Cutting Tool Adapter and Method of Underpinning Structures Using Cutting Tool Adapter for Soil Mixing

Abstract

A cutting tool adapter for creating an underpinning structure and method of creating the underpinning structure are provided. In some examples, the cutting tool adapter may connect a cutting tool to a working machine arm to enable the cutting tool to cut and dislodge soil below an existing foundation or structure. As the soil is cut and dislodged, it is mechanical mixed with an additive, such as a cementitious material, via the cutting tool. The mixed soil and additive may then harden in the area below the existing structure or foundation to create an underpinning structure to provide additional support for the existing structure or foundation.

Claims

1. A method of underpinning an existing structure, comprising: creating an approach pit in an area adjacent to soil below the existing structure; inserting a mechanical cutting tool into the approach pit, the mechanical cutting tool including at least a rotatable drum and plurality of cutting blades attached thereto and inserting the mechanical cutting tool into the approach pit including rotating the mechanical cutting tool about a first axis of rotation located between the mechanical cutting tool and an arm of a working machine; cutting and dislodging soil below the existing structure by rotating the drum and plurality of cutting blades relative to a remaining portion of the cutting tool and about a second axis of rotation different from the first axis of rotation; introducing an additive to the soil below the existing structure; using the mechanical cutting tool, mixing the soil and the additive in an area below the existing structure; and allowing the mixed soil and additive to harden forming an underpinning structure below the existing structure.

2. The method of underpinning an existing structure of claim 1, wherein the cutting tool is one of: a transverse cutting tool and an axial cutting tool.

3. The method of underpinning an existing structure of claim 1, wherein introducing the additive is performed while the cutting and dislodging is performed.

4. The method of underpinning an existing structure of claim 1, wherein the additive is a cementitious material.

5. The method of underpinning an existing structure of claim 4, wherein the cementitious material is a cementitious slurry.

6. The method of underpinning an existing structure of claim 4, wherein the cementitious material is a dry powder.

7. The method of underpinning an existing structure of claim 1, wherein the additive is a chemical grout.

8. The method of underpinning an existing structure of claim 1, further including, prior to allowing the mixed soil and additive to harden forming an underpinning structure below the existing structure, inserting one or more reinforcing members into the mixed soil and additive.

9. The method of underpinning an existing structure of claim 1, wherein the underpinning structure created by the hardened soil and additive mixture is in contact with a bottom surface of the existing structure.

10. The method of underpinning an existing structure of claim 1, wherein the cutting tool is a transverse cutting tool and wherein the second axis of rotation is an axis of drum rotation transverse to an axis of the arm of the working machine.

11. The method of underpinning an existing structure of claim 1, wherein forming an underpinning structure below the existing structure includes forming a single, continuous underpinning structure extending from and in contact with a bottom surface of the existing structure to a depth below the existing structure.

12. The method of underpinning an existing structure of claim 11, wherein the single, continuous underpinning structure is formed using a single soil and additive mixing process.

13. A method of underpinning an existing structure, comprising: creating an approach pit in an area adjacent to soil below the existing structure with a mechanical cutting tool, the mechanical cutting tool including at least a drum and plurality of cutting blades attached thereto; rotating the mechanical cutting tool to a substantially horizontal position, rotating the mechanical cutting tool including rotating the drum and plurality of cutting blades; cutting and dislodging soil below the existing structure by rotating the drum and plurality of cutting blades relative to a remaining portion of the cutting tool; introducing an additive to the soil; using the mechanical cutting tool, mixing the soil and the additive in an area below the existing structure; and allowing the mixed soil and additive to harden forming an underpinning structure below the existing structure.

14. The method of underpinning an existing structure of claim 13, wherein introducing the additive to the soil is performed during creation of the approach pit.

15. The method of underpinning an existing structure of claim 13, wherein the cutting tool is one of: a transverse cutting tool and an axial cutting tool.

16. The method of underpinning an existing structure of claim 13, wherein introducing the additive is performed while the cutting and dislodging is performed.

17. The method of underpinning an existing structure of claim 13, wherein the additive is a cementitious material.

18. The method of underpinning an existing structure of claim 13, wherein the underpinning structure created by the hardened soil and additive mixture is in contact with a bottom surface of the existing structure.

19. The method of underpinning an existing structure claim 13, wherein the cutting tool is connected to an arm of a working machine and rotating the cutting tool includes rotating the cutting tool, including the drum and plurality of blades connected thereto, relative to the arm of the working machine.

20. The method of underpinning an existing structure of claim 13, wherein the cutting tool is a transverse cutting tool having an axis of drum rotation transverse to an axis of the arm of the working machine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGS. 1A-1D illustrate one example cutting tool adapter according to one or more aspects described herein.

[0018] FIGS. 2A-2I illustrate example excavation site and underpinning arrangements formed using the cutting tool adapter and other aspects described herein.

[0019] FIG. 3 is an exploded view of one example cutting tool adapter and associated working machine arm and cutting tool in accordance with one or more aspects described herein.

[0020] FIG. 4 is a flow chart illustrating one example method of creating an underpinning structure using the cutting tool adapter and other aspects described herein.

[0021] FIG. 5 is an exploded view of another example cutting tool adapter and associated working machine arm and cutting tool in accordance with one or more aspects described herein.

[0022] FIGS. 6A-6D illustrate another example cutting tool adapter according to one or more aspects described herein.

[0023] FIGS. 7A and 7B illustrate example additive addition line arrangements in accordance with one or more aspects described herein.

DETAILED DESCRIPTION

[0024] In the following description of the various embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration, various embodiments of the disclosure that may be practiced. It is to be understood that other embodiments may be utilized.

[0025] As discussed herein, aspects described are directed to a cutting tool adapter configured to connect a cutting tool to an arm of a working machine. The cutting tool adapter may enable use of one or more cutting tools to perform underpinning of an existing structure using, for example, soil-cement. Soil-cement may be used, in some examples, instead of concrete as it provides sufficient load bearing capacity, may be more cost effective, relies on more efficient methods of installation, and the like. For instance, while soil-cement may not have a same strength as concrete, it has a sufficient strength to transfer loads associated with an existing structure or foundation to the soil or rock of the bearing stratum. Soil-cement also has sufficient strength to be durable (e.g., soil-cement will not readily spall, abrade, fall apart on exposure to chemicals, or the like). For instance, soil-cement is strong enough to resist any other loads that may need to be applied, such as a horizontal stabilizing force. In some examples, concrete may have a typical unconfined compressive strength of 3,000 psi. Soil alone may have a typical unconfined compressive strength of 30 psi. Soil-cement may have a typical unconfined compressive strength between 50 and 2,000 psi, thereby providing sufficient strength to support any desired or necessary loads.

[0026] These and various other aspects will be described more fully herein.

[0027] For example, FIGS. 1A-1D illustrate one example cutting tool adapter. As shown, the cutting tool adapter includes a base plate 104. The base plate may include a first adapter arm 102a and a second adapter arm 102b. In some examples, the first adapter arm 102a and second adapter arm 102b may be formed as part of the base plate (e.g., as a single piece). In other examples, the first adapter arm 102a and second adapter arm 102b may be connected to the base plate 104 using one or more fasteners, welding operations, or the like. In some examples, when connected to the base plate 104, the first adapter arm 102a and second adapter arm 102b may extend parallel or substantially parallel to each other. Each adapter arm 102a, 102b may have two opposite generally planar surfaces connected by two side surfaces. In some examples, the side surfaces may be arcuate surfaces, as shown in the figures.

[0028] The first adapter arm 102a may include an upper aperture 112a and a lower aperture 114a. The second adapter arm 102b may include an upper aperture 112b and a lower aperture 114b. The upper apertures 112a and 112b, and the lower apertures 114a and 114b may be generally aligned when the first adapter arm 102a and second adapter arm 102b are connected to the base plate 104.

[0029] The cutting tool adapter 100 may further include a first connecting pin 110a and a second connecting pin 110b. The first connecting pin 110a may connect the first adapter arm 102a to the second adapter arm 102b by extending through upper aperture 112a and upper aperture 112b. The cutting tool adapter 100 may further include a second connecting pin 110b. The second connecting pin 110b may connect first adapter arm 102a to second adapter arm 102b by extending through lower aperture 114a and lower aperture 114b. In some examples, as shown in FIG. 1B, the first connecting pin 110a and the second connecting pin 110b may form an angle. FIG. 1B illustrates the angle as being X. In some examples, X may be between 50 and 100 degrees. In other examples, X may be between 55 and 90 degrees. In some example arrangements, X may be a 60 degree angle. In some examples, an angle of 60 degrees may enable a hydraulic cylinder to rotate the attached cutting tool sufficiently to permit the cutting tool to extend upward, downward, and/or to contact the bottom surface of an existing structure, which, in some examples, is not achievable or is inefficient when using tools having other (e.g., smaller) angles.

[0030] Each connecting pin 110a, 110b may be secured using one or more fasteners. For instance, FIG. 1D is an exploded view of the cutting tool adapter 100 illustrating some example fasteners that may be used. For instance, the connecting pins 110a, 110b may be secured using fasteners 116, 118. In some examples, fasteners 116 may be any type of suitable screw. For example, fastener 116 may be a cylinder head cap screw. Fasteners 116 may extend through each connecting pin 110a, 110b via a flanged on an outer surface of each adapter arm 102a, 102b and surrounding each aperture 112a, 112b, 114a, 114b. The fastener 116 may be held in place using fasteners 118 which may be any suitable type of fastener. For example, fasteners 118 may be hex nuts.

[0031] In some examples, the first adapter arm 102a and second adapter arm 102b may further include a support fin to aid in securing the first adapter arm 102a and second adapter arm 102b to the base plate 104. For instance, a first support fin 106a may extend between a side surface of the first adapter arm 102a and the base plate 104. A second support fin 106b may extend between a side surface of second adapter arm 102b and the base plate 104. Each support fin 106a, 106b may aid in maintaining a position of each of the first adapter arm 102a and second adapter arm 102b.

[0032] In some examples, the first adapter arm 102a and second adapter arm 102b may further include a support element to aid in securing the first adapter arm 102a and second adapter arm 102b to the base plate 104 and to each other. For instance, support element 108 may extend between opposing side surfaces of first adapter arm 102a and second adapter arm 102b and may additionally be secured to base plate 104.

[0033] FIG. 1C is a section view of the cutting tool adapter taken along line A-A shown in FIG. 1B. FIG. 1C illustrates connecting pin 110a extending between first adapter arm 102a and second adapter arm 102b. FIG. 1C further illustrates support fins 106a and 106b.

[0034] The cutting tool adapter 100 may be connected to an arm of a working machine, such as an excavator or other earth moving piece of equipment, to enable a cutting tool (e.g. a transverse or axial cutter or mixing tool) to project horizontally, inclined upwards (e.g., with respect to a horizontal plane), or inclined downwards (e.g., with respect to a horizontal plane). In some examples, the cutting tool adapter 100 may be fastened or connected to the working machine arm at two pin locations (e.g., first connecting pin 110a and second connecting pin 110b). In some examples, one pin location (e.g., first connecting pin 110a) may be fixed and serve as an axis of rotation. Another, different pin location (e.g., second connecting pin 110b) may be connected to a hydraulic cylinder (e.g., a bucket cylinder). Accordingly, extension or retraction of the hydraulic cylinder may cause the adapter plate to rotate relative to the working machine (e.g., about the first connecting pin 110a) and may subsequently cause the cutting tool to rotate relative to the working machine (e.g., an arm of the working machine). Rotation of the cutting tool relative to the working machine may enable positioning of the cutting tool in various locations. A portion of the cutting tool itself may then rotate (e.g. the cutter drum or shaft) to cut and dislodge the earth from below the existing structure or foundation and, in some examples, to contact a bottom surface of the existing structure or foundation. In some examples, the cutting tool adapter may be rotated (e.g., with the cutting tool) by a rotating device attached to the arm of the working machine. In this example, the rotating device may operate independently of the hydraulic cylinder to rotate the cutting tool relative to the arm of the working machine. Rotation of the cutting tool thereby enables the cutting tool to cut and dislodge earth from below the existing structure or foundation and, in some examples, to contact a bottom surface of the existing structure or foundation.

[0035] The cutting tool adapter 100 may, in some examples, be between 5 inches and 72 inches in length (e.g., dimension L in FIG. 1B). In some arrangements, the cutting tool adapter 100 may be between 8 inches and 32 inches in length (e.g., dimension L in FIG. 1B). In still other examples, the cutting tool adapter 100 may be between 15 inches and 25 inches in length (e.g., dimension L in FIG. 1B). In some examples, this length may enable the cutting tool to extend a desired distance under the existing structure or foundation. The cutting tool adapter 100 may be formed of any suitable material including various metals, composites, or the like.

[0036] FIGS. 2A-2I illustrate one example process for using a cutting tool adapter, such as cutting tool adapter 100 in FIGS. 1A-1D, in conjunction with a working machine for use in underpinning an existing structure or foundation. For instance, FIG. 2A illustrates one example excavation site for underpinning an existing structure or foundation. The existing structure 202 includes a foundation formed of concrete or other suitable materials. As shown in FIG. 2A, in some examples, an approach pit 206 may be dug along the existing foundation 202. In some examples, the approach pit 206 may be dug prior to starting the soil mixing process. In other examples, the soil cement mixing process may begin at the ground surface 204 and the approach pit may be created during the soil cement mixing process. The approach pit 206 may be dug to any suitable depth below the existing grade 204 of the work site. In some arrangements, the approach pit 206 may be a depth of between four (4) and six (6) feel below the existing grade 204 of the work site. This arrangement may enable access to portions of the work site below the existing foundation 202 of the structure. For instance, the approach pit 206 may enable a cutting tool, such as a cutting tool connected to a working machine via the cutting tool adapter, to access portions of the work site below the foundation 202 of the existing structure prior to starting the soil mixing process. Furthermore, as will be evident later in the process, the approach pit 206 may provide a space for excess soil-cement mixture to collect during the underpinning process.

[0037] FIG. 2B illustrates the excavation site including a cutting tool within the approach pit 206. In some examples, a working machine arm 208 may be used to remove soil located adjacent to and below the existing foundation 202. The working machine arm 208 may be connected to a cutting tool 210 (shown schematically) via a cutting tool adapter, such as adapter 100 in FIGS. 1A-1D, adapter 500 in FIG. 5, adapter 600 in FIGS. 6A-6D, or the like. Various types of cutting tools, such as axial cutting tools, transverse cutting tools, soil mixing tools, and the like, may be used without departing from the invention. For instance, a cutting tool with a singular cutter drum rotating about a generally vertical axis may be described as an axial cutting tool. The axis of rotation of an axial cutting tool may be within a plane established by the arm of the working machine. In another example, a cutting tool with two cutter drums mounted in spaced relation and rotating about a generally horizontal shared axis is described may be described as a transverse cutting tool. The axis of rotation of a transverse cutting tool may be generally transverse to a plane established by the arm of the working machine.

[0038] The cutting tool 210 is shown in FIG. 2B as substantially aligned with the working machine arm 208. This arrangement of the equipment may be at a start of an excavation process. The cutting tool 210 may be inserted into the approach pit 206 and the cutter drums or shafts may rotate to begin cutting and mixing soil.

[0039] The working machine may be used to advance the cutting tool 210 forward from the approach pit 206 (in arrangements in which an approach pit is dug before the soil cement mixing process, or, alternatively, downward and then forward from the ground surface 204) and under the existing foundation 202. The cutting tool 210 may then cut and dislodge and partially remove soil from an area located below the existing foundation 202 in preparation for underpinning the existing structure or foundation. The cutting tool 210 may be moved laterally (e.g. to the left and to the right) as it is advanced under the existing foundation 202, thereby cutting and dislodging soil within the extents of the underpinning area. The cutting tool 210 may also be moved upward and downward to enable thorough mixing of the soil cement.

[0040] As the cutting tool 210 advances under the existing foundation, cementitious material may be introduced to the area via additive addition line 212. In some examples the cementitious material may include a cement powder mixed with water that, when mixed with soil, may harden to form an underpinning structure. In some examples, the ratio of water to cement (by weight) may range from 0.7 to 2.0. In some examples, the cementitious material and water may be introduced as separate components to the area without using additive addition line 212, (e.g. via direct placement). Accordingly, as the cementitious material is introduced into the area below the existing foundation 202, it may be mechanically mixed with the soil via the rotating cutter drums or shafts of the cutting tool. The mechanically mixed soil and cementitious material may form a fluid soil-cement that fills the approach pit and the area below the existing foundation. The fluid soil-cement 214 may then harden to form the underpinning element to support the existing structure 202. In some examples, the soil-cement will contain between 200 and 1000 lbs of cement per cubic yard.

[0041] The addition of cementitious slurry via the additive addition line may be performed at a variety of delivery pressures and piping arrangements. In some examples, such as shown in FIG. 7B, the additive addition line 712 may terminate as an open-ended pipe or tube 714b through which low pressure cementitious slurry flows into the area of mixing. In such examples, the cementitious slurry may be pumped to the mixing area using line pressures typically ranging from 25-500 psi. In such examples, mechanical mixing is adequate to combine the soil and cementitious slurry to create soil-cement.

[0042] In contrast, in some examples (e.g. clay or clayey soils), mechanical mixing alone may not be sufficient to combine the soil and cementitious slurry in an efficient manner. In these examples, such as shown in FIG. 7A, the additive addition line 712 may terminate in one or more nozzles or restrictions 714a through which high pressure cementitious slurry is injected into the area of mixing. In such examples, line pressures typically ranging from 500 to 6,000 psi may be used to pump the cementitious slurry through the nozzles. The concentrated flow of slurry through one or more nozzles may be directed at or near the cutter drums to assist in the mixing of the soil and slurry. The concentrated flow of slurry may remove soil adhering to the cutter drums and it may also cut and mix the soil near the cutter drums, creating a fluid or semi-fluid soil-cement mixture.

[0043] Advantageously, the cutting tool 210 may be used to cut and dislodge soil to any desired depth and may be used to remove and/or mix soil from a bottom of an underpinning depth to a bottom surface of the existing structure or foundation 202. For instance, the cutting tool 210 may cut and dislodge soil adjacent or immediately adjacent to the bottom surface of the existing foundation 202 and may mix the soil with cementitious material in order to create soil-cement that will harden in contact with the existing structure 202. This may ensure continuous vertical support for the existing structure. In addition, this continuous support may be generated via a single soil-cement mixing process, rather than requiring additional steps to insert or otherwise add a portion of an underpinning to span a gap between an underpinning element and the bottom of the existing foundation 202 that may be generated when other, conventional underpinning arrangements or processes are used.

[0044] Advantageously, the cutting tool 210 may also be used to cut and dislodge soil across any desired width measured parallel to the existing structure or foundation and to any desired horizontal distance back, measured perpendicular from the front of the existing structure or foundation. The cutting tool may mix the soil with cementitious material to create soil-cement that will harden in contact with the existing structure 202. This may provide an underpinning element composed of substantially planar surfaces that may be preferable to the cylindrical elements generated when other conventional methods are used to generate soil-cement elements fully or partially beneath existing structures or foundations.

[0045] As shown in FIG. 2C, the cutting tool 210 may rotate relative to the working machine arm 208. For instance, as shown in FIG. 2C, the hydraulic cylinder 215 may be extended or retracted to rotate the cutting tool 210 about one of the connecting pins in the cutting tool adapter 100. Accordingly, the cutting tool 210 may extend forward of the working machine arm 208 to extend below or beneath the existing structure 202. The cutting tool 210 may extend below a generally horizontal plane, as shown in FIG. 2C (e.g., the cutting tool 210 may be positioned below or at a lower elevation than a bottom of the working machine arm or point of rotation of the cutting tool adapter 100) or may extend in a substantially horizontal position as shown in FIG. 2D (e.g., along a horizontal plane as shown by line 211 in FIG. 2D). In some examples, the cutting tool adapter 100 connecting the cutting tool 210 to the working machine arm 208 may be used to angle the cutting tool 210 to an upward position (e.g., the cutting tool 210 may be positioned above or at a higher elevation than a bottom or distal end of the working machine arm 208 or point of rotation of the cutting tool adapter 100) as shown in FIG. 2E. The working machine arm 208 may continue to advance the cutting tool 210 further under the existing structure 202 and deeper below the existing structure by positioning the cutting tool at various angles to remove and mix soil and cementitious material to generate soil-cement. The working machine arm 208 may also move laterally throughout the process, thereby moving the cutting tool laterally as it advances further and deeper below the existing structure and removes and mixes soil.

[0046] FIG. 2F illustrates a finished underpinning support structure or element formed of hardened soil-cement and created using the method described herein. As shown in FIG. 2F, the underpinning extends to a depth, D below the existing structure 202 and is in contact with the bottom surface of the existing foundation 202. In some examples, depth D may be between two (2) and 20 feet. As shown in FIG. 2G, the underpinning extends a horizontal distance, H, back from the front of the existing foundation. In some examples, horizontal distance H may be between two (2) and five (5) feet. In some examples, the width of the underpinning element measured parallel to the front surface of the existing foundation may be between 2 and 8 ft. In some examples, the top surface of the soil-cement underpinning material may extend alongside and above the bottom of the existing foundation 202 to provide a finished surface below the existing grade 204.

[0047] FIG. 2G illustrates one example optional arrangement in which an additional reinforcing member 220 is positioned below the existing structure 202. In some arrangements, as desired, one or more reinforcing members 220 may be inserted into the fluid soil-cement (e.g., before hardening occurs) to provide additional load bearing capacity to the soil-cement element and/or the existing structure. In some arrangements, the reinforcing members may be extended below the bottom of the soil-cement element 214 to develop additional load carrying capacity. FIG. 2G includes portion 222 of reinforcing member 220 that extends below the bottom of the soil-cement element 214.

[0048] FIG. 2H illustrates another example arrangement in which a partitioning device 250 may be inserted into the fluid soil-cement (e.g., before hardening). For example, a partitioning device 250 may be inserted into the fluid soil-cement (e.g., below the existing structure or foundation, along an outside edge of an existing structure or foundation, or the like) to exclude portions of the soil-cement mixture that extend beyond (e.g., in a generally horizontal direction) the portion of the existing structure or foundation requiring support.

[0049] FIG. 2I illustrates another example optional arrangement in which an additional support member 230 is positioned below the existing structure 202. In some arrangements, as desired, one or more support members may be installed through the hardened soil-cement to provide horizontal and/or vertical support to the soil-cement element.

[0050] FIG. 3 illustrates an exploded view of the working machine arm 208, cutting tool adapter 100 and cutting tool 210. As discussed herein, the working machine arm 208 may be connected to a first pin location (e.g., first connecting pin 110a in FIGS. 1A-1D) and may be fixed to provide a point of rotation about which the cutting tool adapter 100 and cutting tool 210 may rotate. The hydraulic cylinder 215 may connect to another pin location (e.g., second connecting pin 110b) and extension or retraction of the hydraulic cylinder 215 may cause the cutting tool adapter 100 and cutting tool 210 to rotate about pin 110b and relative to the working machine arm 208.

[0051] The cutting tool adapter 100 may then be connected to the cutting tool 210 using, for example, fasteners such as screws, bolts, or the like. The additive addition line 212 may be used to introduce cementitious material to the soil in order to fluidize the soil to enable the cutting tool 210 to advance through the soil and mix the soil with cementitious or other material via cutting tool 210 to generate soil-cement.

[0052] FIG. 4 illustrates one example method of creating a soil-cement underpinning structure or element using the cutting tool adapter in accordance with one or more aspects described herein. At step 400, a cutting tool adapter, such as cutting tool adapter 100 shown in FIGS. 1A-1D, cutting tool adapter 500 in FIG. 5, cutting tool adapter 600 in FIGS. 6A-6D, may be used to connect a cutting tool to a working machine. The working machine may be any suitable type of machine having sufficient weight, stability, horsepower, hydraulic oil flow and pressure, arm length, and/or arm range of motion to operate the attached cutting tool 210. In some examples, an additional machine may be used along with the working machine to provide additional hydraulic oil flow to the cutting tool. In some examples, the cutting tool, such as cutting tool 210, may be a transverse or axial cutting tool configured with rotating drums or shafts to enable the eroding and mixing of soil from an area. Various other types of cutting and mixing tools may be used without departing from the invention.

[0053] The cutting tool 210 may be connected to the working machine arm 208 via the cutting tool adapter, such as adapters 100, 500, 600. In some examples, one or more fasteners, such as screws, bolts, and the like, may be used to connect the cutting tool to the cutting tool adapter and/or to connect the cutting tool adapter to the working machine arm.

[0054] At step 402, an approach pit may be created. For instance, the cutting tool connected to the working machine (or, in some examples, an alternate cutting tool and/or an alternate machine) may be used to remove a portion of soil adjacent (e.g., immediately next to) and below the existing structure or foundation such that an empty approach pit is created. In some examples, the approach pit may be between two (2) and six (6) feet wide, and may extend between one (1) and 10 feet deep below the bottom of the structure or foundation. In some examples, it may not be possible to excavate an empty approach pit. In such cases, as discussed above, the cutting tool may be used to cut and dislodge the soil in the approach pit area while cementitious grout is introduced to the area, thereby creating a fluid or semi-fluid soil-cement mixture within the approach pit (e.g., without first digging the approach pit).

[0055] At step 404, the cutting tool 210 may be inserted into the approach pit (or remain there in examples in which the cutting tool is used to create the approach pit). In some examples, inserting the cutting tool into the approach pit may include positioning the cutting tool such that the cutting tool is positioned in a horizontal or substantially horizontal position. Accordingly, in some examples, the cutting tool may be advanced in a general horizontal position and then may be adjusted as desired (e.g., upward or downward). In other examples, the cutting tool may be positioned above or below a horizontal plane and then may be adjusted to move the cutting tool to a substantially horizontal position or to another desired position.

[0056] At step 406, rotation of the cutter drums or shafts of the cutting tool or other cutting operation may be initiated. For instance, power may be introduced to the cutting tool to initiate rotation of the cutter drums or shafts and, accordingly, cutting and dislodging of soil from an area adjacent the approach pit and below the existing foundation or structure.

[0057] At step 408, cementitious grout or other material may be introduced into an area in which the cutting tool is operating. In some examples, steps 408 and 406 may be performed simultaneously such that a cutting tool rotates to cut and dislodge soil while the cementitious material is introduced to mix the soil and cementitious material.

[0058] As discussed herein, cementitious material may be introduced to the area as a slurry via a line or tube (e.g., additive addition line 212). In some examples, the slurry may be pumped at low pressures through an open-ended pipe or tube. In other examples, the slurry may be pumped at high pressures through one or more nozzles. As discussed above, FIGS. 7A and 7B illustrate example arrangements. The cementitious slurry may also be introduced via direct placement into the mixing area. Any suitable cementitious material may be used. For example, Portland cement, slag cement, fly ash, and/or silica fume may be used. Mechanical mixing of the soil and cementitious material may be performed in order to create a soil-cement material. In some examples, the cementitious material may be a cementitious slurry. In other examples, the cementitious material may be a dry powder. In some examples, water may be added to the area to facilitate mixing of the soil-cement and to achieve the desired fluid properties of the soil-cement mixture. In some examples, chemical grout may be used in lieu of cementitious material. For example, chemical grouts such as sodium silicate, acrylates, urethane, epoxy and polyester may be used in lieu of cementitious material.

[0059] In some examples, air-entraining admixtures may be added to the cement grout to provide freeze-thaw resistance to the soil-cement element. Additionally or alternatively, non-cementitious slurry, such as bentonite slurry and/or polymer slurry, may be mixed with the soil and the fluid soil-slurry mixture is later displaced using tremie concrete or cement grout, thereby forming an underpinning element of suitable strength and size.

[0060] In some arrangements, rapid hardening cement, chemical additives and/or thermal energy may be incorporated into the soil-cement element to achieve high early strength gain and enable the soil-cement element to support foundation loads sooner than is possible with, for example, Type 1 cement.

[0061] At step 410, the cutting tool may be advanced forward (e.g., further under the existing structure or foundation), upward (e.g., toward a bottom of the existing structure or foundation) and/or downward (e.g., to a further depth below the existing structure or foundation). As the cutting tool is advanced, additional additive (e.g., cementitious material) is introduced and mixed with the soil to generate a fluid soil-cement which may allow the cutting tool to advance and penetrate more freely or easily. Further, the fluid soil-cement may exert hydrostatic pressure against the sides and/or bottom of the excavation area (e.g., area below the existing structure 202 in which excavation and mixing is occurring) which may aid in stabilizing and supporting adjacent soil from collapsing into the excavation area.

[0062] In some examples, the cutting tool may be used to remove and/or mix soil up to a portion of soil in contact with the existing structure or foundation (e.g., to a bottom surface of the existing structure or foundation). Accordingly, the soil-cement mixture creating by mechanically mixing soil and additive (e.g., cementitious material) may be formed up to and in contact with the bottom surface of the existing structure or foundation. In other examples, a gap may be left between the soil-cement material created and the bottom surface of the existing structure or foundation. In those examples, the gap may be subsequently filled with a material or member suitable for transferring the foundation load to the soil-cement element created. Some examples of suitable material for filling the gap may include moist mixtures of sand and cement (drypack), mortar, concrete, or soil-cement, although other materials may be used without departing from the invention. Some examples of suitable members may include steel plates, shims, or structural shapes.

[0063] At step 412, the cutting tool may be removed from the underpinned area and approach pit. In some examples, removal of the cutting tool may include inserting one or more additional devices, members, or the like.

[0064] For example, a partitioning device, such as partitioning device 250 in FIG. 2H, may be inserted into the fluid soil-cement (e.g., below the existing structure or foundation, along an outside edge of an existing structure or foundation, or the like) to exclude portions of the soil-cement mixture that extend beyond (e.g., in a generally horizontal direction) the portion of the existing structure or foundation requiring support.

[0065] In still other examples, one or more reinforcing members, such as reinforcing member 220 in FIG. 2G, may be inserted into the fluid soil-cement to provide additional load carrying capacity to the soil-cement element or structure. In some examples, the reinforcing members, or portions thereof, such as portion 222 in FIG. 2G, may be extended below the bottom of the soil-cement element to develop additional load carrying capacity.

[0066] At step 414, the fluid soil-cement created during the mixing process may be allowed to harden. The hardened soil-cement element may then create a durable underpinning for the existing structure that provides sufficient load support (e.g., use of concrete is not necessary).

[0067] In some arrangements, as discussed above, one or more support members, such as support member 230 in FIG. 21, may be installed through the hardened soil-cement to provide additional horizontal and/or vertical support.

[0068] At step 416, the process may be repeated as desired. For instance, additional soil-cement underpinning elements may be created under the same or other existing structures or foundations. In some examples, after the soil-cement element has hardened (e.g., is installed beneath the existing structure or foundation), the soil-cement underpinning element may itself be underpinned using the process described herein, or one or more other types of underpinning processes.

[0069] FIG. 5 illustrates one example exploded view of an alternate cutting tool adapter 500. Similar to other arrangements discussed herein, the arrangement of FIG. 5 includes a working machine arm 508, an additive additional line 512, and a cutting tool 510. The cutting tool adapter 500 includes a first portion 501 and a second portion 503. In some examples, the first portion 501 and the second portion 503 may be formed separately and joined together using fasteners such as screws, bolts, and the like. In other examples, first portion 501 and second portion 503 may be formed as a single piece.

[0070] The first portion 501 of the cutting tool adapter 500 may be generally triangular in shape. In some examples, the first portion 501 may be an equilateral triangle having three equal sides. The first portion 501 may be formed of steel, iron, or other material suitable for connecting the cutting tool 510 to the second portion 503 of the cutting tool adapter 500.

[0071] The second portion 503 of the cutting tool adapter may include two pin locations 505a and 505b. Similar to arrangements discussed above, the working machine arm 508 may connect to a first pin location 505a via a connecting pin (e.g., similar to the first connecting pin arrangement described with respect to FIGS. 1A-1D). The hydraulic cylinder 515 may connect to the second pin location 505b. While the first connecting pin 505a may be fixed and may provide a point about which the cutting tool 510 may rotate, the second connecting pin 505b may be connected to the hydraulic cylinder 515 and, as the hydraulic cylinder is extended or retracted, may cause the cutting tool 510 to rotate relative to the working machine arm 508, similar to rotation arrangements described above.

[0072] The second portion 503 may be formed of steel, iron, or other material suitable for connecting the first portion 501 to the working machine arm 508. Accordingly, when the working machine arm 508 is connected to the second portion 503 which is connected to the first portion 501 and the cutting tool 510, the cutting tool can be rotated relative to the working machine arm 508 to enable cutting at various angles, similar to the arrangements described above.

[0073] FIGS. 6A-6D illustrate another example cutting tool adapter arrangement. As shown in FIGS. 6A-6D, the cutting tool adapter includes a base plate 604. The base plate may include a first adapter arm 602a and a second adapter arm 602b. In some examples, the first adapter arm 602a and second adapter arm 602b may be formed as part of the base plate (e.g., as a single piece). In other examples, the first adapter arm 602a and second adapter arm 602b may be connected to the base plate 604 using one or more fasteners, welding operations, or the like. In some examples, when connected to the base plate 604, the first adapter arm 602a and second adapter arm 602b may extend parallel or substantially parallel to each other. Each adapter arm 602a, 602b may have two opposite generally planar surfaces connected by two side surfaces.

[0074] The first adapter arm 602a may include an upper aperture 612a and a lower aperture 614a. The second adapter arm 602b may include an upper aperture 612b and a lower aperture 614b. The upper apertures 612a and 612b, and the lower apertures 614a and 614b may be generally aligned when the first adapter arm 602a and second adapter arm 602b are connected to the base plate 604.

[0075] The cutting tool adapter 600 may further include a first connecting pin 610a and a second connecting pin 610b. The first connecting pin 610a may connect the first adapter arm 602a to the second adapter arm 602b by extending through upper aperture 612a and upper aperture 612b. The cutting tool adapter 600 may further include a second connecting pin 610b. The second connecting pin 610b may connect first adapter arm 602a to second adapter arm 602b by extending through lower aperture 614a and lower aperture 614b. In some examples, as shown in FIG. 6B, the first connecting pin 610a and the second connecting pin 610b may form an angle. FIG. 6B illustrates the angle as being X. In some examples, X may be between 50 and 100 degrees. In other examples, X may be between 55 and 90 degrees. In some example arrangements, X may be a 60 degree angle. In some examples, an angle of 60 degrees may enable a hydraulic cylinder to rotate the attached cutting tool sufficiently to permit the cutting tool to extend upward, downward, and/or to contact the bottom surface of an existing structure, which might not be possible with some (e.g., smaller) angles.

[0076] Each connecting pin 610a, 610b may be secured using one or more fasteners. For instance, FIG. 6D is an exploded view of the cutting tool adapter 600 illustrating some example fasteners that may be used. For instance, the connecting pins 610a, 610b may be secured using fasteners 616, 618. In some examples, fasteners 616 may be any type of suitable screw. For example, fastener 616 may be a cylinder head cap screw. Fasteners 616 may extend through each connecting pin 610a, 610b via a flange on an outer surface of each adapter arm 602a, 602b and surrounding each aperture 612a, 612b, 614a, 614b. The fastener 616 may be held in place using fasteners 618 which may be any suitable type of fastener. For example, fasteners 618 may be hex nuts.

[0077] In some examples, the first adapter arm 602a and second adapter arm 602b may further include a support fin to aid in securing the first adapter arm 602a and second adapter arm 602b to the base plate 604. For instance, a first support fin 606a may be generally rectangular and may extend between a side surface of the first adapter arm 602a and the base plate 604. A second support fin 606b may be generally rectangular and may extend between a side surface of second adapter arm 602b and the base plate 604. Each support fin 606a, 606b may aid in maintaining a position of each of the first adapter arm 602a and second adapter arm 602b.

[0078] In some examples, the first adapter arm 602a and second adapter arm 602b may further include a support element to aid in securing the first adapter arm 602a and second adapter arm 602b to the base plate 604 and to each other. For instance, support element 608 may extend between opposing side surfaces of first adapter arm 602a and second adapter arm 602b and may additionally be secured to base plate 604. Support element 608 may be generally rectangular in some arrangements.

[0079] FIG. 6C is a section view of the cutting tool adapter taken along line B-B shown in FIG. 6B. FIG. 6C illustrates connecting pin 610a extending between first adapter arm 602a and second adapter arm 602b. FIG. 6C further illustrates support fins 606a and 606b.

[0080] Similar to cutting tool adapters 100 and 500, cutting tool adapter 600 may be connected to an arm of a working machine, such as an excavator or other earth moving piece of equipment, to enable a cutting tool (e.g. a transverse or axial cutter or mixing tool) to project horizontally, inclined upwards (e.g., with respect to a horizontal plane), or inclined downwards (e.g., with respect to a horizontal plane). In some examples, the cutting tool adapter 600 may be fastened or connected to the working machine arm at two pin locations (e.g., first connecting pin 610a and second connecting pin 610b). In some examples, one pin location (e.g., first connecting pin 610a) may be fixed and serve as an axis of rotation. Another, different pin location (e.g., second connecting pin 610b) may be connected to a hydraulic cylinder (e.g., a bucket cylinder). Accordingly, extension or retraction of the hydraulic cylinder may cause the adapter plate to rotate relative to the working machine (e.g., about the first connecting pin 610a) and may subsequently cause the cutting tool to rotate relative to the working machine (e.g., an arm of the working machine). Rotation of the cutting tool relative to the working machine may enable positioning of the cutting tool in various locations. A portion of the cutting tool itself may then rotate (e.g. the cutter drum or shaft) to cut and dislodge the earth from below the existing structure or foundation and, in some examples, to contact a bottom surface of the existing structure or foundation. Rotation of the cutting tool thereby enables the cutting tool to cut and dislodge earth from below the existing structure or foundation and, in some examples, to contact a bottom surface of the existing structure or foundation.

[0081] The cutting tool adapter 600 may, in some examples, be between 5 inches and 72 inches in length (e.g., dimension L in FIG. 1B). In some arrangements, the cutting tool adapter 600 may be between 8 inches and 32 inches in length (e.g., dimension L in FIG. 1B). In still other examples, the cutting tool adapter 600 may be between 15 inches and 25 inches in length (e.g., dimension L in FIG. 1B). In some examples, this length may enable the cutting tool to extend a desired distance under the existing structure or foundation. The cutting tool adapter 600 may be formed of any suitable material including various metals, composites, or the like.

[0082] As discussed herein, the various cutting tool arrangements described enable use of soil-cement mixing to create an underpinning structure having sufficient load bearing strength, while meeting or contacting, in at least some examples, a bottom surface of an existing structure under which the underpinning is being created.

[0083] Although the invention has been defined using the appended claims, these claims are illustrative in that the invention may be intended to include the elements and steps described herein in any combination or sub combination. Accordingly, there are any number of alternative combinations for defining the invention, which incorporate one or more elements from the specification, including the description, claims, and drawings, in various combinations or sub combinations. It will be apparent to those skilled in the relevant technology, in light of the present specification, that alternate combinations of aspects of the invention, either alone or in combination with one or more elements or steps defined herein, may be utilized as modifications or alterations of the invention or as part of the invention. It may be intended that the written description of the invention contained herein covers all such modifications and alterations.