Load Transfer System

Abstract

This is a new type of pile foundation for support of structures. It uses a new method of forming concrete around the steel rebar prior to installing the rebar. Concrete is molded in an undulating fashion to improve load transfer to the adjacent hole backfill. The backfill is densified in place and grouted to maintain the dense configuration. The grouting is injected into an unlined hole. If temporary casing is used during drilling, it is removed prior to grouting. The basic premises are that grouting the hole backfill to the surrounding soil provides a better load transfer at that interface. And, beyond a few inches past the steel rebar, grouted dense sand and gravel are adequate for the load at that point. Timing of the grouting is more flexible than typical ready-mix concrete delivery systems. This method also allows for real time testing of the pile capacity.

Claims

1. First claim of this application is that the pile will function the same if the concrete is only placed around the rebar for a few inches, and the remainder of the hole is filled with dense sand and gravel. Due to the lower stress level as discussed above the grout locking the dense sand and gravel in-place does not need to be as strong as Portland cement. The other advantage to grout is a quick set time allows for real-time testing to ensure the load capacity of the pile. What is necessary is to mold the concrete in an undulating fashion so that the sloping surface places a compressive load on the dense sand and gravel. Second claim is the grout will penetrate the surrounding soil thus giving the pile the capacity of a larger diameter then the drill size of the hole. The amount of penetration is dependent upon the soil condition and the type of grout that is being used. Third claim The load transfer process described herein works just as well in reverse. The transfer of load from soil to steel rebar is just as efficient as load going from rebar to foundation soil. This load transfer makes it possible to support soil where lateral support soil is being removed. This commonly occurs with temporary or permanent excavations. If the soil adjacent to the proposed cut is first vertically supported then the cut is stable because the supported soil has become a gravity wall. Fourth claim using multiple piles drilled and set in an area adjacent to a proposed cut for a retaining wall will result in lower load on the wall. This is due to the grouted piles providing vertical support for the soil adjacent to the cut. Vertical support for the soil adjacent to the cut reduces or eliminates the driving force that creates the load on the retaining wall, temporary shoring. In the case of temporary shoring it is possible to use threaded rebar and mold the concrete around a threaded sleeve. Once the temporary excavation is backfilled the threaded rebar can be unscrewed from the shoring pile and reused. Fifth claim The same load transfer system can be accomplished using smaller bent rebar attached and around the main load carrying rebar. Two examples of this type of system are provided herein. One uses small rebar twisted to form a spiral node and the other uses multiple bent rebar to form a node. The main advantage to these systems are they can be formed on site using standard rebar and be put into use immediately.

Description

[0006] The attached figures listed here show how this will work:

[0007] FIG. 1 Cut view of section of pile in hole showing transfer of external load to soil.

[0008] FIG. 2 Cut view of complete pile with modified rebar transferring load to soil.

[0009] FIG. 3 Cut view of multiple piles for moment frame to provide temporary stabilization.

[0010] FIG. 4 Enlarged perspective view of moment frame system.

[0011] FIG. 5 Cut view of multiple piles with modified rebar for permanent ground stabilization.

[0012] FIG. 6 Cut view of multiple piles forming a gravity wall in existing soil.

[0013] FIG. 7 Cut view of common fill gravity wall system for comparison with FIG. 6.

[0014] FIG. 8 Perspective view of trench stabilization using modified rebar and random fill.

[0015] FIG. 9 Perspective view of multiple stabilization trenches prior to excavation.

[0016] FIG. 10 Perspective view of FIG. 9 after vertical cut is complete.

[0017] FIG. 11 Cut view of alternate method to the modified rebar system.

[0018] FIG. 12 Two rebar that will become an alternate system of nodes to transfer load.

[0019] FIG. 13 Cut view of multiple bent rebar forming node using FIG. 12 design.

[0020] The claim of this patent is if the order of the CIDH pile construction is changed the above listed problems can be eliminated or minimized. The basic idea is to cover the steel rebar with an undulating coating of concrete prior as shown in FIG. 1 to placing into the hole. This ensures that each rebar has the minimum concrete cover. The rebar is lowered into the hole along with the grout/water pipes and the vibratory equipment. This is shown on FIG. 1 the rebar 1_is shown inside the bore hole with limits 9. The process in FIG. 1 has reached the grouting phase as demonstrated by the grout 13 flowing out of the grout pipe 11. Sand 7 and gravel 6 have been densifies by the vibrator 12. FIG. 2 presents a section view of a modified rebar 1 in a piles hole that is filled with sand 7 gravel 6 and grout_13. FIG. 2 also shows how the load 3 is transferred from the rebar 1 to the molded concrete 2 through load transfer 14 along the ribs of the rebar. Then the load is transferred from the concrete to the sand 7 and gravel 6 that will be grouted 13 to improve its load carrying capacity. Then the load is transferred 15 from the pile_to the grouted soil 10. The soil 10 has been improved where the grout 8 has intruded. Leaving the hole unlined or the casing removed increases the likely hood that the weakest layers in the soil 10 will be improved by allowing the grout to flow freely. It should be noted that either during or after backfilling filling the hole the same pipes 11 can be used to wet the granular material and the vibratory device 12 can densify the material to ensure proper load transfer from the coated rebar to the foundation soil beyond the hole. To complete the process liquid grout 13 would then be injected into the hole. Grouting has two purposes; 1) the grout will lock the sand and gravel in place to maintain its high-density configuration, and 2) under pressure the grout will. flow out into the surrounding soil. Filling the majority of the hole with granular material and grouting changes the interface 9_into a gradual change from one soil type to another. This would greatly improve the contact between the drilled hole and the supporting soil 10 formation. Which is the primary limiting factor when determining the pile's capacity. This is typically described as the adhesion factor between dissimilar materials such as soil/steel and soil/concrete.

[0021] The ground improvement and grouting industry have developed a large number of grouting materials. This includes what is known as “granddaddy grout”. That is a simple mixture of water and Portland cement and possibly fly ash to help it flow. The choice of grout and/or granular fill is not a subject of this patent application. The system proposed herein will work with a wide verity of grout and granular fill material. The choice of those materials for any given project would depend upon many factors such as desired load capacity, cost, and availability of materials.

[0022] It is helpful to look at the basic aspects of how a CIDH pile functions. The Youngs modulus of the steel is so large compared to the concrete, or the modulus of the soil that it carries all of the load initially. Moving down the pile the load is transferred to the concrete which ultimately transfers it to the soil. This compressive load transfer inside the concrete is primarily through the gravel portion of the concrete mix. This is why densification of wet concrete is so important. The individual gravels must be in contact with the adjacent gravel. Then at the foundation soil/concrete interface the load must be transferred from the outer surface of the concrete to the soil which has been disturbed by the drilling process.

[0023] Examination of the load transfer finds that the high strength of the concrete is only utilized at the steel rebar/concrete interface. As the load moves out away from the rebar it becomes spread out over a larger and larger area. Thus, the same load is carried by a larger volume of concrete. This results in lower and lower levels of stress per unit of concrete. The end result is that the majority of the concrete is underutilized, and its primary function is to be filler material. FIG. 2 again shows that the lower pressure can be carried by sand 7 and gravel 6 zone where they are locked by grout 8 in a dense configuration. This system will work just as efficiently as typical as a CIDH pile.

[0024] For concrete the primary purpose of the sand and cement is to hold the gravel size rock in-place. Therefore, a similar product can be produced by first installing dense sand and gravel and then injecting a cementing or grouting agent under pressure. The primary limitation to this “out of order process” is the stress level at the rebar to concrete interface where load transfer 14 occures. The ribs on the rebar are intended to work with wet concrete forming around them. This can be overcome by pouring concrete around the rebar and allowing it to harden prior to installing the rebar in the pile hole. At this point in the process the key to successful load transfer is provided by the shape of the concrete. Tests to date indicate that if the concrete is molded in an undulating shape there is very good load transfer between the concrete and the dense sand and gravel material used to finish filling the hole.

[0025] It has become obvious that the majority of the concrete in a CIDH pile is underutilized. Once the load has been transferred from the steel to the concrete then a lower strength filler material such as dense sand and gravel that is grouted in place will suffice. Therefore, the grouting process results in a superior overall product because it improves the pile to soil contact. Given the variable nature of natural soil formations it is essential that all casing be removed prior to grouting. This is to ensure that the grout will encounter and improve all weak layers along the pile/soil interface.

[0026] Given the tendency for grout to travel out into the soil beyond the limit of the drilled hole the end result is a pile that functions like it is larger than the initial drill size of the hole. Thus, a small diameter pile could have the same capacity as a larger pile. FIGS. 3 and 4 present a condition where small diameter piles would have a great advantage over typical CIDH piles. The fact that the grout will extend beyond drilled hole allows for greater spacing in shoring piles. Also, for temporary conditions the molded concrete 2 could be designed such that the steel rebar 1 can be removed and reused when the excavation has been backfilled, and the steel is no longer needed. The details of how that can be accomplishes will be discussed in the detailed description of the Figures. The primary claim of this patent is that unstable ground conditions can be stabilized by this method of load transfer using modified steel rebar 1.

[0027] For a permanent stabilization project FIG. 5 shows how modified rebar 1 in grouted 8 holes 17 can be configured to form the equivalent of a gravity retaining wall. This is accomplished by tying the piles together with a concrete slab 23 at the top of the wall so that the soil 10 is now a single mass described in the detailed figure description of FIG. 6 and FIG. 7. The FIG. 7 shows a typical method for building a gravity wall using horizontal ties 30 in a new compacted fill 29. This method of construction requires a large amount of earth moving to make the back cut 28, and typically the new compacted fill 29 needs to be imported due to the fact that the horizontal reinforcement 30 only works with specific soil types. FIG. 6 shows the same gravity wall constructed from the top down prior to the excavation of the original ground suggested by line 27. For this method to work the load created by the excavation needs to be absorbed by the upper section of the piles and transferred to stable ground at a lower elevation.

[0028] Another use for the modified rebar 1 with its undulating concrete cover 2 is presented on FIG. 8, FIG. 9, and FIG. 10. Here the modified rebar_1 is placed horizontally or close to horizontal in a trench. Then the trench is backfilled to or close to the original ground surface. Then the fill mass around the modified rebar 1 can be grouted using the grout pipes 11 that were placed within the fill. The fill mass could include cobble and boulder size rocks 32 and/or demolition concrete 33. These would be placed in a matrix of sand 7 and gravel 6. It is this granular soil matrix that will be grouted into a solid mass. This solid mass is held together by the modified rebar 1 which will carry tensil load. That load is transferred from the surrounding soil 10 through the grouted fill mass to the undulating concrete 2 to the rebar 1. This is essentially how steel reinforced concrete works. The difference with this is the overall load is small enough that strength of concrete is only needed around and along the steel rebar 1. FIG. 9 shows the line 34 of the proposed vertical cut. The advantage to grouting the fill is that the grout will also penetrate adjacent soil 10. This will make a better connection between the soil 10 and the grouted fill trench that is held together by the steel rebar. The back section of the trench will act as an anchor where it is contact with stable soil 10.

[0029] FIG. 10 shows the condition where the vertical cut 39 is complete. When vertical cuts are made the soil 10 behind the face moves down and out into the cut ground. With properly spaced filled trenches the movement of the soil 10 out of the vertical cut 39 will be prevented as the trenches will act as anchors. In addition to the trenches FIG. 10 presents the possibility of drilled and filled piles 17 that will transfer the load to deeper stable soil 10. For this condition the load on the wall face supporting cut 39 is minimal.

[0030] For the purpose of making a load transfer system it is not necessary to use concrete nodes on the rebar. Where the corrosion of the rebar is not a concern then the nodes could be fashioned by making spiral shaped rebar around the central load bearing steel. FIG. 11 shows spiral rebar welded to a central tube. The central tube could be used to transmit the grout 13 through holes 38. Also, the tube could transmit and transfer the load 3 to the spiral shaped rebar. The load would be transferred from the spiral rebar to the grouted gravel and then to the surrounding soils along a path shown as the arrow 4. Again, the load transfer is improved by grout 8 penetrating the soil 10. Another method simpler than spiral shaped nodes is bent small diameter rebar 36 laid alongside the load bearing rebar 1 as shown on FIG. 12. When grouped together they form a node as shown on FIG. 13. This figure shows a node where inside the rebar is a net to hold the gravel 6 inside the node. As with the other nodes the remainder of the fill is held in-place by grout 13 delivered by grout tube 11. The end result is load 3 is transferred to the node rebar 36 and ultimately through the gravel along the arrow 4. [0031] The following provides a more in-depth description of the enclosed figures. These figures and the descriptions here in are intended to provide a novel approach to transferring load from one zone of soil that needs support to a stable zone located close by. As with other existing methods this design relies upon steel rebar to carry most of the load. The difference with this approach is to use a minimal volume of concrete that can be applied any_time prior to the use of the rebar 1. The advantage is that the grout can be applied at any time and if it has a short set time then it can be load tested quickly to ensure that it will function as designed. When Portland cement concrete is used it typically develops the majority of its strength over a period of weeks.

FIGURES

[0032] FIG. 1

[0033] This figure shows the basic design and operation of the modified rebar. This shows the undulating concrete molded 2 around two adjacent rebar 1. It should be noted that the modification claimed herein is not limited to concrete. Other variations are covered later in this submittal. What is claimed as that it is necessary for the covering to have an undulating shape. As shown, where more than one rebar 1 is required the undulating shapes 2 can be aligned out of phase to improve the connectivity. This configuration is also a way for two rebar 1 to be spliced together. The load 3 is delivered to the system through the rebar 1. Said load is then transferred from the rebar 1 to the molded concrete 2 by friction 14 along the ribs of the rebar 1. Load is then transferred out of the molded concrete 2 primarily across the sloping face 5 of the undulation. The sloping face 5 will transfer the load to the adjacent material. The adjacent material may be another concrete mold 2, gravel 6, sand 7, or solid grout 8. The load passes through several mediums to reach the edge of the boring 9. At that point like with all other cast in drill hole piles the load is transferred to the surrounding soil 10. Following the principal of physics, that the stiffest element carries the vast majority of the load. In this case that would be the densified gravel 6. The primary purpose of the sand 7 and solid grout 8 are to hold the gravel 6 in place. This is why the order of construction is important. First the saturated sand 7 and gravel 6 are vibrated into a dense configuration. Then the liquid grout 13 is injected to lock the dense sand 7 and gravel 6 into place. This is done by first injecting water into the filled boring through the pipe 11 and vibrating the sand 7 and gravel 6 into a dense configuration. This can be accomplished using a typical concrete vibrator 12. As the wet mix of sand 7 and gravel 6 become dense then the vibrator 12 is withdrawn. Depending upon site conditions pipe 11 could be used to withdraw, excess water from the boring. Once the sand 7 and gravel 6 are in a dense configuration the liquid grout 13 can be injected primarily to lock the sand 7 and gravel 6 into place. Because the boring is not lined or cased the grout 13 will seep out beyond the edge of the boring 9. This will improve the contact and load transfer at the interface between the edge of boring 9 and the surrounding soil 10. Once the liquid grout 13 has flowed to its limit it will solidify into solid grout 8. This completes the load transfer process from load 3 to the surrounding soil 10. As will be shown in additional figures it is possible to reverse this load transfer process from surrounding soil 10 that needs support. The weight of soil 10 can be transferred to rebar 1 which will carry it as load 3 to a depth where it can be transferred back to a soil 10 layer that can provide support.

[0034] FIG. 2

[0035] This figure shows a completed pile that is subject to an external load 3. The grout pipes 11 are left behind after the piles has been completed. As shown the load is transferred from the rebar 1 to the node 2 along the ribs of the rebar 1. From there it passes through the material of the node 2 to the dense sand 7 and gravel 6, that is locked in place by the solid grout 8. This is shown by the arrows 4 where the sloping face 5 is placing a compression load of the dense sand 7 and gravel 6. The load then is delivered to the surrounding soil 10 which has been improved by the solid grout 8. Because the hole is unlined at the time that the liquid grout 13 is injected into the system it is free to flow into the weakest zones of the surrounding soil 10. This action of improving the weakest zones causes the overall strength of the surrounding soil 10 to be improved. As discussed above the weakest interface between a pile 17 and the supporting medium is at the edge of the pile 9. Leaving the pile unlined provides the greatest possibility that this interface will be improved.

[0036] FIG. 3

[0037] This figure shows how these piles could be used to support a temporary excavation. By tying the piles together, a moment frame can be constructed. Unlike the pile presented in FIG. 2 these piles are not subjected to structural vertical load at the top of the pile. Instead the soil provides the load as the excavation is made. The removal of lateral support during the excavation causes adjacent soil to move down and into the excavation. This generates soil load 15 at the soil/pile interface. Unless there is an anomaly in the surrounding soil 10 creating a dominant plane of weakness, the natural initial movement is down along a steep failure plane. This is what generates the soil load 15. This results in a vertical load being placed on the dense grouted 8 sand 7 and gravel 6 of the pile. This same load 15 is then transferred as a compression load 19 primarily at the up facing sides 18 of the undulating node 2. From there the load is transferred to the steel rebar 1 at the interface 14 between concrete node 2 and the rebar 1. The method of pile construction described herein would be particularly well adapted to provide support for this condition. This is due to the grouting 8 of the soil and the shape of the undulating nodes. The load 15 is now carried by the stiffest element, that is the rebar 1 down to the supported soil 10 where it is transferred from rebar 1 to concrete node 2 to dense sand 7, gravel 6 and grout 8. From there across the pile/soil interface 9 to the surrounding soil 10. This vertical support of the soil along with lateral support provided by the multiple pile moment frame 20 will greatly reduce the load on temporary shoring. For temporary shoring the rebar 1 could be threaded rebar which if placed in a sleeve prior to forming the nodes would be removable when the project is complete. Given the vertical capacity of the piles, this would improve the excavations shoring ability to support traffic load close to the excavation. The main intent is to create a safe working condition for installing a utility 21, which typically require a deeper excavation to make room for the sand bedding 22.

[0038] FIG. 4

[0039] This is a close up showing a moment frame 23 that ties two piles 17 together. The rebar 1 shown are threaded which also can function as bolts to help attach the moment frame 23 to the piles 17. The drawing also shows a cut away view of the pile 17. It should be noted that the piles 17 as shown are not complete or ready for service as the grouting is not complete.

[0040] FIG. 5

[0041] This shows another use for this pile 17 system. Using multiple rows of piles 17 can result in the formation of a gravity retaining wall. At the present time gravity walls are built from the bottom of a temporary excavation using select compacted fill with horizontal ties. That method uses the solid mass of the reinforced fill to hold the remaining soil in-place. The method proposed herein claims that by using numerous small piles 17 that provide vertical support to the existing soil 10 the soil closest to a proposed cut or retaining wall will function the same as a gravity wall. Thus, the soil 10 closest to the cut or wall that typically requires support is now self-supporting. The piles 17 have turned the problem into the solution. Given that these piles are not large enough to be soldier piles they do need to be tied together to function as a unit. Given that the entire rebar 1 does not need to be covered with nodes 2 makes it possible to use the upper part of the rebar 1 to tie the piles 17 together. This system of tying the piles 17 together could be either a concrete slab or grade beams 24. The same slab or grade beam system 24 could also be used to help support the wall face 25 by tying the wall rebar 1 to the pile 17 rebar 1. With the soil 10 self-supporting the wall 25 only needs to provide erosion control. Also, the wall 25 needs to support the sand 7 fill above the back drain 26.

[0042] FIG. 6

[0043] This shows an idealized section of a gravity wall created by installing piles 17 in close formation as discussed in FIG. 5. As described in FIG. 5 the piles 17 need to be installed prior to making the excavation for the retaining wall 25. A typical original ground surface 27 is shown in front of the retaining wall 25. The vertical piles 17 have created a gravity wall within the boundary line 26. The vertical soil 10 load is transferred to the deeper soil 10 below line 26. This system eliminates the need for excavation and backfill with reinforced select fill soil.

[0044] FIG. 7

[0045] This shows the typical excavation and reinforced fill soil 29 for the construction of a gravity wall. The excavation removes the soil 10 to the back cut limit 28, which is very similar to the gravity wall boundary line 26 in FIG. 6. The manufactures of the fill soil reinforcing strips 30 have developed methods to calculate the proper and safe back cut limit 28. This determines the size and volume of the fill soil 29 and the length and vertical spacing of the fill soil reinforcing strips 30. What is claimed here is that stabilizing the existing soil 10 would require piles 17 to support and unify the soil 10 into semisolid mass that will function as a gravity retaining wall. The primary advantage of using piles 17 is that it does not require the mass grading and earth moving needed for the method outlined in FIG. 7.

[0046] FIG. 8

[0047] Given that the rebar 1 is modified by shaping nodes 2 around the rebar prior to its use allows for other uses. FIG. 8 shows a perspective view of a backfilled trench with a cut way section to show the inside of the trench. The purpose of the trench is to improve the overall stability of the existing soil 10 around the trench. In this embodiment the rebar 1 modified with nodes 2 have been placed horizontally in the trench as it was backfilled. The backfill could include inert demolition debris 33 along with sand 7 and gravel 6 fill. As the trench is backfilled grout pipes 11 are inserted in the fill. During, or at the completion of trench 31 filling water and vibratory equipment can be used to densify the fill. The grout pipes 11 could be used for water injection. During, or at the completion of trench filling liquid grout 13 can be injected into the densified mix of debris 33, sand 7 and gravel 6. The purpose is for grout 8 to fill the void spaces between the debris 33, sand 7 and gravel 6 and flow out beyond the trench 31 to tie the soil 10 to the trench 31. The overall process is to create a rebar 1 reinforced slot in the ground with the minimum excavating and earthmoving.

[0048] FIG. 9

[0049] This figure shows a continuous level soil 10 surface where a proposed excavation 34 is planned. To improve the stability of the proposed excavation 34 trenches 31 have been excavated perpendicular to the alignment of line 34. It should be noted that the alignment of the trenches 31 does not require them to be perpendicular to the proposed excavation 34. This depiction of the modified rebar 1, and the fill is in the process of backfill trenches 31. It should be noted that the modified rebar 1 can be laid in the partially filled trench 31 at an angle, if a horizontal alignment is not desired. Where needed piles 17 can be added to improve the stability of the backcut soil 10 that will remain after the excavation 34 is mad along the dashed line.

[0050] FIG. 10

[0051] This figure shows the completed excavation supported by filled and grouted trenches 31 reinforced by rebar 1 covered by nodes 2. The soil 10 along the cut face line 34 is supported horizontally by the filled trenches 31 and vertically by the piles 17. For analyses purposes, the stability of a typical cut is a two-dimensional analysis. The advantage of this condition is the stability analysis is now a three-dimensional analysis with filled trenches 31 providing additional stability to the overall cut slope. For localized stability piles 17 can be added along the cut 34 between the trenches 31.

[0052] FIG. 11

[0053] This presents a different method of creating a node 2 along a rebar 1. As shown the center rebar has been replaced with an injection pipe 11. Two or more small rebar 36 are bent to form a spiral around the center pipe 11. These smaller rebar 36 are attached to the pipe 11 by welding 37. In this embodiment the grout pipe 11 serves two purposes. First, it is the method of providing water or grout and with multiple injection holes 38 that can be closed off using a method known as a tube-a manchette system. Second the pipe 11 is sufficient to support axel load 3. The load 3 is transferred to the small bent rebar 36 through the weld 37. The spiral shape is filled with gravel 6 which extends beyond the spiral bent rebar 36. The gravel 6 is densified and locked into place by the solid grout 8 that was originally injected into pile 17 through the injection hole 38. Again, the slope of the bends in the small rebar 36 impart a portion of the original load 3 to the gravel 6 in the form of a compression load 4. The grouted 8 gravel 6 transmits the compression load 4 through the gravel 6 to the surrounding soil 10. The interface along edge of the drilled hole 9 is improved by the gravel 6 being densified and pushed into the surrounding soil 10. What is clamed herein is that all of the load transfer systems described in FIGS. 1 through 10 can also be done using the spiral rebar 36 and the modified injection pipe 11.

[0054] FIG. 12

[0055] This figure shows two rebars. On is a strait rebar 1 and the second is a smaller bent rebar 36. The purpose of this figure is to show how a node 2 can be made using standard rebars. The node 2 requires several of these bent rebars 36 attached to the strait rebar 1. If the attachment is done by welding then the strength of the strait rebar 1 may be reduced. However, analyses should be performed to determine how much load an individual node 2 would be transferred from rebar 1 to the soil 10.

[0056] FIG. 13

[0057] This figure shows a group of small bent rebar 36 form a node 2 around the primary rebar 1. This system would have a node 2 filled with gravel 6 which are held in place by a screen. Similar to the previous node 2 systems described in FIGS. 1 through 10 this node would also be held in place by grout 8. The load 3 is transferred from the main rebar 1 to the smaller bent rebar 36.

[0058] The rebar 36 transfers the load to both the gravel 6 inside the node 2 and the pile 17 gravel 6 fill. The load is disseminated through the gravel 6 to the soil 10. The load transfer is improved by the densified gravel 6 pressed into the soil 10 and possible grout 8 intrusion into the soil 10. What is clamed herein is that all of the load transfer systems described in FIGS. 1 through 10 can also be done using the bent rebar 36 system to form a node 2.