# US 8,540,461 B2 · Circular pile head for underpinning a slab > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,461 B2 - Document ID: US8540461B2 - Status: Granted - Kind: B2 - Application number: 13/257,448 - Filed: 2009-10-01 - Published: 2012-01-19 - Granted: 2013-09-24 - Earliest claimed: 2009-03-20 - Applicants: Chin Chai Ong - Inventors: Chin Chai Ong - Web page: https://patentgrep.com/patent/US8540461B2 ## CPC - E02D 35/00: Straightening, lifting, or lowering of foundation structures or of constructions erected on foundations {(foundations for sinking territories with incorporated means for remedying settlement E02D27/34; lifting or moving buildings E04G23/06)} - E02D 5/60: Piles with protecting cases - E02D 11/00: Methods or apparatus {specially adapted} for both placing and removing sheet pile bulkheads, piles, or mould-pipes (features relating to placing only E02D7/00, to removing only E02D9/00 {; placing apparatus which without special provisions, can be operated to remove, e.g. vibrating drivers E02D7/00}) - E02D: FOUNDATIONS; EXCAVATIONS; EMBANKMENTS (specially adapted for hydraulic engineering E02B); UNDERGROUND OR UNDERWATER STRUCTURES {(tunnels, tunnelling, mining E21)} ## Abstract A circular pile head assembly that can facilitate the driving of the underpinning pile in a slab using a pile driving machine and locking-off the slab load to the underpinning pile is provided. A circular pile head assembly consists of the twin beam, the circular pile head and a section of an underpinning pile that is used in conjunction with a pile driving machine to drive, and lock-off the slab load to the underpinning pile. ## Claims ### Claim 1 A circular pile head assembly comprising: a twin beam lifting attachment having a pair of beams configured to be placed above a pre-bored hole in a slab, each beam having a first connector; a tubular pile head including a pair of partial-cylindrical segments, each segment having a bearing plate extending generally transverse therefrom for engagement with an underside of the slab, each segment further having a second connector configured to connect with the first connector to connect the twin beam lifting attachment to the pile head; a rectangular pile configured to be driven between the partial-cylindrical segments of the pile head, wherein a gap is defined between the pile and the partial-cylindrical segments for receiving a poured cement; a pile head plate fixedly connecting the pair of partial-cylindrical segments, the pile head plate having a pair of curved edges corresponding to the partial-cylindrical segments and a pair of straight edges corresponding to a rectangular pile to frame the gap between the straight edges of the pile and curved edges of the pile head; and a pile driver for driving a rectangular pile into the pile head and toward a surface below the slab for reinforcement; wherein lifting of the twin beam lifting attachment causes the tubular pile head to lift and raise the slab to a raised position and cement inserted into the gap secures the slab in the raised position. ### Claim 2 (depends on 1) The circular pile head assembly of claim 1, wherein each of the partial-cylindrical segments of the pile head consists of two arcs no more than 120 degrees cut out from a circular pipe to form body sections of the circular pile head. ### Claim 3 (depends on 2) The circular pile head assembly of claim 2, wherein each partial-cylindrical segment of the pile head can be snugly inserted, unobstructed, through the pre-bored hole in the slab. ### Claim 4 (depends on 3) The circular pile head assembly of claim 3, wherein the bearing plates have two edges trimmed off so that it can be inserted unobstructed into the pre-bored through hole in the slab. ### Claim 5 (depends on 4) The circular pile head assembly of claim 4, wherein the trimmed off edges may be of any angle to maximize the bearing area contact with the pre-bored through hole in the slab. ### Claim 6 (depends on 4) The circular pile head assembly of claim 4, wherein each of the bearing plates is strengthened by a plurality of wedges attached to a lower outer body section of the corresponding segment to bear against a soffit in the slab. ### Claim 7 (depends on 1) The circular pile head assembly of claim 1, wherein the shape of each beam can be C-channel, I-Beam or any tabular structure strong enough to withstand the flexure. ### Claim 8 (depends on 1) The circular pile head assembly of claim 1, wherein each beam includes an upper hook and a lower through hole, the circular pile head assembly further comprising a first lock pin inserted through the upper hooks, and a second lock pin inserted through the lower through holes. ### Claim 9 (depends on 1) The circular pile head assembly of claim 1, wherein the pile head plate is welded to the partial-cylindrical segments of the pile head and further strengthened by a plurality of wedges. ### Claim 10 (depends on 4) The circular pile head assembly of claim 4, wherein each of the trimmed edges is aligned with an edge of the underpinning pile. ### Claim 11 (depends on 9) The circular pile head assembly of claim 9, wherein the gaps are filled with cement grout to further strengthen the underpinning pile to the slab.