On-site construction method for foundation piles

Abstract

To easily construct a foundation pile even in a narrow site without using a large-sized pile driver having a long leader, with reduced noise and vibration, and enable on-site construction of a foundation pile having a required diameter; and to provide a foundation pile which has high pull out strength or has high quality.SOLUTION: An on-site construction method for a foundation pile uses a launcher which connects a vertical type propulsion machine and a subsequent steel pipe to a foundation pile installation scheduled ground surface and starts the machine and steel pipe in a vertical direction and allows the machine and steel pipe to be recovered to the ground. The method feeds excavated waste soil taken in from a hydraulic jack device and an excavator to the ground with a soil discharge pipe, kneads the sent excavated waste soil with a solidification material, pressure-feeds the kneaded material as a solidified body into a pipe of the soil discharge pipe and fills a drilled hole with the solidification material, and lifts the material to the ground side while stirring the material with a cutter part of the excavator, and recovers the material.SELECTED DRAWING: Figure 19

Description

[Technical field]

[0001] When constructing a concrete structure or a large, heavy concrete building such as an apartment building or a building on the ground, a large number of foundation piles with a required diameter and a specified length are driven into the ground at the construction site as foundation work to support the heavy structure or large building. This invention relates to a technology for constructing these foundation piles by excavating vertical holes using a horizontal hole boring machine used in underground burial pipe construction, reusing the generated soil, adding a solidifying material to form improved soil, and mixing and filling the drilled holes. [Background technology]

[0002] As shown in Patent Documents 1 and 2, conventional foundation pile driving work involves installing a PC impact machine or pile driver equipped with a long vertical leader of over 10 m on the site, and using a PC pile driving method or pre-boring method to drive long foundation piles from above ground into the ground while applying impact vibrations until they reach the supporting layer, thereby constructing the foundation piles. Also, when constructing cast-in-place piles, one method involves digging with a boring machine using a large crawler crane, filling the hole with a bentonite solution or the like, and then replacing it with concrete from below using a tremie pipe.

[0003] This conventional foundation pile construction method requires the safe installation of large, tall PC hammers, pile drivers, drilling machines, etc., and requires a large installation space. In addition, there is a risk that the PC hammers and pile drivers will tip over due to earthquakes or wind, destroying surrounding buildings, and they also generate large vibrations and noise at the construction site.

[0004] In addition, with the conventional foundation pile installation method, it was difficult to change the pile diameter or length on-site in response to the properties of the ground below or changes in those properties. Also, the amount of excavated soil particles discharged to the ground during ground excavation work was large, and the subsequent disposal of the excavated soil particles was costly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-211225 A [Patent Document 2] Japanese Patent Application Publication No. 08-144673 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a new construction method for foundation piles which solves the following conventional problems and has the following advantages A to E. (i) The pile diameter and length can be changed on-site in response to ground conditions and changes, enabling the construction of appropriate foundation piles. (b) The excavated soil particles discharged to the ground are re-introduced as an improved soil by adding solidification material on-site, making effective use of the soil, reducing the amount of waste soil and reducing the labor required for post-discharge soil processing. C: To prevent large vibrations and noise from occurring during the foundation pile driving work. 2) To significantly reduce the cost of transporting and using large PC impact machines, pile drivers, and drilling machines with long upward leaders that are necessary for conventional foundation pile work, to the site, as well as the labor and workload required for crane work to drive and hoist piles and steel materials on site. E: The tunneling machines and other equipment used will be able to be transported in and out through narrow public roads, thereby realizing labor savings. F: Eliminate the need for long secondary concrete products, steel materials, etc., and significantly reduce the work of transporting them. [Means for solving the problem]

[0007] The configuration of the present invention that solves such problems is as follows: 1) A method for constructing foundation piles on site, in which a closed tunneling machine is driven vertically into the ground at the site where foundation piles for a building are to be installed, to excavate holes of a specified diameter and depth, and then the excavated soil and solidification material are mixed and filled into the holes to construct solidified foundation piles at the positions of the holes, The tunneling machine has a partition wall at the lower end of a vertical cylindrical outer shell, an excavation cutter section below the partition wall, and further has a soil discharge port for taking in excavated soil and sand, and a rotating device for rotating the cutter section and an opening / closing valve for opening and closing the soil discharged from the soil discharge port on the way upward inside the shell. tube and a plurality of steel pipes are prepared, the diameter of the outer shell of the tunneling machine being the same as the diameter of the foundation pile to be constructed, the rear end edge of the tunneling machine and the edges of the steel pipes connected as the lining body being the same diameter, and the steel pipes can be freely connected to each other with flanges, and the soil discharge pipes are arranged so as to be passed through the inside of the steel pipes and sent to the ground. Furthermore, a launching platform is provided on the ground surface at the site where the tunneling machine is to be driven, which can support the tunneling machine in a vertical direction, can connect the required number of stages of steel pipes above the tunneling machine, and can remove the uppermost stage of steel pipe by releasing the flanges from the stages of steel pipes connected to the tunneling machine above the tunneling machine. A hydraulic jack device is provided which presses the flange-connected topmost steel pipe vertically to generate a vertical thrust force on the tunneling machine and the steel pipe, and which presses upward the topmost steel pipe connected to the tunneling machine with a flange to lift the tunneling machine and the connected steel pipe to a launch pad on the ground; an improved body manufacturing device which mixes a prescribed ratio of solidifying material with the waste soil transported from the tunneling machine via the soil discharge pipe and stored in a stock tank, or with the waste soil generated at another site and transported, to produce an improved body; and an improved body pumping device which pumps the improved body thus produced into the inside of the soil discharge pipe exposed above ground. an excavation process in which, during excavation, the tunneling machine is held facing downward on the launching platform, a predetermined number of steel pipes are flange-connected above the tunneling machine, and the tunneling machine is operated while applying a vertical pressing force to the topmost steel pipe with the hydraulic jack device, and while the tunneling machine is excavating vertically, the required number of steel pipes are added upward on the launching platform, thereby lining the ground to the required depth required for the foundation piles; An improved body manufacturing process in which the excavation process uses the excavated soil sent to the ground from the excavation pipe of the tunneling machine or the excavated soil from another site to mix a solidification material at a predetermined ratio on the ground and produce an improved body with an improved body manufacturing device; and a process in which the improved body produced is pressure-fed into the excavation pipe exposed on the ground by an improved body pressure-feeding device, and the improved body is pressed through the excavation pipe from the cutter bulkhead at the tip of the tunneling machine underground while the steel pipe connected to the flange is fed by the hydraulic jack. Hold The improvement body filling and mixing process involves lifting the tunneling machine and the steel pipe above it to the ground level of the starting platform with a hydraulic jack, separating the flange-connected steel pipes, and recovering the tunneling machine to the ground. The improvement body that was stirred while the tunneling machine was being recovered upward solidifies and forms a wall of the drilled hole with a specified outer diameter and a specified depth that reaches the supporting ground. Attached This is a construction method for on-site foundation piles, which consists of a solidification process in which the concrete foundation piles are attached to the supporting ground and then solidified to complete the on-site concrete foundation piles supported by the supporting ground. 2) A method for constructing foundation piles on site as described in 1) above, in which an annular inner flange is provided that protrudes from the rear edge of the outer shell of the tunneling machine to the inside of the outer shell as a flange connecting the rear edge of the outer shell of the tunneling machine and the lower end edge of the steel pipe serving as a lining immediately above it, and an annular inner flange is provided that protrudes from the respective edges of the upper and lower ends of the steel pipe to the inside of the pipe, and the tunneling machine and the inner flanges that overlap above and below the opposing edges of the steel pipe above them, which are arranged in series in the same vertical direction, are connected to each other detachably with bolts and nuts at the launch pad. 3) The launch pad is on the site ground. FirmlyThe launch platform has a frame structure that holds the tunneling machine and the steel pipe so that the tunneling machine and the steel pipe connected thereto are in the same vertical direction as the pile center position of the foundation pile to be constructed, and the launch platform has a frame structure that holds the tunneling machine and the steel pipe so that the tunneling machine and the steel pipe can move up and down in the same vertical direction. The hydraulic jack device has a structure in which a push wheel that can press the pipe end of the uppermost steel pipe is attached to the launch platform so that it can move up and down in the same vertical direction, and a plurality of double-pull hydraulic jacks are provided between the push wheel and the base of the launch platform that is installed on the ground, and the tips of the cylinder rods of the plurality of hydraulic jacks are attached to the push wheel, and the cylinder body side of the hydraulic jacks is attached to the base of the launch platform. a hydraulic jack that pulls both ways is operated so that the cylinder rod of the hydraulic jack that pulls both ways extends upwards, by connecting the push ring and the steel pipe of the topmost stage to the hydraulic jack, and a fixing nut is provided on the inner flange of the upper edge of the uppermost steel pipe, and the upper part of a suspension bolt that can be screwed onto the fixing nut can be engaged with the pushing ring; when the tunneling machine and steel pipe are pushed down, the pushing ring abuts against the upper edge of the uppermost steel pipe to operate the double-pull hydraulic jack in a downward direction, and when the tunneling machine and steel pipe are raised, the lower threaded part of the suspension bolt is screwed into the fixing nut on the inner flange of the uppermost steel pipe to connect the pushing ring and the steel pipe of the topmost stage, and the double-pull hydraulic jack is operated so as to extend upwards, thereby lifting the tunneling machine and the steel pipe connected thereto upwards; 4) The above 3) Description In the on-site construction method of foundation piles, On the ground of the site, a vacuum pump that sucks the discharged soil to the ground side through the soil discharge pipe, a soil discharge storage tank that temporarily stores the discharged soil sent to the ground by the vacuum pump, a solidification material hopper that stores the solidification material, an improved body manufacturing device that produces the improved body by kneading the discharged soil in the soil discharge storage tank and the solidification material in the solidification material hopper at a predetermined ratio, an improved body pressure feeding device and its piping that feeds the improved body produced by the improved body manufacturing device into the soil discharge pipe of the tunneling machine, a launching platform that can vertically arrange the tunneling machine and multiple steel pipes relative to the ground above the foundation piles to be produced at the site, and that can vertically hold a propellant having opposing flanges detachably connected by bolts and can also move the propellant downward toward the ground or upward toward the ground, and a hydraulic jack device attached to the launching platform that can push down the top steel pipe of the propellant supported by the launching platform or lift it upward toward the ground side, First, a tunneling machine with an outer diameter approximately the same as the pile mouth of the foundation pile to be driven in the same vertical direction is placed on the starting platform, and a number of steel pipes with an outer diameter approximately the same as the outer diameter are placed above the tunneling machine. The vertical tunneling machine and the steel pipes above them are connected to each other with flanges, and then the hydraulic jack device attached to the starting platform is operated to apply a downward force to the uppermost push wheel by the hydraulic jack device to the tunneling machine and the multiple connected steel pipes, while the rotation of the tunneling machine is started. motionBy operating the device, the tunneling machine excavates the ground in a vertical direction with its cutter section, takes in the excavated soil from the soil discharge port of the bulkhead, and temporarily stores the discharged soil in the soil discharge tank via the soil discharge pipe and the vacuum pump on the ground. Also, when the tunneling machine excavates the steel pipe connected to it downward by the length of several pipes, the necessary number of steel pipes are added to the upper end lip of the topmost steel pipe inserted as a lining in the ground of the launching platform so that they are on the same vertical line as the steel pipe pressed into the ground on the launching platform, and the steel pipes are connected to each other with flanges, and then the topmost pipe end of the added steel pipe is lifted up by the hydraulic jack device. The hydraulic jack device is used to press the same vertical line downward with the push wheel while simultaneously operating the tunneling machine to excavate. When the tunneling machine has excavated to a predetermined depth where the ground strength is high, the operation of the hydraulic jack device and the tunneling machine is stopped. The discharged soil from the discharged soil storage tank and the solidification material in the solidification material hopper are mixed in a predetermined ratio in an improved body manufacturing device to produce an improved body. The improved body thus mixed is then pumped into the soil discharge pipe exposed above ground by the improved body pumping device, and the improved body is ejected from the soil discharge port at the lower end while the tunneling machine is operated and stirred with its cutter section. The uppermost steel pipe on the starting platform is then pumped by the hydraulic jack device. Upwards By lifting the tunnel, the improvement material is ejected from the tunnel discharge port toward the face, filling and mixing the inside of the drilled hole while the tunnel and steel pipe connected to the flange are Up When the multiple steel pipes and the tunneling machine are moved to the launching platform on the ground, the flange connections are released at the launching platform, the steel pipes and the tunneling machine are removed from the launching platform, and the tunneling machine and the upper steel pipes are returned to the ground for reuse. At the same time, the improvement material filled and mixed in the drilled hole is solidified, and becomes a foundation pile that has the advantages of both a high-strength support pile with a long excavation depth that reaches the supporting layer with the diameter of the tunneling machine, and a friction pile that is dense with the surrounding ground, and further, Rooted in The above-mentioned can be used to construct a solid foundation pile. 3) Note On-site construction method for foundation piles 5) The soil used for the improvement body is excavated by the tunneling machine and sent to the ground through the soil discharge pipe, eliminating the need to transport the soil to a treatment plant. ~4) On-site construction method of foundation piles as described in any one of the following is located. Effect of the Invention

[0008] According to the present invention, a tunnel boring machine used in tunnel jacking method is used to drill holes for foundation piles in the ground at the site, and multiple steel pipes that follow it above are flange-connected to a launching platform on the ground, and the boring machine is operated while being placed vertically from the launching platform and pushed down by a hydraulic cylinder, and a hole is excavated in the ground with the cutter at the bottom of the boring machine. Therefore, the method of the present invention makes it possible to carry out construction in narrow spaces, and vibrations and noises that are sensed on the ground are greatly reduced. The soil discharged from the face is taken into the soil discharge pipe through the soil discharge valve inside the boring machine from the soil discharge port in the bulkhead at the bottom of the boring machine, and is transported through the steel pipe to the soil discharge container tank on the ground side.

[0009] Furthermore, whether the tunneling machine has reached a layer with high supporting strength can be accurately confirmed by the rotational load on the cutter, or by measuring devices such as an excavation depth gauge, or by the length of the tunneling machine and the number of steel pipes driven in, and the tunneling machine can be made to reach the supporting layer to the required depth by adding the required number of steel pipes to the tunneling machine with flanges. In this invention, hydraulic jacks are used for the downward pushing and lifting of the tunneling machine and steel pipes, so no noise or vibration is generated. Also, since no expensive machinery is used, it is easy to work in narrow areas.

[0010] When the tunneling machine reaches the supporting layer at a specified depth, the tunneling machine and steel pipe are stopped, and the discharged soil and sand sent to the ground side are mixed with the solidification material in the solidification material hopper installed on the ground side in a specified ratio in a kneading device. The improved soil produced by the mixing is pumped by the pressure pump into the inside of the soil discharge pipe exposed above ground. If the discharged soil generated during excavation is used, it is mixed with the solidification material on the ground and returned to the drilling hole, so most of the discharged soil volume is reused and reduced.

[0011] The pressure-fed improvement body passes through the soil discharge pipe and is discharged to the face from the soil discharge port in the partition at the lower end of the tunneling machine, allowing the face space to be pressurized and filled with the improvement body.

[0012] Moreover, when the tunneling machine is operated in this state and the rotating blade of the cutter at the bottom rotates, this cutter remixes and stirs the improvement mass filled in the face, and the injection pressure at the time of insertion allows it to thoroughly fill in any irregularities or cracks in the pile hole wall. While rotating this rotating blade of the cutter, the hydraulic jack device on the ground slowly lifts the steel pipe connected with the flange and the entire tunneling machine below it above ground. In this way, the concrete strength of the hardened foundation pile is high, ensuring a high quality and also allowing for accurate construction of the pile diameter and depth.

[0013] As the tunneling machine rises, the improvement mass from the soil discharge port is gradually ejected from above while being stirred by the cutter section, filling the pile hole evenly, and the stirring force and injection pressure of the improvement mass allow it to penetrate well into the hole wall. The tunneling machine and the steel pipe above it are all lifted by a hydraulic jack device on a launch pad on the ground. With this method, the tunneling machine and the steel pipe above it are advanced into the ground and lifted to the launch pad using the digging force of the tunneling machine and the propulsion and lifting force of the hydraulic jack device, so no impact or vibration noise is generated and there is almost no pollution from these.

[0014] This process allows the improvement body to be thoroughly mixed with the excavated soil and sand, and to be solidified while being thoroughly filled in the pile hole under pressure and agitation. When the tunneling machine and steel pipe are raised to a starting platform on the ground, the flange connection between the tunneling machine and the upper steel pipe is released and separated, or they are moved to the starting platform for the next foundation pile driving position without being separated.

[0015] When the improvement body is filled into the drilled hole and solidified, the solidified body in the center of the drilled space and the improvement body on the periphery of the pile hole adhere to the cracks and unevenness in the drilled hole wall due to the filling pressure and stirring by the cutter, and the solidified outer periphery solidified body spreads out like branches to become an integrated foundation pile.A foundation pile with a pile diameter the same as the diameter of the tunneling machine's shell and which is strongly integrated with the surrounding ground is created.

[0016] The on-site foundation pile construction method of the present invention provides the following advantages (1) to (13). (1) This is a construction technique that reduces the size of all construction machinery used, while still achieving the same high strength structures and quality as larger machinery. (2) Equipment can be brought in and out even on narrow public roads, and compact size can be achieved. (3) This construction method produces very little noise and vibration. (4) Piles made of steel or concrete prefabricated products are not used. (5) The weight of the tunneling machine itself (outer diameter φ1000mm, the tunneling machine tip weighs about 2.5t, and with an outer diameter of φ800mm it weighs about 2t) means that a mobile crane (10T lifting) is required to hoist the tunneling machine vertically once to set it up, but after that a vehicle such as a 4T truck (lifting truck) can be used to hoist the steel pipe, which makes it possible to reduce the use of construction machinery. (6) It is possible to freely change the drilling diameter (by replacing the tunneling machine) to ensure the bearing capacity for the weight of the building structure above and to deal with changes in the ground, so it is possible to respond flexibly to changes in the ground at the site. This is also an issue or concern that has been a problem with conventional foundation piles, and this construction method is highly adaptable to changes in the ground, the pile length to the supporting layer, and the pile cross-sectional area. (7) When the tunneling machine is pulled up, the improvement body is filled into the tunnel face, which strengthens the adhesion between the hole wall and the surrounding ground and increases the surrounding friction force (utilizing the advantages of both support piles and friction piles). (8) The excavated soil and sand are temporarily stored in a storage tank on the ground surface, and then later mixed and stirred with a cement-based material (solidification material) using a small mixer to convert it into an improved body with high plastic fluidity. This improved body is then refilled into the ground as pile material to construct improved piles. This construction method significantly reduces the amount of soil and soil that is ultimately disposed of, making it a construction technology that greatly reduces the environmental burden. (9) When the tunneling machine performs preliminary excavation while boring a hole in the ground, a reusable flange-fastened steel pipe is used for the following pipe body, and while filling the improvement body into the lowest tunneling machine face, the steel pipe and the tunneling machine are simultaneously pulled up to the ground by the amount of pressure filling to form a pile. The tunneling machine and all of the steel pipes can be recovered to the ground, and this is a cost-reducing construction method that can be reused for the next construction work. (10) The soil discharge system during excavation uses the tunneling machine soil discharge valve (air + rubber valve) used when constructing a horizontal pipeline inside the vertical tunneling machine's subsequent body pipe, and pulls the discharged soil up to the ground surface with a normal suction soil discharge device (vacuum force generator). In this case, since the steel pipe is unmanned, it is necessary to adjust the amount of air supplied, so the air supply steel pipe and soil discharge pipe are installed in parallel inside the steel pipe. In addition, an openable and closable valve is installed on the ground surface to adjust the amount of air supplied. (11) A cement-based solidification material is added to the waste soil generated during excavation (a mixture of natural soil and muddy water from the face). In this case, a mixing and stirring device is used to form a fluid improved mass, which is then reverse-injected into the drainage valve of the tunneling machine using a pressure pump to solidify the face. At this time, the cutter part of the tunneling machine is rotated to further mix the material, allowing the construction of highly uniform piles. (12) In the method of the present invention, the shape and dimensions of the excavated cross section and the reinjection cross section are clearly defined by drilling a hole with a tunneling machine and following steel pipes, etc., and the quality of the improved soil to be filled can be controlled by using test pieces each time. (13) Because a vertical tunneling machine is used, tunneling is carried out with the face pressurized, which means that the impact on the surrounding ground (loosening of the ground, etc.) is very small, and damage and impact to adjacent houses, etc. can be kept to a minimum. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a plan view showing the on-site setting state of each device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing an improved body manufacturing apparatus and an improved body pumping device of the embodiment. [Diagram 3] FIG. 3 is a perspective view showing the structure of the launch pad of the embodiment. [Figure 4] FIG. 4 is a front view of the launch pad of the embodiment. [Diagram 5] FIG. 5 is a side view of the launch pad of the embodiment. [Figure 6] FIG. 6 is a front view showing the hydraulic jack device of the embodiment. [Figure 7] FIG. 7 is a side view of the hydraulic jack apparatus according to the embodiment. [Figure 8]FIG. 8 is a front view showing the state in which three stages of steel pipes are connected with flanges on the starting platform of the embodiment. [Figure 9] FIG. 9 is a front view showing the state in which the lowest steel pipe of the launch pad of the embodiment has been embedded in the ground. [Figure 10] FIG. 10 is a plan view showing a pressure ring used in the embodiment. [Figure 11] FIG. 11 is a front view showing the guide rail of the starting platform of the embodiment. [Figure 12] FIG. 12 is a plan view taken along the line A in FIG. [Figure 13] FIG. 13 is a plan view taken along the line B in FIG. [Figure 14] FIG. 14 is an explanatory diagram of the internal structure of the tunneling machine of the embodiment. [Figure 15] FIG. 15 is an explanatory diagram showing the tunneling machine of the embodiment and the steel pipe above it being lifted from the launch pad. [Figure 16] FIG. 16 is an explanatory diagram showing the connected state of the inner flange that connects the steel pipes of the embodiment. [Figure 17] FIG. 17 is an explanatory diagram showing a structure for connecting a press ring and a steel pipe in the embodiment. [Figure 18] FIG. 18 is an explanatory diagram showing the construction process of the on-site foundation pile construction method of the embodiment. [Figure 19] FIG. 19 is an explanatory diagram showing the construction process of the on-site foundation pile construction method of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The tunneling machine of the present invention can be the same as that used in the jacking method for tunnel construction. EXAMPLES

[0019] The present invention will be described with reference to the embodiments shown in FIGS.

[0020] (Explanation of symbols in the embodiment) In the figure, G indicates the on-site construction method for foundation piles of the embodiment. 1 is a launching platform installed on the ground of the planned foundation pile, 10 is a ground frame that installs the launching platform on the ground, 11 is a vertical frame fixed to the ground frame, 12 is a horizontal frame that connects multiple vertical frames, 13 is an anchor member driven into the ground to anchor the ground frame to the ground, 14 is a cylindrical guide installed in the center of the ground frame for vertically entering the ground with the tunneling machine 3 and steel pipe 4, 15 is a jack to prevent the guide from sinking, and 16 is a guide for the up and down movement of the tunneling machine 3 and steel pipe 4 attached to the upper horizontal frame 12. Reference numeral 17 denotes a disk-shaped push wheel which transmits propulsion and lifting force to the steel pipe, 171 denotes a guide protrusion which engages with the guide rail 16 which brakes the up and down movement of the push wheel, 2 denotes a hydraulic jack device attached to the starting platform 1, 20 denotes multiple hydraulic jacks which are provided for pulling only and which make up the hydraulic jack device, 21 denotes the cylinder rod of the hydraulic jack, 22 denotes the cylinder body of the hydraulic jack, 220 denotes a link section which connects the tip of the cylinder rod 21 to the push wheel 17, and the cylinder body 22 is connected to the ground frame.23 is a suspension bolt attached to the push wheel side connecting the push wheel 17 and the top steel pipe, 24 is a fixing nut provided on the inner flange of the steel pipe that screws onto the lower end of the suspension bolt, 3 is a tunneling machine, 30 is the outer shell of the tunneling machine, 31 is an inner flange provided at the mouth edge at the upper end of the outer shell, 32 is a plurality of bolt holes provided in the flange, 33 is a partition wall at the lower end of the tunneling machine 3, 34 is a cutter section using a rotating blade that revolves around its axis and is provided on the outside of the center of the partition wall, 341 is the rotating shaft of the cutter section, and 342 is a shaft provided within the outer shell 30 above the partition wall 33. 3 is a rotary device for the cutter section 34, 35 is an earth discharge port provided in the center of the bulkhead, 36 is an earth discharge pipe connected to the earth discharge port, 37 is a rubber valve provided midway through the earth discharge pipe 36 and an earth discharge valve for opening and closing using air, 38 is an air supply steel pipe that takes in naturally aspirated air from the ground, 39 is an inner flange provided at the rear edge of the outer shell 30, 391 is a bolt hole provided in the inner flange 31 of the outer shell 30, 392 is a connecting bolt that connects the bolt hole to the bolt hole 42 of the inner flange 41 at the lower end of the steel pipe 4, 4 is a steel pipe with the same diameter as the outer shell 30, 41 is The steel pipe 4 has inner flanges on the upper and lower end edges, 42 has bolt holes on the flanges, 43 has connecting bolts connecting the bolt holes 42 on the inner flanges 41 on the upper and lower edges of the steel pipe 4, 50 has a vacuum pump that is connected to a discharge pipe arranged on the ground at the site and sucks up the discharged soil sent to the discharge pipe 36 by negative pressure, 51 has a discharged soil storage tank that stores the discharged soil on the ground after being sent to the ground through the discharge pipe, 52 has a solidification material hopper that stores the solidification material, and 53 has a screw that mixes the discharged soil from the discharged soil storage tank and the solidification material stored in the solidification material hopper in a predetermined ratio. The improved body is produced by mixing in a kneading machine in an improved body manufacturing device, 54 is an improved body pressure pump that pressure-feeds the improved body produced by the improved body manufacturing device into the soil discharge pipe 36 placed on the ground of the excavator via improved body injection piping 540, 55 is a crawler crane that grabs the launch pad 1 with the tip of the crane arm and moves the launch pad 1, 56 is an air tank, 57 is an air compressor, 59 is a hydraulic unit that outputs hydraulic pressure, 60 is an additive plant that stores other additives, and 61 is an additive pump that outputs additives from the additive plant.

[0021] (Construction process / work procedure) The work will be explained below according to the construction drawings in Figures 18 and 19. 1: A small pit is excavated at the pile position on the ground surface, and a guide 14, which is the pit entrance hardware (entrance), and a grounding frame 10 for the launch pad 1 are installed (see Figures 5 and 18). 2: Install a vertical launch platform 1 on top of the ground frame 10 at the entrance (see Figs. 3 to 5 and 18). 3: Fix the tunneling machine 3 and the upper steel pipe 4 inside the launch pad 1 (see Figures 5, 6, 7, 8, 9, and 18). 4: An excavation additive plant 60 (mud plant), waste soil storage tank 51, etc. are installed outside the mine. 5: Using the remote control panel, the hydraulic jack device 2 in the vertical launch platform 1 is used to rotate the rotary blade of the cutter unit 34 of the tunneling machine 3 while performing excavation work downward (see Figs. 5 to 9 and 18). 6: At the same time, the hydraulic jack (pull jack) 20 is used to push the tunneling machine 3 into the ground (the tunneling speed is approximately 2 cm / min to 10 cm / min) (see Figures 5 to 9, 18). 7: After the tunneling machine 3 is inserted into the ground, a steel pipe (temporarily about 80 cm to 100 cm long) is connected to the top of the tunneling machine 3 (repeat Figures 6 to 9, see Figure 18). 8: Once the pipe connection work is completed, re-excavation will be carried out (see Figures 6-9 and 18). 9: Once the excavation for the length of the No. 1 steel pipe is completed, change the setup and connect the No. 2 steel pipe (see Figures 6-9, 18, and 19). 10: Repeat the process of adding steel pipes (see Figures 6-9, 18, and 19) 11: After the excavation is completed down to the solid supporting ground SR, the waste soil stored in the waste soil storage tank 51 installed on the ground surface is mixed and mixed with the improved soil manufacturing device 53, which mixes and kneads the solidification material in the solidification material hopper 52, such as cement, to create a fluidized improved soil (see Figures 1, 2, and 19). 12: The improved body is pumped from the ground surface to the tunneling face by the improvement body pressure delivery pump 54, and the excavator 3's soil discharge pipe 36 is reused as a transport pipe to pump the improved body, filling it into the drilled hole (see Figure 19). 13: Depending on the lifting speed of the hydraulic jack device 2 of the tunneling machine 3, the improvement body is continuously pressurized and filled into the hole wall by the improvement body pressure delivery pump 54 (see Figure 19). 14: As soon as each steel pipe has been filled, it is pulled up by the hydraulic jack device 2, and the steel pipes 4 protruding from the launch pad 1 on the ground surface are removed one by one, forming a continuous cast-in-place pile from the bottom of the excavation (see Figure 19). 15: Repeat steps 11 to 13 above to pull the rear of the tunneling machine 3 up to the launch pad 1 on the ground surface (see Figure 19). 16: After the tunneling machine 3 is removed, the vertical launch pad 1 is dismantled and removed. 17: Finally, the tunnel head hardware installed on the surface is removed and one unreinforced cast-in-place pile foundation is completed.

[0022] In this way, construction is possible at the site where the foundation piles are to be constructed as long as a low launch platform and hydraulic jack device can be installed, so construction can be carried out easily and quickly even in a small site. It is safe and produces little noise and vibration, resulting in less pollution. [Industrial Applicability]

[0023] In this invention, multiple foundation piles can be constructed on site in parallel at the same time using multiple launch platforms and hydraulic jack devices, which makes the work easier and also makes it easy to change the pile diameter. [Explanation of symbols]

[0024] G Example of on-site construction method for foundation piles SR support ground 1 Launch pad 10 Ground Frame 11 Vertical Frame 12 Horizontal Frame 13 Anchor members 14 Guide 15 Anti-subsidence jack 16 Guide rail 17 Push Ring 171 Guide protrusion 2 Hydraulic jack device 20 Hydraulic jack for pulling only 21 Cylinder rod 22 Cylinder body 220 Link section 23 Hanging bolt 24 Fixing nut 3 digging machine 30 Outer shell 31 Inner flange 32 Bolt holes 33 Bulkhead 34 Cutter section 341 Rotational Axis 342 Rotating device 35 Soil discharge port 36 Earth discharge pipe 37 Soil discharge valve 38 Air supply steel pipe 39 Inner flange 391 Bolt hole 392 Connecting bolt 4 Steel pipe 41 Inner flange 42 Bolt holes 43 Connecting bolt 50 Vacuum Pump 51 Soil discharge storage tank 52 Solidification material hopper 53 Improved body manufacturing equipment 54 Improved body pressure pump 540 Improved body injection piping 55 Crawler crane 56 Air Tank 57 Air Compressor 59 Hydraulic Unit 60 Additive Plant 61 Additive pump

Claims

1. A method for constructing foundation piles on site, in which a closed tunneling machine is driven vertically into the ground at the site to drive foundation piles for a building, to excavate a hole of a specified diameter and depth, and then the excavated soil and solidification material are mixed and filled into the hole to construct a solidified foundation pile at the drilled hole position, The tunneling machine has a partition wall at the bottom end of a vertical cylindrical outer shell, and has an excavation cutter section below the partition wall, and further has an earth discharge port for taking in excavated earth and sand, and inside the outer shell above the partition wall has a rotating device for rotating the cutter section and an earth discharge pipe equipped with an opening and closing valve in the middle for sending the earth discharged from the earth discharge port upward, and the diameter of the outer shell of the tunneling machine is the same as the diameter of the foundation pile to be constructed, and a plurality of steel pipes are prepared which have the same diameter as the rear end edge of the tunneling machine and the edges of the steel pipes connected as the lining body and can be freely connected to each other detachably with flanges, and the earth discharge pipes are arranged so as to be passed through the inside of the steel pipes and sent to the ground, and further the tunneling machine can be supported vertically on the ground at the site where concrete is poured, and the required number of steel pipes can be connected above the tunneling machine, a launching platform capable of removing the topmost steel pipe by releasing the flanges from the multiple tiers of steel pipes connected to the tunneling machine with flanges; a hydraulic jack device mounted on the launching platform and capable of vertically pushing the topmost steel pipe connected to the tunneling machine with flanges to generate a vertical thrust on the tunneling machine and the steel pipes, and pushing the topmost steel pipe connected to the tunneling machine with flanges upward to lift the tunneling machine and the steel pipes connected thereto to the launching platform on the ground; an improved body manufacturing device that mixes a prescribed ratio of solidification material with the waste soil transported from the tunneling machine to the ground via the soil discharge pipe and stored in a stock tank or with the waste soil generated at another site and transported; and an improved body pumping device that pumps the improved body thus produced into the inside of the soil discharge pipe exposed on the ground. an excavation process in which, during excavation, the tunneling machine is held facing downward on the launching platform, a predetermined number of steel pipes are flange-connected above the tunneling machine, and the tunneling machine is operated while applying a vertical pressing force to the topmost steel pipe with the hydraulic jack device, and while the tunneling machine is excavating vertically, the required number of steel pipes are added upward on the launching platform, thereby lining the ground to the required depth required for the foundation piles; This on-site construction method for foundation piles comprises the steps of: an improved body manufacturing process in which the excavation process uses the waste soil discharged to the ground from the soil discharge pipe of the tunneling machine in the excavation process, and a predetermined ratio of solidification material is mixed on the ground with the improved body manufacturing device to produce an improved body; an improved body filling and mixing process in which the improved body prepared is pressure-fed into the tube of the soil discharge pipe exposed to the ground by an improved body pressure-feeding device, and the improved body is pressed through the soil discharge pipe into the drilled hole from the cutter partition at the tip of the tunneling machine underground while the steel pipe connected to the flange of the tunneling machine is lifted by the hydraulic jack while being stirred by the cutter part of the tunneling machine, thereby filling the drilled hole evenly with the improved body; a recovery process in which the tunneling machine and the steel pipe above it are lifted to the ground position of the launch pad by the hydraulic jack, the flange-connected steel pipe is separated, and the tunneling machine is recovered to the ground; and a solidification process in which the improved body stirred while the tunneling machine is recovered upward solidifies and adheres to the drilled hole wall with a predetermined outer diameter and a predetermined depth that reaches the supporting ground, completing a concrete on-site foundation pile supported by the supporting ground.

2. A method for on-site construction of foundation piles as described in claim 1, in which a flange connecting the rear edge of the outer shell of the tunneling machine and the lower end edge of the steel pipe serving as a lining directly above it and a flange connecting the edges of the upper and lower ends of the upper and lower steel pipes are provided with annular inner flanges that protrude from the rear edge of the outer shell of the tunneling machine to the inside of the shell, and annular inner flanges that protrude from the edges of the upper and lower ends of the steel pipe to the inside of the pipe, and the inner flanges that overlap above and below the opposing edges of the tunneling machine and the steel pipe above it, which are arranged in series in the same vertical direction, are connected to each other by bolts and nuts at the launch pad in a manner that allows them to be freely attached and detached.

3. The launch platform is fixed to the ground at the site and holds the tunneling machine and the steel pipe connected thereto so that they are in the same vertical direction as the center of the foundation pile to be constructed, and the launch platform has a frame structure that holds the tunneling machine and the steel pipe so that the tunneling machine and the steel pipe can move up and down in the same vertical direction. The hydraulic jack device is structured so that a push wheel that can press the end of the steel pipe that is the topmost level is attached to the launch platform so that it can move up and down in the same vertical direction, and a plurality of double-pull hydraulic jacks are provided between the push wheel and the base of the launch platform that is installed on the ground, and the tips of the cylinder rods of the plurality of hydraulic jacks are attached to the push wheel, and the cylinder body side of the hydraulic jacks is attached to the 3. A method for on-site construction of foundation piles as described in claim 2, wherein the structure is such that the hydraulic jack is attached to the base of a starting platform, a fixing nut is further provided on the inner flange of the upper edge of the topmost steel pipe, and the upper part of a suspension bolt that can be screwed into the fixing nut can be engaged with the pressure ring, and when the tunneling machine and steel pipe are pushed down, the pressure ring abuts against the upper edge of the topmost steel pipe to operate the double-pull hydraulic jack in a downward direction, and when the tunneling machine and steel pipe are lifted, the lower threaded portion of the suspension bolt screws into the fixing nut on the inner flange of the topmost steel pipe to connect the pressure ring and the topmost steel pipe, and the cylinder rod of the double-pull hydraulic jack is operated to extend upward, thereby lifting the tunneling machine and the steel pipe connected above it upward.

4. In the on-site construction method of foundation piles according to claim 3, On the ground of the site, a vacuum pump that sucks the discharged soil to the ground side through the soil discharge pipe, a soil discharge storage tank that temporarily stores the discharged soil sent to the ground by the vacuum pump, a solidification material hopper that stores the solidification material, an improved body manufacturing device that produces the improved body by kneading the discharged soil in the soil discharge storage tank and the solidification material in the solidification material hopper at a predetermined ratio, an improved body pressure feeding device and its piping that feeds the improved body produced by the improved body manufacturing device into the soil discharge pipe of the tunneling machine, a launching platform that can vertically arrange the tunneling machine and multiple steel pipes relative to the ground above the foundation piles to be produced at the site, and that can vertically hold a propellant having opposing flanges detachably connected by bolts and can also move the propellant downward toward the ground or upward toward the ground, and a hydraulic jack device attached to the launching platform that can push down the top steel pipe of the propellant supported by the launching platform or lift it upward toward the ground side, First, a tunneling machine with an outer diameter approximately the same as the pile mouth of the foundation pile to be driven in the same vertical direction is placed on the starting platform, and multiple steel pipes with an outer diameter approximately the same as the outer diameter are placed above it. The vertical tunneling machine and the steel pipe above it are connected to each other with flanges, and then the hydraulic jack device attached to the starting platform is operated to apply a downward force to the uppermost push wheel by the hydraulic jack device to the tunneling machine and the multiple connected steel pipes. The tunneling machine then excavates the ground in the vertical direction with its cutter section, and the excavated soil and sand are then poured into the partition wall. The soil is taken in from the soil discharge port and temporarily stored in the soil discharge storage tank via the soil discharge pipe and the vacuum pump on the ground. Also, when the tunneling machine excavates the steel pipe connected to it downward by the length of several pipes, the necessary number of steel pipes are added to the upper end lip of the topmost steel pipe inserted into the ground of the launch pad as a lining so that they are on the same vertical line as the steel pipe pressed into the ground on the launch pad, and the steel pipes are connected to each other with flanges. After that, the topmost pipe end of the steel pipe added by the hydraulic jack device is pressed downward on the same vertical line with the hydraulic jack device while the tunneling machine is excavated at the same time. The above-mentioned operation is repeated, and when the tunneling machine is excavated to a predetermined depth where the ground strength is high, the operation of the hydraulic jack device and the tunneling machine is stopped, and the discharged soil from the discharged soil storage tank and the solidification material in the solidification material hopper are mixed in a predetermined ratio in the improved body manufacturing device to produce an improved body, and the improved body thus mixed is pumped into the soil discharge pipe exposed above ground by the improved body pumping device, and the improved body is ejected from the soil discharge port at the lower end while the tunneling machine is operated to mix it with its cutter section, and the uppermost steel pipe on the starting platform is lifted upward by the hydraulic jack device, thereby the tunneling machine The improvement body is ejected from the discharge port towards the face, filling and mixing the inside of the drilled hole while the flange-connected tunneling machine and steel pipe are raised, and when the multiple steel pipes and the tunneling machine move to a launching platform on the ground, the flange connection at the launching platform is released, the steel pipes and the tunneling machine are removed from the launching platform, and the tunneling machine and the upper steel pipes are recovered to the ground and can be reused, and the improvement body filled and mixed in the drilled hole solidifies to become a foundation pile that has the advantages of both a high-strength support pile that reaches the supporting layer to the excavation depth with the diameter of the tunneling machine and a friction pile that is dense with the surrounding ground, and furthermore, a foundation pile with its base secured to the ground can be constructed.The on-site construction method for foundation piles according to claim 3.

5. A method for on-site construction of foundation piles as described in any one of claims 1 to 4, in which the excavated soil used for the improved body is excavated by the tunneling machine and sent to the ground through the excavation pipe, thereby eliminating the need to transport the excavated soil to a treatment plant.

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