pile  10  comprises three sections. In another embodiment, the telescopic foundation screw pile  10  comprises two sections. 
         [0030]      FIG. 2  is a schematic illustration showing an enlarged view of a portion near the meeting place between the first section and the second section of the exemplary telescopic foundation screw pile  10  of  FIG. 1 . As shown in  FIGS. 1 and 2 , the first section  12  has a cone-shaped body  20  with a lower end  22  located at the tip side (or the narrower side) and an upper end  24  located at the opposite side (or the wider side) from the lower end  22 . 
         [0031]      FIG. 3  is a schematic illustration showing a side view of the exemplary telescopic foundation screw pile  10  of  FIG. 1 .  FIG. 4  is a schematic illustration showing a cross-sectional view taken along A-A of the exemplary telescopic foundation screw pile  10  of  FIG. 3 . The body  20  extends substantially rotationally symmetrically about a longitudinal axis  28  (see  FIG. 3 ), which at the same time defines the longitudinal direction of the body  20 . The body  20  is preferably hollow internally. 
         [0032]      FIG. 5  is a schematic illustration showing an enlarged view of a portion near the meeting place between the first section and the second section of the exemplary telescopic foundation screw pile  10  of  FIG. 4 .  FIG. 6  is a schematic illustration showing an enlarged view of the first section  12  of the exemplary telescopic foundation screw pile  10  of  FIG. 3 . In the present embodiment, the cone-shaped body  20  of the first section  12  is continuously tapered from the upper end  24  to the lower end  22 . In one embodiment, the degree of taping (i.e., the angle  38  formed between the longitudinal axis  28  and an outer contour  32  running approximately along the longitudinal direction of the body  20 ) is the same through the whole body  20 . Alternatively, the degree of taping can vary through the whole body  20 . In a preferable embodiment, at any point of the body  20 , the outer diameter at that point is greater than or equal to that at any point lower (i.e., closer to the lower end  22 ) and less than or equal to that at any point higher (i.e., closer to the upper end  24 ). 
         [0033]    In the present embodiment, the lower end  22  has a round opening  34 . In one embodiment, the opening  34  has a radius of less than one inch. Alternatively, the lower end  22  can have a cone-shaped head (not shown). In one embodiment, the head is made of metal. In a further embodiment, the metal is titanium. 
         [0034]    In the present embodiment, an annular flange  36  is attached to the upper end  24  of the body  20 . In the present embodiment, the flange  36  has a plurality of holes  46  (see  FIG. 2 ) for receiving bolts. In one embodiment, the number of the holes  46  is six. 
         [0035]    In the present embodiment, the body  20  of the first section  12  is surrounded by a helical screw thread  48 , which extends from the upper end  24  to the lower end  22  over the entire first section  12 . In another embodiment, the helical screw thread  48  does not cover the entire first section  12 . 
         [0036]    In the present embodiment, the helical screw thread  48  is joined to the body  20  via welds. Alternatively, the helical screw thread  48  and the body  20  can be formed together or attached by mechanical means. 
         [0037]    In the present embodiment, the body  20 , the flange  36 , and the helical screw thread  48  are made of metal. In one embodiment, the metal is solid steel. 
         [0038]      FIG. 7  is a schematic illustration showing an enlarged view of the second section  14  of the exemplary telescopic foundation screw pile  10  of  FIG. 3 . In the present embodiment, the second section  14  has a frustum-shaped body  50  with a lower end  52  and an upper end  54 . The body  50  extends substantially rotationally symmetrically about the longitudinal axis  28 , which at the same time defines the longitudinal direction of the body  50 . 
         [0039]    The body  50  is preferably hollow internally. In the present embodiment, the body  50  is continuously tapered from the upper end  54  to the lower end  52 . In one embodiment, the degree of taping (i.e., the angle  60  formed between the longitudinal axis  28  and an outer contour  62  running approximately along the longitudinal direction of the body  50 ) is the same through the whole body  50 . Alternatively, the degree of taping can vary through the whole body  50 . In a preferable embodiment, at any point of the body  50 , the outer diameter at that point is greater than or equal to that at any point lower (i.e., closer to the lower end  52 ) and less than or equal to that at any point higher (i.e., closer to the upper end  54 ). 
         [0040]    In the present embodiment, an annular lower flange  66  is attached to the lower end  52  of the body  50 . In the present embodiment, the lower flange  66  has a plurality of holes  78  (see  FIG. 2 ) for receiving bolts. In the present embodiment, the number of the holes  78  is six. In one embodiment, the lower flange  66  is joined to the body  50  via welds. Alternatively, the lower flange  66  and the body  50  can be formed together or attached by mechanical means. 
         [0041]    In the present embodiment, an annular upper flange  80  is attached to the upper end  54  of the body  50 . In the present embodiment, the upper flange  80  has a plurality of holes (not shown) for receiving bolts. In the present embodiment, the upper flange  80  has additional slots (not shown) for facilitating the connection of the pile  12  to a pile driving equipment (not shown) if the second section  14  is the last section of the pile  10 . 
         [0042]    In the present embodiment, the body  50  of the second section  14  is surrounded by a helical screw thread  94 , which extends from the upper end  54  to the lower end  52  over the entire second section  14 . In another embodiment, the helical screw thread  94  does not extends over the entire second section  14 . 
         [0043]    In the present embodiment, the helical screw thread  94  is joined to the body  50  via welds. Alternatively, the helical screw thread  94  and the body  50  can be formed together or attached by mechanical means. 
         [0044]    In the present embodiment, the body  50 , the flanges  66 ,  80  and the helical screw thread  94  are made of metal. In one embodiment, the metal is solid steel. 
         [0045]    In the present embodiment, the first section  12  and the second section  14  are merged by aligning the flange  36  of the first section  12  with the lower flange  66  of the second section  14 . Then, a fixing mechanism is used to merge the first section  12  with the second section  14 . In one embodiment, bolting is used to merge the first section  12  with the second section  14 . After the merge of the first section  12  and the second section  14 , the outer contour of the merged unit are preferably smoothly aligned so that a continuously taper outer contour is still formed from the upper end  54  of the second section  14  all the way to the lower end  22  of the first section  12 . 
         [0046]    The third section  16  and the fourth section  18  can have similar structure as that of the second section  12  except that they have different lateral dimension so as to keep a continuously taper outer contour of the telescopic foundation screw pile  10  when they are merged with the first section  12  and the second section  14 . 
         [0047]    Referring back to  FIGS. 3 and 4 , the second section  14  and the third section  16  can be merged by aligning the upper flange  80  of the second section  14  with a lower flange  72  of the third section  16 . Then, a fixing mechanism can be used to merge the second section  14  and the third section  16 . Similarly, the third section  16  and the fourth section  18  can be merged by aligning an upper flange  76  of the third section  16  with a lower flange  98  of the fourth section  18 . Then, a fixing mechanism can be used to merge the third section  16  with the fourth section  18 . After the merge of all sections  12 ,  14 ,  16 ,  18 , the outer contour of the telescopic foundation screw pile  10  forms a continuously taper outer contour from the upper end  96  of the fourth section  18  all the way to the lower end  22  of the first section  12 . 
         [0048]    Although the embodiments described earlier employ holes on the flanges  36 ,  66 ,  80 ,  72 ,  76 ,  98  for bolt connection, other configurations can also be used for connecting adjacent sections. For example, instead of the bolted connection, a plate connection (see  FIGS. 16 ,  17 ) or a threaded rod connection (see  FIGS. 18 ,  19 ) can be used. A more detailed description on the plate connection and the threaded rod connection will be provided hereafter. 
         [0049]      FIG. 8  is a schematic illustration showing an elevation view of another exemplary telescopic foundation screw pile  110 .  FIG. 9  is a schematic illustration showing a front view of the exemplary telescopic foundation screw pile  110  of  FIG. 8 . The telescopic foundation screw pile  110  comprises a first section  112 , a second section  114 , a third section  116 , and a fourth section  118 . Although the number of sections shown in the exemplary telescopic foundation screw pile  110  comprises four sections, additional sections can be added as desired. In one embodiment, the telescopic foundation screw pile  110  comprises more than four sections. Alternatively, the telescopic foundation screw pile  110  can comprise less than four sections. In one embodiment, the telescopic foundation screw pile  110  comprises three sections. In another embodiment, the telescopic foundation screw pile  110  comprises two sections. In one embodiment, the first section  112  can be a standalone pile. 
         [0050]      FIG. 10  is a schematic illustration showing a front view of the first section  112  of the exemplary telescopic foundation screw pile  110  of  FIG. 8 . The first section  112  has a cone-shaped body  120  with a lower portion  121 , a middle portion  123  and an upper portion  125 . The lower portion  121  and the middle portion  123  intersect at a joint place  127 . The middle portion  123  and the upper portion  125  intersect at a joint place  129 . A lower end  122  is located at the tip side (or the narrower side) of the lower portion  121  and an upper end  124  is located at the opposite side (or the wider side) from the lower end  122 . The three portions  121 ,  123  and  125  are shown for reference purpose. In the present embodiment, the body  120  is fabricated from one continuous tube and there can be no joints or welds on the tube. 
         [0051]    The body  120  extends substantially rotationally symmetrically about a longitudinal axis  128  (see  FIG. 9 ), which at the same time defines the longitudinal direction of the body  120 . The body  120  is preferably hollow internally. In the present embodiment, the lower portion  121  is continuously tapered from the joint place  127  to the lower end  122 ; the middle portion  123  is continuously tapered from joint place  129  to joint place  127 . In the present embodiment, the upper portion  125  maintains a constant diameter so that it can be placed in a spindle of a swaging equipment. Alternatively, the upper portion  125  can be continuously tapered from the upper end  124  to joint place  129 . Therefore, the body  120  of the first section  112  is continuously tapered from the upper end  124  to the lower end  122 . 
         [0052]    In the present embodiment, the degree of taping (i.e., the angle formed between the longitudinal axis  128  and an outer contour running approximately along the longitudinal direction of the body  120 ) are different among portions  121 ,  123  and  125 . In one embodiment, the degree of taping of the lower portion  121  is greater than that of the middle portion  123 . In addition, the degree of taping of the middle portion  123  is greater than that of the upper portion  125 . In a preferable embodiment, at any point of the body  120 , the outer diameter at that point is greater than or equal to that at any point lower (i.e., closer to the lower end  122 ) and less than or equal to that at any point higher (i.e., closer to the upper end  124 ). Alternatively the degree of taping can be the same through the whole body  120 . 
         [0053]    In the present embodiment, the lower end  122  has a round opening  134 . In one embodiment, the opening  134  has a radius of less than one inch. Alternatively, the lower end  122  can have a cone-shaped head (not shown). In one embodiment, the head is made of metal. In a further embodiment, the metal is stainless steel. Alternatively, the metal is aluminum or titanium. 
         [0054]    In one embodiment, the length in the longitudinal direction of the lower portion  121  is 12 inches; the length in the longitudinal direction of the middle portion  123  is 52 inches; and the length in the longitudinal direction of the upper portion  125  is 8 inches. 
         [0055]    In one embodiment, the outer diameter at the lower end  122  is 1.2 inches; the outer diameter at the joint place  127  is 3 inches; the outer diameter at the joint place  129  is 5 inches; and the outer diameter at the upper end  124  is 5 inches. 
         [0056]    In one embodiment, the degree of taping of the lower portion  121  is 4.3°. In one embodiment, the degree of taping of the middle portion  123  is 1.1°. 
         [0057]      FIG. 11  is a schematic illustration showing a cross-sectional view taken along B-B of the first section  112  of  FIG. 10 . In the present embodiment, an annular flange  136  is attached to the upper end  124  of the body  120 . In one embodiment, the annular flange  136  has a thickness of 0.5 inches. The flange  136  has an outer diameter  142  which is greater than the outer diameter of the body  120  at the upper end  124 . In one embodiment, the outer diameter of the body  120  at the upper end  124  is 5.8 inches. In one embodiment, the outer diameter  142  of the flange  136  is 8.1 inches. 
         [0058]    In the present embodiment, the flange  136  has a plurality of holes  146  for receiving bolts. In one embodiment, the number of the holes is six. In one embodiment, the flange  136  is joined to the body  120  via welds. Alternatively, the flange  136  and the body  120  can be formed together or attached by mechanical means. 
         [0059]    In the present embodiment, the body  120  of the first section  112  is surrounded by a helical screw thread  148 , which extends from joint place  129  to joint place  127  over the entire middle portion  123 . Alternatively, the helical screw thread  148  can extends from the upper end to the lower end  122  over the entire body  120 . 
         [0060]    In the present embodiment, the helical screw thread  148  is joined to the body  120  via welds. Alternatively, the helical screw thread  148  and the body  120  can be formed together or attached by mechanical means. 
         [0061]    In the present embodiment, the body  120 , the flange  136 , and the helical screw thread  148  are made of metal. In one embodiment, the metal is solid steel. 
         [0062]      FIG. 12  is a schematic illustration showing a front view of a second section  114  of the exemplary telescopic foundation screw pile  110  of  FIG. 8 . The second section  114  has a frustum-shaped body  150  with a lower portion  151 , a middle portion  153  and an upper portion  155 . The lower portion  151  and the middle portion  153  intersect at a joint place  157 . The middle portion  153  and the upper portion  155  intersect at a joint place  159 . A lower end  152  is located at the narrower side of the lower portion  151  and an upper end  124  is located at the opposite side (or the wider side) from the lower end  152 . The three portions  151 ,  153  and  155  are shown for reference purpose. In the present embodiment, the body  150  is fabricated from one continuous tube and there can be no joints or welds on the tube. 
         [0063]    In the present embodiment, the body  150  extends substantially rotationally symmetrically about a longitudinal axis (not shown), which at the same time defines the longitudinal direction of the body  150 . The body  150  is preferably hollow internally. 
         [0064]    In the present embodiment, the lower portion  151  is continuously tapered from the joint place  157  to the lower end  152 ; the middle portion  153  is continuously tapered from joint place  159  to joint place  157 ; and the upper portion  155  is continuously tapered from the upper end  154  to joint place  159 . In one embodiment, the body  150  of the second section  114  is continuously tapered from the upper end  154  to the lower end  152 . 
         [0065]    In the present embodiment, the degree of taping (i.e., the angle formed between the longitudinal axis  128  and an outer contour running approximately along the longitudinal direction of the body  120 ) are different among portions  151 ,  153  and  155 . In one embodiment, the degree of taping of the lower portion  151  is greater than that of the middle portion  153 . In addition, the degree of taping of the middle portion  153  is greater than that of the upper portion  155 . In a preferable embodiment, at any point of the body  150 , the outer diameter at that point is greater than or equal to that at any point lower (i.e., closer to the lower end  152 ) and less than or equal to that at any point higher (i.e., closer to the upper end  154 ). Alternatively the degree of taping can be the same through the whole body  150 . 
         [0066]    In one embodiment, the length in the longitudinal direction of the lower portion  151  is 8 inches; the length in the longitudinal direction of the middle portion  153  is 52 inches; and the length in the longitudinal direction of the upper portion  155  is 8 inches. 
         [0067]    In one embodiment, the outer diameter at the lower end  152  is 5 inches; the outer diameter at the joint place  157  is 5.3 inches; the outer diameter at the joint place  159  is 7 inches; and the outer diameter at the upper end  154  is 7 inches. 
         [0068]      FIG. 13  is a schematic illustration showing an enlarged view of a portion near the lower end of the second section  114  of  FIG. 12 . In the present embodiment, an annular lower flange  166  is attached to the lower end  152  of the body  150 . In one embodiment, the lower flange  166  has a thickness  168  of 0.6 inches. The lower flange  166  has an outer diameter  174  which is greater than the outer diameter  170  of the body  150  at the lower end  152 . In the present embodiment, the size of the outer diameter  174  of the lower flange  166  of the second section  114  is substantially the same as the size of the outer diameter  142  of the flange  136  of the first section  112 . In one embodiment, the outer diameter  174  of the flange  166  is 8.1 inches. 
         [0069]    In the present embodiment, the lower flange  166  has a plurality of holes  178  for receiving bolts. In one embodiment, the number of the holes  178  is six. In the present embodiment, the lower flange  166  is joined to the body  150  via welds. Alternatively, the lower flange  166  and the body  150  can be formed together or attached by mechanical means. 
         [0070]      FIG. 14  is a schematic illustration showing an enlarged view of a portion near the upper end of the second section  114  of  FIG. 12 . In the present embodiment, an annular upper flange  180  is attached to the upper end  154  of the body  150 . In one embodiment, the upper flange  180  has a thickness  182  of 0.6 inches. The upper flange  180  has an outer diameter  188  which is greater than the outer diameter of the body  150  at the upper end  154 . In one embodiment, the outer diameter  188  of the upper flange  180  is 10.1 inches. 
         [0071]      FIG. 15  is a schematic illustration showing a cross-sectional view taken along C-C of the exemplary telescopic foundation screw pile  112  of  FIG. 12 . In the present embodiment, the upper flange  180  has a plurality of holes  192  for receiving bolts. In one embodiment, the number of the holes  192  is ten. In one embodiment, the diameter of the holes  192  is 0.7 inches. The upper flange  180  has additional slots  187  for facilitating the connection of the pile  114  to a pile driving equipment (not shown). In one embodiment, the upper flange  180  is joined to the body  150  via welds. Alternatively, the upper flange  180  and the body  150  can be formed together or attached by mechanical means. 
         [0072]    In the present embodiment, the body  150  of the second section  114  is surrounded by a helical screw thread  194 , which extends from joint place  159  to joint place  157  over the entire middle portion  153 . Alternatively, the helical screw thread  194  can extends from the upper end  154  to the lower end  152  over the entire body  150  of the second section  114 . 
         [0073]    In one embodiment, the helical screw thread  194  is joined to the body  150  via welds. Alternatively, the helical screw thread  194  and the body  150  can be formed together or attached by mechanical means. 
         [0074]    In one embodiment, the body  150 , the flanges  166 ,  180  and the helical screw thread  194  are made of metal. In a further embodiment, the metal is stainless steel. Alternatively, the metal is aluminum or titanium. 
         [0075]    In the present embodiment, the first section  112  and the second section  114  are merged by aligning the flange  136  of the first section  112  with the lower flange  166  of the second section  114 . Then, a fixing mechanism is used to merge the first section  112  with the second section  114 . In one embodiment, bolting is used to merge the first section  112  with the second section  114 . After the merge of the first section  112  and the second section  114 , the outer contour of the merged unit are preferably smoothly aligned so that a continuously taper outer contour is still formed from the upper end  154  of the second section  114  all the way to the lower end  122  of the first section  112 . 
         [0076]    The third section  116  and the fourth section  118  can have similar structure as the second section  114  except that they have different lateral dimension so as to keep a continuously taper outer contour of the telescopic foundation screw pile  110  when they are merged with the first section  112  and the second section  114   
         [0077]    Referring also to  FIG. 8 , the second section  114  and the third section  116  can be merged by aligning the upper flange  180  of the second section  114  with the lower flange  172  of the third section  116 . Then, a fixing mechanism can be used to merge the second section  114  and the third section  116 . Similarly, the third section  116  and the fourth section  118  can be merged by aligning the upper flange  176  of the third section  116  with the lower flange  198  of the fourth section  118 . Then, a fixing mechanism can be used to merge the third section  116  with the fourth section  118 . After the merge of all sections  112 ,  114 ,  116 ,  118 , the outer contour of the telescopic foundation screw pile  110  forms a continuously taper outer contour from the upper end  196  of the fourth section  118  all the way to the lower end  122  of the first section  112 . 
         [0078]    Although the embodiments described earlier employ holes on the flanges  136 ,  166 ,  180 ,  172 ,  176 ,  198  for bolt connection, other configurations can also be used for connecting adjacent sections. For example, instead of the bolted connection, a plate connection (see  FIGS. 16 ,  17 ) or a threaded rod connection (see  FIGS. 18 ,  19 ) can be used. A more detailed description on the plate connection and the threaded rod connection will be provided hereafter. 
         [0079]    The manufacturing process for making the telescopic foundation screw piles  10  and  110  will be described in further details hereafter. Tubes of different diameter can be selected as fabricated tubes. For example, tubes of HSS “Hollow Structural Steel” ASTM A-500 Grade A or B can be used. For example, a 5 inch diameter round tube can be selected for the first section; a 7 inch diameter round tube can be selected for the second section, etc. Then the tubes can be cut into desired section length. Then, a swaging process can be performed on the sectioned tube to reduce its diameter to form a continuously taper tube. For example, the 7 inch diameter round tube for the second section can be swaged to have a diameter of 7 inch diameter at the upper end and a 5 inch diameter at the lower end with a continuously taping. The swaging process can be either hot swaging or cold swaging. 
         [0080]    The connection between sections can be performed by a flange to flange bolted connection as described previously in connection with the telescopic foundation screw piles  10  and  110 . Individual flanges can first be fabricated to their corresponding geometry in a factory. Flanges can then be welded to the sections at the factory. The first section has one flange at its upper end. The other sections have two flanges, one at the lower end and one at the upper end. Then, the sections are installed in the field by bolting the corresponding flanges from connecting sections. The upper flange of the last (the up most) section can have slots for connecting the pile to a pile driving equipment. 
         [0081]    Alternatively, the connection between sections can be performed by a plate connection.  FIG. 16  is a schematic illustration showing a front view of a first section  212  of another exemplary telescopic foundation screw pile  210  with a plate connection.  FIG. 17  is a schematic illustration showing a side view of the first section  212  of the exemplary telescopic foundation screw pile of  FIG. 16 . Although only the first section  212  is shown herein, the telescopic foundation screw pile  210  can comprise multiple sections similarly to that of the telescopic foundation screw pile  10  or  110 . In addition, the configuration of the telescopic foundation screw pile  210  can be similar to that of the telescopic foundation screw pile  10  or  110  except for the connection scheme. Referring to  FIGS. 16 and 17 , a plate  220  with holes  224  can be fabricated in the factory and welded to the sections. Preferably, the plate  220  is welded only on the top portion  222  of each of the individual section. The bottom portion of each section (except the first section) has holes on the body. The corresponding sections can be connected via bolts with positions predetermined in the sections. Because there is no extension protruded out of the body as the flange has, the plate connection is preferred for installation in soils that the use of flanges would cause difficulty in penetration. The upper portion of the last section can have slots for connecting the pile to a pile driving equipment. 
         [0082]    Alternatively, the connection between sections can be performed by a threaded rod connection.  FIG. 18  is a schematic illustration showing an exploded view of another exemplary telescopic foundation screw pile  310  with a threaded rod connection.  FIG. 19  is a schematic illustration showing a front view of a first section  312  of the exemplary telescopic foundation screw pile  310  of  FIG. 18 . Although only the first section  312  and the second section  314  are shown herein, the telescopic foundation screw pile  310  can comprise multiple sections similarly to that of the telescopic foundation screw pile  10  or  110 . In addition, the configuration of the telescopic foundation screw pile  310  can be similar to that of the telescopic foundation screw pile  10  or  110  except for the connection scheme. Referring to  FIGS. 18 and 19 , a rod  320  with threads (not shown) can be machined with a flange  330  in the factory. The flange  330  is preferably located at the middle portion of the rod  320  so that threads are on both ends of the rod  320 . The inner surface  326 ,  328  of the top portion and bottom portion (except for the first section) of each section can be threaded in the factory. Field installation can be done by screwing the sections  312 ,  314  to be connected by using the threaded rod  320 . Because the threaded rod connection has a flange  330  that typically does not protrude more than a quarter inch from the body of tube sections  312 ,  314 , the threaded rod connection would not cause much difficulty in pile penetration. The upper portion of the last section can have slots for connecting the pile to a pile driving equipment. 
         [0083]    Although the flange to flange bolted connection, the plate connection, and the threaded rod connection described hereinbefore are used mutually exclusive in different embodiments, a pile can be fabricated and installed with more than one connection schemes if desired. 
         [0084]    The telescopic foundation screw piles  10 ,  110 ,  210 ,  310  described herein have several advantages. First, there is no requirement of pre-drill or digging to the soils for installation of the telescopic piles. Therefore, there is no potential spoils or cross contamination. In addition, there is no requirement of refilling of concrete or grout, resulting in a fast, simple, low cost and ease of use installation processing. 
         [0085]    In addition, the use of telescopic piles with variable number of sections, which can be flexibly chosen, based on the desired depth of the foundation, can reduce the cost of materials. In addition, energy for drilling can be reduced. 
         [0086]    In addition, the continuously taping outer contour of the telescopic piles provides a uniformly lateral pressure to the soils in terms of the depth of the foundation, resulting in an improved soil density around the installed telescopic piles so as to achieve a higher load capacity. 
         [0087]    In addition, the continuously taping outer contour of the telescopic piles provides an increased skin friction. Nordlund developed a method of calculating skin friction based on field observations and results of several pile load tests in cohesionless soils. Several pile types were used, including timber, H type steel, pipe, monotube, etc. The method accounts for pile taper and for differences in pile materials. Nordlund indicates that the unit skin friction is increased by a factor of at least 1.5 for an angle of taper of 0.5 degrees (approximately 1%). (See page 119, M. J. Tomlinson, Pile Design and Construction Practice, fourth edition, Tayler and Francis, Oxon, UK, 1994.) 
         [0088]    While the invention has been described in connection with specific examples and various embodiments, it should be readily understood by those skilled in the art that many modifications and adaptations of the invention described herein are possible without departure from the spirit and scope of the invention as claimed hereinafter. Thus, it is to be clearly understood that this application is made only by way of example and not as a limitation on the scope of the invention claimed below. The description is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains.