JP2015110902A - Connection structure of backfilling agent supply pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure of backfilling agent supply pipes, capable of reducing a ground-change state after extracting an existing pile and backfilling, and capable of shortening a construction period.SOLUTION: The problem is solved by a connection structure of backfilling agent supply pipes as follows. The connection structure includes: first and second backfilling agent supply pipes 81 and 82 each formed with a connection part 80 having a semi-cylindrical part 83 and an inscribed cylindrical pipe projection part 86; and an engaging holding pipe 90 for restricting an engaging state in such a manner that both the connection parts 80 are made to face each other while deviating axes of the connection parts 80 from each other parallel, and one of both the semi-cylindrical parts 83 is fitted with the another side inscribed cylindrical pipe projection part 86 coaxially, then the engaging holding pipe 90 is externally fitted on outer peripheries of both the connection parts 80. There is provided a lock projection part 88 projecting from a part of an outer peripheral part of the first backfilling agent supply pipe connection part 81. There is also provided an introduction part 93 being a groove opened in the engaging holding pipe 90 and enabling going-in and going-out of the lock projection part 88 at one end of the pipe 90, and having a circumferential groove 94 extending in a circumferential direction of the engaging holding pipe 90 and a rotation preventive groove 96 extending in the axial direction.

Description

  The present invention is a pile unloading method having a pulling process of an existing pile remaining in the ground after dismantling the building, and a refilling process of filling a backfilling agent having fluidity after pulling the pile, And a connection structure of a backfilling agent supply pipe used in the pile unfilling method.

  Conventionally, when performing the work of pulling out the existing piles remaining in the ground after dismantling the building and backfilling, after performing the work of pulling out the piles, prepare a backfilling agent suitable for the land quality, The hole filling the hole made by pulling out the pile is filled with backfilling agent.

  However, since the surrounding earth and sand collapses and accumulates in the holes made by pulling out the piles, and the water and groundwater used for excavation are accumulated, even if a backfill agent is introduced from the upper part of the hole opening, Often does not reach the interior of the room. In this way, if uneven filling or voids of the backfilling agent are formed inside the backfilled hole, ground deformation will occur. If new pile driving is performed in a place where this ground deformation has occurred, the holes for drilling piles will be skewed or the piles to be pressed will be skewed. .

  Japanese Patent Application Laid-Open No. 2009-256999 (Patent Document 1) discloses a steel pipe pile pile removal method for preventing such ground deformation after pile removal.

  In the steel pipe pile drawing method described in Patent Document 1, first, a filler such as earth and sand packed in the inner periphery of an existing hollow pile in the ground, a spiral auger or a bladed drilling rod, etc. Using the agitating process to squeeze and squeeze through the middle drilling, the casing insertion process to excavate the outer peripheral surface of the pile by inserting a casing having a drilling function along the outer peripheral surface of the existing hollow pile, and discharged from the existing hollow pile A pile removing step of drawing an existing hollow pile from the ground while filling the pile filling hole opened in the ground.

  According to the steel pipe pile drawing method described in Patent Document 1, the existing hollow pile is pulled out while discharging the filler from the existing hollow pile, so that the pile weight is reduced by reducing the weight of the pile that has discharged the filler. In addition, it is possible to facilitate the filling process of the pile hole and to prevent ground deformation.

JP 2009-256999 A

  In the steel pipe pile drawing method described in Patent Document 1, when excavating using a casing along the outer peripheral surface of an existing hollow pile, a description of excavating while discharging jet water or mud from the tip of the casing ( For example, there is a paragraph number [0020]), and the filler in the existing hollow pile may have fluidity due to the jet water or mud water discharged.

  However, jet water or muddy water is discharged for the purpose of reducing excavation resistance due to rotation of the casing, and the fluidized filler is not prepared according to the surrounding ground properties. There is a high possibility that ground deformation has occurred. Therefore, when a pile is newly struck in a place where the ground deformation has occurred, problems such as the pile skewing occur.

  Moreover, the drawing method of the steel pipe pile described in patent document 1 can be limited and used for drawing of hollow piles, such as a steel pipe pile, and other PC pile (pressed concrete pile), PHC pile ( Pre-stressed high-strength concrete piles), BT piles (box-type piles), friction piles, etc., and ED piles (earth drill piles), reverse piles, pedestal piles, etc. There is a problem that.

  In addition, lubrication water and mud used at the time of excavation, ground water, collapsed earth and sand, and the like are collected at the bottom of the pile hole after the pile is extracted. In this state, even if a backfilling agent is introduced from the ground surface portion of the pile hole, it is solidified in a state of being mixed with water or earth and sand accumulated in the inside, so that there is a possibility of causing ground deformation. In order to fill the pile removal hole uniformly and reliably, the discharge port of the backfilling agent supply pipe that discharges the backfilling agent is made to reach the bottom of the pile removal hole, and the backfilling agent supply pipe It is necessary to discharge the backfilling agent from the discharge port and fill the water and the earth and sand accumulated in the backfilling hole while floating.

  In the case where the length of the existing pile is several meters or more, it is necessary to connect a plurality of backfilling agent supply pipes in order to make the discharge port of the backfilling agent reach the vicinity of the bottom of the pile removal hole. However, when the backfilling agent supply pipe is inserted into the excavation hole, the connecting part of the backfilling agent supply pipe may come into contact with the side wall of the excavation hole, and the connection between the backfilling agent supply pipes may be disconnected. is there. In particular, when the pile hole for inserting the backfill agent supply pipe is narrow or when the depth of the pile hole is deep, there is a high possibility that the connection between the backfill agent supply pipes is disconnected.

  24 to 27 show a conventional backfilling agent supply pipe connection structure and method.

  FIG. 24 is a view for explaining the structure of the conventional connecting portion 980 and the shape of the engagement holding tube 990 in the long first backfill agent supply tube 981 and the second backfill agent supply tube 982. FIG. 25 shows a state before the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982 are connected by the connection part 980 and the outer peripheral part of the connection part 980 is covered with the engagement holding pipe 990. FIG. In FIG. 26, the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982 are connected by a connecting portion 980, and a conventional engagement holding tube 990 is put on the outer peripheral portion of the connecting portion 980. It is a figure which shows the state fixed with the wire 992 so that the combined holding | maintenance pipe | tube 990 may not shift | deviate to the axial direction of the 2nd backfilling agent supply pipe | tube 982. FIG. In FIG. 27, a first backfilling agent supply pipe 981 and a second backfilling agent supply pipe 982 are connected by a connection part 980, and a conventional engagement holding pipe 990 is put on the outer periphery of the connection part 980. It is a figure which shows the state fixed with the gum tape 994 so that the combined holding pipe | tube 990 may not shift | deviate to the axial direction of the 2nd backfilling agent supply pipe | tube 982. FIG.

  As shown in FIG. 24, the end portion of the long first backfilling agent supply pipe 981 has a semicylindrical portion 983 formed by cutting it into a semicylindrical shape, and a tip inner cylindrical surface of the semicylindrical portion 983. A connecting portion 980 having an inscribed cylindrical tube protruding portion 986 attached with an engaging inscribed cylindrical tube 985 is formed. Similarly, at the end of the long second backfilling agent supply pipe 982, a semi-cylindrical portion 983 formed by cutting it into a semi-cylindrical shape, and an inner cylindrical surface of the tip of the semi-cylindrical portion 983 are used for engagement. A connecting portion 980 having an inscribed cylindrical tube protruding portion 986 attached with the inscribed cylindrical tube 985 is formed.

  When connecting the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982, first, the engagement holding pipe 990 is passed through the second backfilling agent supply pipe 982. Next, the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982 are displaced from each other in parallel, and the connecting portions 980 of the backfilling agent supply pipes face each other. At the same time as inserting the inscribed cylindrical tube protruding portion 986 of the connecting portion 980 of the second backfilling agent supply tube 982 into the semicylindrical portion 983 formed in the connecting portion 980 of the agent supplying tube 981, the second backfilling agent supply tube An inscribed cylindrical tube protruding portion of the connecting portion 980 of the first backfilling agent supply tube 981 is fitted inside the semi-cylindrical portion 983 formed in the connecting portion 980 of 982, and the first backfilling agent supply tube 981 and the second filling material 982 are inserted. The axis | shaft of the return agent supply pipe | tube 982 is made to correspond (refer FIG. 25).

  Thereafter, the engagement holding pipe 990 is moved to cover the outer periphery of the connection part 980 of the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982, thereby covering the first backfilling agent supply pipe 981. The engagement state with the second backfilling agent supply pipe 982 can be restricted.

  However, if the first backfilling agent supply pipe 981 and the second backfilling agent supply pipe 982 are inserted into the excavation hole with the engagement holding pipe 990 being put on the outer peripheral portion of the connection part 980, the engagement will occur. As the holding tube 990 comes into contact with the side wall of the excavation hole or the like, the engagement holding tube 990 is displaced upward and disengaged from the connection portion 980, and the first backfilling agent supply tube 981 and the second backfilling agent supply tube 982 The trouble that disconnects and disconnects frequently occurs.

  Therefore, conventionally, as shown in FIG. 26, in order to prevent the engagement holding tube 990 from being displaced upward and coming off the connection portion 980, the wire 992 is attached to the second backfilling agent above the engagement holding tube 990. It wound around the supply pipe | tube 982 so that the engagement holding | maintenance pipe | tube 990 and the 2nd backfilling agent supply pipe | tube 982 might be fixed using the gum tape 994 as shown in FIG.

  However, even if the engagement holding tube 990 is fixed as shown in FIGS. 26 and 27, the first backfilling agent supply tube 981 and the second backfilling agent supply tube 982 are inserted into the pile hole. At this time, the engagement holding tube 990 is displaced upward from the connection portion 980 due to the engagement holding tube 990 coming into contact with the side wall of the excavation hole, and the first backfilling agent supply tube 981 and the second backfilling. There was a problem that the connection with the agent supply pipe 982 was disconnected and separated.

  The present invention has been made in view of the above problems, and it is possible to reduce ground deformation after pulling out an existing pile remaining in the ground after dismantling the building and backfilling it, and to shorten the construction period. An object of the present invention is to provide a connecting structure for a pile unfilling method and a backfilling agent supply pipe used for the pile unfilling method.

  Further, the present invention provides a connecting structure for backfilling agent supply pipes that is difficult for the backfilling agent supply pipes to come off at their connecting portions even when the backfilling agent supply pipe is inserted into the pile hole. Yes.

  In order to solve the above-described problem, the pile refilling method according to the present invention includes an outer excavation step of excavating using an excavation casing along an outer peripheral surface of an existing pile, and an outer peripheral portion of the excavated existing pile. A backfill agent supply pipe disposing step of disposing a backfill agent supply pipe for supplying a backfill agent having fluidity; and supplying the backfill agent via the backfill agent supply pipe An existing pile pulling backfilling step of filling the pile punching hole with the backfilling agent by pulling up.

  According to this invention, by excavating the outer peripheral portion of the existing pile to be pulled out, disposing the backfilling agent supply pipe on the outer peripheral portion of the excavated existing pile, and pulling up the existing pile while supplying the backfilling agent, The backfilling agent can be directly filled in the pile punching hole without generating a void in the pile punching hole. Thereby, it becomes possible to more reliably fill the pile punching hole with the backfilling agent, and the ground deformation after the existing pile is pulled out and backfilled can be reduced. Moreover, in this invention, since the extraction operation | work of an existing pile and the filling operation | work of a backfill agent are performed simultaneously, the construction period of a pile extraction backfilling operation | work can be shortened.

  The pile unfilling method according to the present invention is the above-mentioned backfilling agent in the existing pile pulling backfilling process of the existing pile in the pile unfilling method together with the supply of the backfilling agent and the lifting of the existing pile. It is characterized by pulling up the supply pipe.

  According to this invention, when the backfilling agent supply pipe is pulled up together with the supply of the backfilling agent and the backfilling agent supply pipe is pulled up, when the backfilling agent that is quickly solidified is used or when the existing pile is long, it takes time to pull out. Even in such a case, the filling process of the backfilling agent can be performed more reliably, and the ground deformation after the backfilling can be reduced.

In order to solve the above-described problems, the connecting structure of the backfilling agent supply pipe according to the present invention includes a semi-cylindrical part formed by cutting an end part of a long pipe into a semi-cylindrical shape, and a tip inner cylindrical surface of the semi-cylindrical part First and second backfilling agent supply pipes each having a connecting portion having an inscribed cylindrical tube projection portion with an inscribed cylindrical tube attached thereto, and the first and second backfilling portions. Supply of the second backfilling agent into a semi-cylindrical portion formed in the first backfilling agent supply pipe connecting portion from a state in which the axes of the agent supply pipes are shifted in parallel and the respective connecting portions face each other. An inscribed cylinder of the first backfilling agent supply pipe connecting part is inserted into a semicylindrical part formed in the second backfilling agent supply pipe connecting part at the same time when the inscribed cylindrical pipe projecting part of the pipe connecting part is inserted. After inserting the pipe protrusion and aligning the axes of the first and second backfilling agent supply pipes, the first and second backfilling agent supply pipe connecting parts In the connection structure of refilling agent supply pipe and a engagement holding tube for restraining the engagement state of the first and second refilling agent feed pipe by covering the periphery,
A locking protrusion protruding from a part of the outer peripheral portion of the first backfilling agent supply pipe connecting portion, and a groove formed in the engagement holding pipe capable of passing the locking protrusion. A circumferential groove having an introduction portion that allows the lock protrusion to enter and exit at one end, and at least a groove opened in a circumferential direction of the engagement holding tube, and the engagement holding tube from the circumferential groove. And a rotation preventing groove that is opened in the axial direction.

  According to the present invention, the first and second backfilling agent supply pipes are connected at the connection portion so that the axes of the first and second backfilling agent supply pipes coincide with each other and the outer periphery of the connection portion is engaged. In the step of covering the joint holding tube, first, the lock convex portion is passed through the circumferential groove from the introduction portion of the circumferential groove and passed through the rotation preventing groove extending in the axial direction orthogonal to the circumferential groove, thereby The combined holding tube can be positioned with respect to the axial direction and the rotation direction. By positioning the engagement holding tube in the axial direction, for example, when the engagement holding tube is inserted into the ground or pulled out from the ground, the engagement holding tube is moved in the axial direction. Even when force is applied, it is possible to reduce a problem that the engagement holding tube is displaced from the connection portion. If the engagement holding pipe is displaced from the connecting portion, the restraining force that causes the axes of the first and second backfilling agent supply pipes to coincide with each other does not work, so the first and second backfilling agent supply pipes The connecting part is easily detached and separated.

  In the connecting structure of the backfilling agent supply pipe according to the present invention, the rotation prevention groove of the engagement holding pipe is opened from the circumferential groove in both directions parallel to the axis of the engagement holding pipe. It is characterized by.

  According to the present invention, the rotation preventing groove of the engagement holding tube is opened from the circumferential groove end in both directions parallel to the axis of the engagement holding tube. Even when a force is applied in the axial direction from both directions to the engagement holding tube, such as when inserting or withdrawing from the ground, the problem that the engagement holding tube is displaced from the connection portion is reduced. can do.

  According to the pile unfilling method according to the present invention, the backfilling agent supply pipe is disposed in the portion excavated along the outer peripheral surface of the existing pile, and the backfilling agent is supplied through the backfilling agent supply pipe. However, by pulling up the existing pile, the backfilling agent can be filled directly into the pile hole. Thereby, it becomes possible to more reliably fill the pile punching hole with the backfilling agent, and the ground deformation after the existing pile is pulled out and backfilled can be reduced. Moreover, since the drawing work of the existing pile and the filling work of the backfilling agent are performed at the same time, the construction period of the pile drawing backfilling work can be shortened.

  Further, according to the present invention, the engagement holding tube is inserted into the rotation preventing groove formed in the engagement holding tube by passing the lock convex portion protruding from a part of the outer peripheral portion of the first backfilling agent supply tube. Positioning can be performed with respect to the axial direction and the rotational direction. Therefore, when the first and second backfilling agent supply pipes are inserted into the excavation holes, even when the engagement holding pipes contact the side walls of the excavation holes, the engagement holding pipes are axially moved. It is possible to reduce a problem that the first and second backfilling agent supply pipes are displaced and separated at the connection portion.

It is a flowchart explaining each work process of the pile extraction / refilling method according to the present invention. It is sectional drawing of the ground of the existing pile vicinity in a pile heading excavation process. It is sectional drawing of the ground of the existing pile vicinity in a stand pipe setting process. It is sectional drawing of the ground of the existing pile vicinity in an outer periphery excavation process. It is sectional drawing of the ground of the existing pile vicinity in a casing extraction process. It is sectional drawing of the ground of the existing pile vicinity in a sling wire setting process. It is sectional drawing of the ground of the existing pile vicinity at the time of pulling out a casing in a sling wire setting process. It is sectional drawing of the ground of the existing pile vicinity in the backfilling agent discharge process after a backfilling agent supply pipe insertion process. It is sectional drawing of the ground of the existing pile vicinity in the existing pile pulling-up process. It is sectional drawing of the ground of the existing pile vicinity explaining other embodiment in an existing pile pulling-up process. It is sectional drawing of the ground of a pile punch hole vicinity in a stand pipe removal process. It is sectional drawing of the ground of the existing pile vicinity in a pile hole backfilling process. It is a figure explaining the positional relationship of the backfill trace of a some existing pile, and the new pile to embed next. It is the schematic which shows the whole structure of a backfilling agent supply pipe. It is a figure explaining the structure of the connection part in the elongate 1st and 2nd backfilling agent supply pipe, and the shape of an engagement holding pipe. It is a figure which shows the state before connecting the 1st and 2nd backfilling agent supply pipes in a connection part, and putting an engagement holding pipe on the outer peripheral part of a connection part. It is a figure which shows the state which put the engagement holding | maintenance pipe | tube on the outer peripheral part of the connected 1st and 2nd backfilling agent supply pipe | tube, and made the lock | rock convex part reach | attain a circumferential groove. It is a figure which shows the state which rotated the engagement holding | maintenance pipe | tube to the left direction from the state shown in FIG. 17, and reached the lock | rock convex part to the rotation prevention groove | channel. It is a figure which shows embodiment which formed the two types of circumferential groove from which length differs in one engagement holding tube. It is a figure which shows embodiment which opened two rotation prevention grooves which go to both the collar parts of an engagement holding pipe from a circumferential groove. It is a figure explaining embodiment which formed the inclined surface in the part connected from a circumferential groove to a rotation prevention groove. It is a figure explaining embodiment of the engagement holding | maintenance pipe | tube with which the circumferential groove is opening to the pipe collar part of an engagement holding | maintenance pipe | tube. It is a figure explaining other embodiment of the engagement holding | maintenance pipe | tube with which the circumferential groove is opening to the pipe collar part of an engagement holding | maintenance pipe | tube. It is a figure explaining the structure of the conventional connection part in the elongate 1st and 2nd backfilling agent supply pipe | tube, and the shape of an engagement holding pipe. It is a figure which shows the state immediately after connecting long 1st and 2nd backfilling agent supply pipes in a connection part. It is a figure which shows the state which connected the long 1st and 2nd backfilling agent supply pipes, covered the conventional engagement holding pipe on the outer peripheral part of the connection part, and fixed the engagement holding pipe with the wire. . It is a figure which shows the state which connected the long 1st and 2nd backfilling agent supply pipes, covered the conventional engagement holding pipe on the outer peripheral part of the connection part, and fixed the engagement holding pipe with the gummed tape. .

(Pile unfilling method)
Each step of the pile unfilling method according to the present invention will be described with reference to FIGS.

  FIG. 1 is a flowchart for explaining each work process of the pile unloading / refilling method. FIG. 2 is a cross-sectional view of the ground near an existing pile in a pile head excavation process. FIG. 3 is a cross-sectional view of the ground near the existing pile in the stand pipe setting process. FIG. 4 is a cross-sectional view of the ground near an existing pile in the outer periphery excavation process. FIG. 5 is a cross-sectional view of the ground in the vicinity of an existing pile in the casing drawing process. FIG. 6 is a cross-sectional view of the ground near an existing pile in the sling wire setting process. FIG. 7 is a cross-sectional view of the ground near the existing pile when the casing is pulled out in the sling wire setting process.

  FIG. 8 is a cross-sectional view of the ground near the existing pile in the backfilling agent discharge step after the backfilling agent supply pipe insertion step. FIG. 9 is a cross-sectional view of the ground near the existing pile in the existing pile pulling process. FIG. 10 is a cross-sectional view of the ground in the vicinity of an existing pile for explaining another embodiment in the existing pile pulling process. FIG. 11 is a cross-sectional view of the ground near the pile hole in the standpipe removal process. FIG. 12 is a cross-sectional view of the ground in the vicinity of an existing pile in a pile hole backfilling step.

  Next, using the flowchart shown in FIG. 1 and the sectional views of the ground shown in FIGS.

  First, in the step S12 “pile head excavation” step shown in FIG. 1, the position where the existing pile 12 is buried is investigated with reference to the site drawings and the like, and an excavator such as a backhoe as shown in FIG. 14 is used to cue the existing pile 12. And the work which removes the earth and sand near the upper part of the existing pile 12 is performed.

  Next, in the step S14 “stand pipe setting” step shown in FIG. 1, the work of embedding the stand pipe 16 around the head of the existing pile 12 is performed so that the peripheral wall of the mouth does not collapse during the pile removal work. . Then, in the next step S16 "Stand pipe peripheral backfilling" step, as shown in FIG. 3, the outer periphery of the standpipe 16 is backfilled using an excavator 14 such as a backhoe, and a pile unloading work is performed. Prepare the ground.

  Next, a crane (pile removal machine) 18 used when pulling out the existing pile 12 is placed on the ground near the existing pile 12 in the step S20 “machine set at the removal pile position” shown in FIG.

  Next, excavation is performed along the outer periphery of the existing pile 12 using the casing 20 in the step S22 “outer periphery excavation” step shown in FIG. In the outer periphery excavation step, as shown in FIG. 4, a cylindrical casing 20 having a excavation bit attached to the tip is hung using a crane 18 and positioned so that the existing pile 12 enters the casing 20. Then, the casing 20 is lowered while rotating. Thereby, it can excavate along the outer peripheral part of the existing pile 12. FIG. In the outer periphery excavation process, the casing 20 may be lowered while jet water is ejected in order to reduce excavation resistance. In FIG. 4, reference numeral 19 </ b> A is a main wire hook of the crane, and reference numeral 19 </ b> B is an auxiliary wire hook of the crane.

  Next, in step S24 “External excavation completed?” Shown in FIG. 1, the excavation depth has reached the bottom of the existing pile 12 even though excavation is performed to a depth that allows excavation using the existing casing 20. If it is determined that it is not, branching to step S26 “casing joint” process, the casing 20 is separated at the connection part that is on the ground, and a new extension casing is added in between, and the outer periphery excavation in step S22 is performed again. Execute the process.

  If it is determined in step S24 “Period excavation completed?” Shown in FIG. 1 that the excavation depth has reached the bottom of the existing pile 12, the process proceeds to the next step S28 “confirmation of existing pile edge cutting”, and the existing pile It is confirmed whether or not 12 is ready to be removed from the ground.

  Next, in step S30 “casing extraction” step shown in FIG. 1, the crane 20 is used to extract the casing 20 used for excavation from the ground as shown in FIG.

  Next, in the step S32 “sling wire setting” step shown in FIG. 1, a ring of the wire 22 for pile removal is wound around the tip of the pulled up casing 20 as shown in FIG. 6. The other end of the wire hangs on the secondary wire hook 19B of the crane. Then, the casing 20 is returned to the ground again, and the ring of the sling wire 22 is hung on the upper portion of the existing pile 12 (approximately 3 m from the upper end). In this operation, the auxiliary wire hook 19B is loosened, the wire 22 tangled at the tip of the casing 20 is removed from the tip, the auxiliary wire hook 19B is stretched again, and the wire 22 is hung on the existing pile 12. When the ring of the sling wire 22 is hung on the existing pile 12, the casing 20 from which the wire 22 has been removed is pulled up by a crane, and the casing 20 is pulled out again as shown in FIG.

  Next, the casing 20 is removed, and the excavator 14 (when the existing pile 12 is short) or the crane 18 (when the existing pile 12 is long) or the like is placed on the ground near the existing pile 12 as shown in FIG. Then, as shown in FIG. 8, the upper end of the sling wire 22 hung on the auxiliary wire hook 19 </ b> B is replaced with the main wire hook 19 </ b> B of the excavator 14 or the crane 18 to prepare for pulling out the existing pile 12. At this time, the crane 18 at the time of working the casing 20 may be used as it is, or another crane may be used.

  And it progresses to step S34 "backfilling agent supply pipe arrangement | positioning" process shown in FIG. 1, and the backfilling agent supply pipe | tube 24 is inserted in the hole excavated along the outer peripheral part of the existing pile 12. FIG. At this time, for example, the auxiliary wire hook 19B is used so that the discharge port of the backfilling agent 30 at the lower end of the backfilling agent supply pipe 24 reaches the vicinity of the bottom of the pile punching hole. When the depth of the pile punching hole is several meters or more, as shown in FIG. 14 described later, a plurality of backfilling agent supply pipes 24 are connected, and the discharge port of the backfilling agent 30 is connected to the pile punching hole. It is necessary to reach the vicinity of the bottom. The overall structure, connection structure, and connection method of the backfilling agent supply pipe 24 will be described separately later.

  When the outer periphery excavation is performed using the casing 20, a cylindrical excavation hole is opened around the existing pile 12. In general, the difference between the inner diameter and the outer diameter of the cylindrical excavation hole that opens after the outer periphery excavation using the casing 20 is about 100 to 200 mm. Therefore, the backfilling agent supply pipe 24 inserted into the cylindrical excavation hole is preferably a pipe having an outer diameter of about 80 mm or less. These dimensions are optional design items.

  A backfilling agent supply plant 26 for supplying the backfilling agent 30 is installed on the ground portion near the existing pile 12, and the backfilling agent is supplied to the upper part of the backfilling agent supply pipe 24 as shown in FIG. The elbow 25B for use and the backfilling agent supply hose 25A are connected. As the backfilling agent 30, for example, cement milk or mortar prepared according to the ground property and land quality is mixed with a fluidizing agent for pressure feeding.

  When a plurality of backfilling agent supply pipes 24 are connected and disposed, the process proceeds to step S36 “backfilling agent discharge” step shown in FIG. 1, and the backfilling agent 30 is supplied from the backfilling agent supply plant 26 as shown in FIG. The backfilling agent 30 is discharged from the discharge port of the backfilling agent supply pipe 24, and the backfilling agent 30 is stored at the bottom of the excavation hole.

  In the case where impurities 32 such as ground water, gravel, jet water used for excavation are accumulated in advance in the excavation hole, by discharging the backfilling agent 30 from the discharge port of the backfilling agent supply pipe 24, These impurities 32 rise. Therefore, it becomes possible to reduce the filling unevenness of the backfilling agent 30 in the ground, and the ground deformation can be improved.

  Next, in step S38 “existing pile pulling back-filling” process shown in FIG. 1, the sling wire 22 is pulled up using the crane 18 as shown in FIG. Since the soil and mud that have not been excavated by the casing 20 are attached to the outer peripheral portion of the existing pile 12 that has appeared on the ground as the sling wire 22 is pulled up, these soil and mud are removed when the existing pile 12 is pulled up. Perform while dropping with water pressure.

  When pulling up the existing pile 12, the backfilling agent 30 is discharged from the discharge port at the tip of the backfilling agent supply pipe 24 at the same time that the existing pile 12 is pulled out. Thus, by pulling up the existing pile 12 while supplying the backfilling agent 30 via the backfilling agent supply pipe 24, a pile punching hole is more reliably formed without creating a void below the existing pile 12 being pulled out. The backfilling agent 30 can be filled. Thereby, it becomes possible to reduce the uneven filling of the backfilling agent 30 in the ground, and the ground deformation can be improved. Moreover, since the drawing work of the existing pile 12 and the filling work of the backfilling agent 30 are performed at the same time, it is possible to shorten the construction period of the pile pulling back work.

  In addition, when the length of the existing pile 12 exceeds several meters, the upper part of the existing pile 12 pulled up as shown in FIG. continue. When all the existing piles 12 are pulled out, the arranged backfilling agent supply pipe 24 is pulled up. When a plurality of backfilling agent supply pipes 24 are connected, the engagement holding pipe 90 shown in FIGS. 15 to 17 described later is usually removed, and the individual backfilling agent supply pipes 24 are pulled up while being removed.

  Next, another embodiment of the existing pile pulling backfilling step will be described with reference to FIG. In FIG. 9, the embodiment in which only the existing pile 12 is pulled up has been described. However, in the embodiment illustrated in FIG. 10, in the existing pile pulling backfilling process, the filling agent 30 is supplied and the existing pile 12 is pulled up. The return agent supply pipe 24 is pulled up. As described above, when the backfilling agent 30 is quickly solidified by pulling up the backfilling agent supply pipe 24 in conjunction with the supply of the backfilling agent 30 and the lifting of the existing pile 12, or because the existing pile 12 is long, it is pulled out. Even when the work takes time, regardless of these conditions, the filling process of the backfilling agent 30 can be performed more reliably, and the ground deformation after backfilling can be reduced.

  When a plurality of backfilling agent supply pipes 24 are connected and used, when the backfilling agent supply pipe 24 is pulled up, the backfilling agent supply pipes 24 that have come out to the ground by the pulling up are sequentially connected. Separate and remove at the section and close the length. The backfilling agent supply elbow 25B and backfilling agent supply hose 25A are reconnected to the upper part of the backfilling agent supply pipe 24 filled in length, and the backfilling agent 30 is supplied.

  When the lifting of the existing pile 12 and the lifting agent supply pipe 24 are completed, the crane 18 and the returning agent supply plant 26 are removed. And the existing pile pulling backfill process is complete | finished. FIG. 11 shows a mode after this process is completed.

  Next, in step S42 “pile-out hole backfilling” step shown in FIG. 1, as shown in FIG. 12, the excavator 14 such as a backhoe is used to put earth and sand into the pile-out hole and backfill. Then, the pile unfilling method is completed. As described above, the pile removing operation and the backfilling operation can be performed in parallel. In this backfilling operation, the impurities 32 may be removed and backfilled in advance, or may be backfilled with the impurities 32 left.

  Next, in step S44 “stand pipe removal” step shown in FIG. 1, the stand pipe 16 arranged above the pile punch hole is pulled up, and the stand pipe 16 is removed from the pile punch hole. After removing the stand pipe 16 from the upper part of the pile hole, if necessary, the gap after removal may be backfilled with earth and sand.

  Note that the step S42 shown in FIG. 1 and the step S44 may be reversed. That is, after the existing pile pulling backfilling step in step S38, the order of the “stand pipe removal” step and the pile punching hole backfilling step may be performed.

  The pile unfilling method according to the present invention includes existing piles such as PC piles, PHC piles, BT piles, steel pipe piles, pine piles and friction piles, and existing piles such as ED piles, reverse piles and pedestal piles. It can be used for drawing out. In addition, the thickness of the existing pile that can be handled by the pile unfilling method according to the present invention depends on the inner diameter of the casing 20. At present, it is possible to handle piles with a diameter of about 2 m. On the other hand, the length (depth) of the existing pile can be handled up to about 80 m at present. Moreover, this invention is applicable also to the pile extraction / refilling method of the existing pile currently buried diagonally.

  Next, the positional relationship between the reclaimed traces 42 of a plurality of existing piles and the new pile 44 to be buried next will be described with reference to FIG. As shown in FIG. 13, when the backfill mark 42 of the existing pile overlaps with the position of the new pile 44 to be buried next, the land mark 42 of the existing pile does not match the land quality of the other ground. When the new pile 44 is buried, there arises a problem that the excavation and embedding cannot be performed vertically. In particular, when the depth of the new pile 44 is deep, it becomes a serious problem. By using the pile unloading method according to the present invention, it becomes possible to more reliably fill the pile opening hole with the backfilling agent, and the ground deformation in the backfill mark 42 after the existing pile is pulled out and backfilled is obtained. Can be reduced.

(Connection structure of backfilling agent supply pipe)
Next, the overall structure of the backfilling agent supply pipe and the connection structure thereof will be described with reference to FIGS.

  FIG. 14 is an overall structural view of the backfilling agent supply pipe 24. In the present invention, when the depth of the pile punching hole is several meters or more, a plurality of backfilling agent supply pipes 24 are connected so that the discharge port of the backfilling agent reaches the vicinity of the bottom of the pile punching hole. The connection structure and connection method are as follows.

  FIG. 15 is a view for explaining the structure of the connecting portion 80 and the shape of the engagement holding tube 90 in the long first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82. FIG. 16 shows a state before the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 are connected by the connection part 80 and the engagement holding pipe 90 is put on the outer peripheral part of the connection part 80. FIG. FIG. 17 shows the first backfilling agent connecting the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 and covering the outer peripheral part of the connecting part 80 with the engagement holding pipe 90 according to the present invention. FIG. 6 is a view showing a state in which a lock projection 88 protruded from a part of the outer peripheral portion of a supply pipe 81 is passed through an introduction groove 92 of an engagement holding pipe 90 and reaches a circumferential groove 94. In FIG. 18, by rotating the engagement holding tube 90 counterclockwise from the state shown in FIG. 17, the lock protrusion 88 is passed along the circumferential groove 94 of the engagement holding tube 90 to prevent rotation. It is a figure which shows the state which reached the groove | channel 96 and lowered the engagement holding | maintenance pipe | tube 90 below.

  As shown in FIG. 15, the end portion of the long first backfilling agent supply pipe 81 has a semicylindrical portion 83 formed by cutting it into a semicylindrical shape, and a tip inner cylindrical surface of the semicylindrical portion 83. A connecting portion 80 having an inscribed cylindrical tube protruding portion 86 with an inscribed cylindrical tube 85 for engagement attached thereto is formed. Similarly, at the end of the long second backfilling agent supply pipe 82, a semi-cylindrical portion 83 formed by cutting it into a semi-cylindrical shape, and an inner cylindrical surface of the tip of the semi-cylindrical portion 83 for engagement. A connecting portion 80 having an inscribed cylindrical tube protrusion 86 to which the inscribed cylindrical tube 85 is attached is formed.

  A lock protrusion 88 is protruded from a part of the outer peripheral portion of the connection portion 80 of the first backfilling agent supply pipe 81. The lock projection 88 is formed by, for example, welding a square plate having a side of about 2 to 4 cm or a circular plate having a diameter of about 2 to 4 cm by welding, brazing, screwing, or the like. It can be attached to the outer periphery.

  Further, as shown in FIG. 15, an introduction groove 92 that is opened in parallel with the axis of the engagement holding tube 90 is provided in the tube flange portion of the engagement holding tube 90. A side portion of the upper portion of the introduction groove 92 is an introduction portion 93 connected to a circumferential groove 94 having a groove opened in the circumferential direction of the engagement holding tube 90. The other end of the circumferential groove 94 is an anti-rotation groove 96 opened in the axial direction (in the embodiment shown in FIG. 15, above the plane of FIG. 15) away from the tube flange portion of the engagement holding pipe 90. Has been established.

  The introduction groove 92 formed in the engagement holding tube 90 is lowered when the engagement holding tube 90 is lowered along the outer periphery of the first backfilling agent supply tube 81 and the second backfilling agent supply tube 82. This is a groove through which the locking projection 88 is guided to guide the circumferential groove 94.

  The circumferential groove 94 is a groove for guiding the lock projection 88 to the rotation prevention groove 96, and even when the engagement holding tube 90 slides in the vertical direction by an external force, the rotation prevention groove 94 is provided. This is a buffer portion for preventing the lock convex portion 88 guided to 96 from coming out of the engagement holding tube 90 through the introduction groove 92.

  Even when the engagement holding tube 90 slides in the vertical direction by an external force, the rotation preventing groove 96 immediately passes through the circumferential groove 94 to the outside of the engagement holding tube 90 even when the lock holding portion 90 slides in the vertical direction. It is a groove to prevent it from streaking.

  When connecting the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82, first, the engagement holding pipe 90 is passed through the second backfilling agent supply pipe 82. Next, the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 are displaced from each other in parallel, and the connecting portions 80 of the backfilling agent supply pipes face each other. At the same time as inserting the inscribed cylindrical tube protruding portion 86 of the connecting portion 80 of the second backfilling agent supply tube 82 into the semicylindrical portion 83 formed in the connecting portion 80 of the agent supply tube 81, the second backfilling agent supply tube An inscribed cylindrical tube projecting portion of the connecting portion 80 of the first backfilling agent supply pipe 81 is fitted into the semicylindrical portion 83 formed in the connecting portion 80 of the first backfilling agent supply pipe 81 and the second filling material. The axis of the return agent supply pipe 82 is made coincident. This state is shown in FIG.

  After that, as shown in FIG. 17, the engagement holding tube 90 is moved to cover the outer periphery of the connection portion 80 of the first backfilling agent supply tube 81 and the second backfilling agent supply tube 82, and the first backfilling agent supply tube 81 is covered. The lock protrusion 88 protruded from a part of the outer periphery of the return agent supply pipe 81 is passed through the introduction groove 92 of the engagement holding pipe 90 to reach the circumferential groove 94.

  Next, as shown in FIG. 18, the engagement holding tube 90 is rotated leftward from the state shown in FIG. 17, and the lock convex portion 88 is passed along the circumferential groove 94 of the engagement holding tube 90. The rotation preventing groove 96 is reached. Generally, since the first backfilling agent supply pipe 81 is inserted into the excavation hole, the axes of the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 are arranged vertically. Therefore, when the lock projection 88 reaches the rotation prevention groove 96, the engagement holding tube 90 is lowered downward by the weight of the engagement holding tube 90, so that the lock projection 88 stops at the upper portion of the rotation prevention groove 96. It will be in the state.

  When the engagement holding pipe 90 is stopped at the upper part of the rotation prevention groove 96 as shown in FIG. 18, for example, the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 are inserted into the excavation holes. In this case, even when the engagement holding tube 90 comes into contact with the side wall of the excavation hole and the engagement holding tube 90 is displaced upward, the lock projection 88 contacts the lower end of the rotation prevention groove 96. Therefore, it is possible to prevent the engagement holding tube 90 from sliding further upward. Therefore, since the engagement holding tube 90 can be held more securely in the connection portion 80, the engagement state between the first backfilling agent supply tube 81 and the second backfilling agent supply tube 82 is restrained. I can leave.

  Next, another embodiment of the circumferential groove and the rotation prevention groove in the engagement holding pipe will be described with reference to FIGS.

  FIG. 19 is a diagram showing an embodiment in which two types of circumferential grooves 94 and circumferential grooves 94a having different lengths are formed in one engagement holding tube 90a. In addition, about the site | part which has the same function as the site | part demonstrated in FIG. 15, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The length of the parallel part in the circumferential groove 94 formed in the lower part of the engagement holding tube 90a shown in FIG. 19 is L1. On the other hand, the length of the parallel part in the circumferential groove 94a formed in the upper part of the engagement holding tube 90a shown in FIG. 19 is set to L2 longer than L1, and the engagement holding tube 90a is set according to the situation at the site. It is possible to use by changing the vertical direction of.

  For example, like the circumferential groove 94a, the circumferential groove 94a having a long parallel portion is less likely to come off the lock projection 88 guided to the rotation preventing groove 96. Therefore, when the excavation hole into which the backfilling agent supply pipe is inserted is deep or when the engagement holding pipe 90a is expected to frequently contact the side wall of the excavation hole because the excavation hole is narrow, the circular The engagement holding tube 90a may be arranged so that the groove forming the circumferential groove 94a is on the lower side, and the lock convex portion 88 is inserted into the rotation prevention groove 96 through the circumferential groove 94a for use.

  On the other hand, a circumferential groove having a short parallel portion, such as the circumferential groove 94, facilitates the operation of guiding the lock projection 88 to the rotation preventing groove 96. Therefore, when the excavation hole into which the backfilling agent supply pipe is inserted is shallow, or when the engagement holding pipe 90a is not expected to contact the side wall of the excavation hole due to the wide excavation hole, the circumferential groove 94 is used. When the engagement holding tube 90a is arranged so that the groove formed with the groove is on the lower side (the state shown in FIG. 19), the lock projection 88 is inserted into the rotation prevention groove 96 through the circumferential groove 94 and used. good.

  Next, another embodiment of the rotation preventing groove 96 will be described with reference to FIG. In addition, about the site | part which has the same function as the site | part demonstrated in FIG. 15, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  20 shows an embodiment in which, in addition to the rotation prevention groove 96 shown in FIG. 19, a rotation prevention groove 97 is provided at the other end of the circumferential groove 94 toward the tube flange portion of the engagement holding tube 90b. FIG. By opening the rotation prevention groove 97 toward the tube flange portion of the engagement holding pipe 90b, for example, the first backfilling agent supply pipe 81 and the second backfilling agent supply pipe 82 are inserted into the excavation holes. In this case, even when the engagement holding tube 90 b comes into contact with the side wall of the excavation hole and the engagement holding tube 90 b is displaced upward, the lock convex portion 88 a enters the rotation prevention groove 97. Accordingly, the engagement holding tube 90b can be prevented from further sliding upward, and the rotation operation of the engagement holding tube 90b can be restricted, so that the lock projection 88a enters the circumferential groove 94. Can be prevented. Therefore, the engagement holding tube 90b can be more securely held on the connection portion 80.

  In the embodiment shown in FIG. 20, the planar shape of the lock projection 88a is circular. As the planar shape of the locking convex portion, a rectangular planar shape as shown in FIG. 15 or the like, or a circular planar shape as shown in FIG. 20 can be used.

  Next, another embodiment of the connection shape between the circumferential groove 94 and the rotation prevention groove 96 and the rotation prevention groove 97 will be described with reference to FIG. The engagement holding tube 90c shown in FIG. 21 is a diagram illustrating an embodiment in which an inclined surface 98 is formed in a portion connecting from the circumferential groove 94 to the rotation prevention groove 96 and the rotation prevention groove 97. In addition, about the site | part which has the same function as the site | part demonstrated in FIG.15, FIG.19 and FIG.20, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 21, by forming an inclined surface 98 at a portion connecting the circumferential groove 94 to the rotation prevention groove 96 and the rotation prevention groove 97, the engagement holding tube 90c is shifted in the vertical direction and the rotation direction. Even when there is a movement, the engagement holding tube 90c rotates so that the lock projection 88 is returned to the rotation prevention groove 96 or the rotation prevention groove 97, so that the lock projection 88 is a circumferential groove. It is possible to reduce inconveniences that enter 94. Therefore, the engagement holding tube 90c can be held in the connecting portion 80 more reliably.

  Next, an embodiment of the engagement holding tube in which the circumferential groove is opened in the tube flange portion of the engagement holding tube will be described with reference to FIG. The engagement holding tube 90d shown in FIG. 22 does not have the introduction groove 92 as shown in FIGS. 19 to 21, and the circumferential groove 94 opens to the tube flange portion of the engagement holding tube 90d. It is a figure which shows embodiment of the engagement holding | maintenance pipe | tube 90d. In addition, about the site | part which has the same function as the site | part demonstrated in FIG.15 and FIGS.19-21, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 22, the tubular hook portion of the engagement holding tube 90d is cut into a semi-cylindrical shape, and the introduction portion 93 of the circumferential groove 92 is formed in the cut flange portion of the engagement holding tube 90d. However, the object of the present invention can be achieved.

  Next, another embodiment of the engagement holding tube in which the circumferential groove is opened in the tube flange portion of the engagement holding tube will be described with reference to FIG. The engagement holding tube 90e shown in FIG. 23 also does not have the introduction groove 92 as shown in FIGS. 19 to 21, and the circumferential groove 94 opened obliquely is formed in the tube flange portion of the engagement holding tube 90d. It is open. In addition, about the site | part which has the same function as the site | part demonstrated in FIG.15 and FIGS.19-22, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 23, the object of the present invention can be achieved even if the introduction portion 93 of the circumferential groove 92 opened obliquely from the tube flange portion is formed in the tube flange portion of the engagement holding tube 90d.

12 Existing pile 14 Excavator 16 Stand pipe 18 Crane (pile remover)
19A Main wire hook 19B Sub wire hook 20 Casing 22 Wire 24 Backfill agent supply pipe 25A Backfill agent supply hose 25B Backfill agent supply elbow 26 Backfill agent supply plant 30 Backfill agent 32 Impurities such as jet water 42 Filling Return mark 44 New pile 80, 980 Connection part 81, 981 First backfilling agent supply pipe 82, 982 Second backfilling agent supply pipe 83, 983 Semi-cylindrical part 85, 985 Inscribed cylindrical pipe 86, 986 Inscribed cylindrical pipe Protruding part 88, 88a Locking convex part 90, 90a, 90b, 90c, 90d, 90e, 990 Engagement holding tube 92 Introducing groove 93 Introducing part 94, 94a Circumferential groove 96 Antirotation groove 97 Antirotation groove 98 Inclined surface 992 Wire 994 Gum tape

Claims (2)

A semi-cylindrical portion formed by cutting an end portion of the long tube into a semi-cylindrical shape, and an inscribed cylindrical tube protruding portion in which an inscribed cylindrical tube for engagement is attached to the inner cylindrical surface of the tip of the semi-cylindrical portion First and second backfilling agent supply pipes each formed with a connecting portion;
The inside of the semi-cylindrical part formed in the first backfilling agent supply pipe connecting part from the state where the respective connecting parts face each other with the axes of the first and second backfilling agent supply pipes being shifted in parallel. The projecting portion of the inscribed cylindrical tube of the second backfilling agent supply pipe connecting portion is inserted into the semi-cylindrical portion formed in the second backfilling agent supply tube connecting portion. The first and second backfilling agent supply pipe connecting portions are inserted after fitting the inscribed cylindrical tube projecting portion of the agent supply pipe connecting portion to align the axes of the first and second backfilling agent supply pipes. In the connecting structure of the backfilling agent supply pipe, comprising an engagement holding pipe that restrains the engagement state of the first and second backfilling agent supply pipes by covering the outer periphery of the backfilling agent supply pipe,
A lock protrusion protruding from a part of the outer peripheral portion of the first backfilling agent supply pipe connecting portion;
A groove formed in the engagement holding tube through which the lock projection can be passed, and has an introduction portion that allows the lock projection to enter and exit at one end and at least a circle of the engagement holding tube. A circumferential groove having a groove opened in the circumferential direction, and a rotation preventing groove opened from the circumferential groove toward the axial direction of the engagement holding tube,
A connection structure for a backfilling agent supply pipe. In the connection structure of the backfilling agent supply pipe according to claim 1,
The connecting structure of the backfilling agent supply pipe, wherein the rotation prevention groove of the engagement holding pipe is opened from the circumferential groove in both directions parallel to the axis of the engagement holding pipe.

Images