JP2015187330A - Construction method of cofferdam cum steel pipe sheet pile foundation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a cofferdam cum steel pipe sheet pile foundation which can reduce a cutting removal cost and material cost of a steel pipe sheet pile constituting a partition wall when the partition wall is provided in a sunk well constituted of the steel pipe sheet.SOLUTION: A construction method of a cofferdam cum steel pipe sheet pile foundation comprises: a steel pipe sheet pile placement step of placing steel pipe sheet piles 10 (10a, 10b) and forming a sunk well; a peripheral wall forming step of forming a peripheral wall S for constituting the sunk well by placing two or more peripheral wall components constituted by connecting the steel pipe sheet piles 10 (10a, 10b) in the ground; and a partition wall forming step of forming a partition wall W defining the inside of the peripheral wall S by placing two or more partition wall components constituted by connecting the steel pipe sheet piles 10 and a plier pile 20 in the ground before or after the peripheral wall forming step or concurrently. The construction method also includes a plier pile removal step of removing the plier pile 20 for constituting the partition wall components before or after an excavation step in the sunk well for excavating the inside of the sunk well or concurrently.

Description

  The present invention relates to a method for constructing a steel pipe sheet pile foundation that also serves as a temporary cutoff.

  In the sea and rivers, the foundation of the pier must be installed under the bottom of the water. As such a foundation, a steel pipe sheet pile foundation constituted by a member called a steel pipe sheet pile in which a joint is provided on the steel pipe is used.

  As shown in FIGS. 5 and 6, the steel pipe sheet pile foundation has a lower end thereof in a state in which a plurality of steel pipe sheet piles 10 are sequentially connected in a joint portion 11 so as to have various planar shapes such as a circular shape, an oval shape, and a rectangular shape. While driving the steel pipe sheet pile 10 vertically with the connecting portion 15 according to the distance from the water bottom 1 to the water surface, the upper end of the uppermost steel pipe sheet pile 10 is raised to the water surface while driving into the ground of the bottom 1 to a predetermined depth. By arranging the joints 11 in parallel and filling the mortar or the like into the joint section 11 to make the inside of the well defined by the steel pipe sheet pile 10 a temporary cutoff, after excavating the bottom of the water in the temporary cutoff, the sand 2 from the lower layer, the concrete base 3 The steel pipe sheet pile method is used to form the bridge pier 4 in order (see Patent Document 1).

  The steel pipe sheet pile 10 uses a pile driving machine, a hammering method that is installed in the ground by hammering with a hydraulic hammer, a vibration method that is installed in the ground while applying vibration by a vibro hammer, and excavating the hollow part of the pile body It is built and built by the underground digging method installed in the ground, and after placing concrete to the design length of the temporary deadline, it is cut at a predetermined position in the water by an underwater cutting machine.

  In this way, the steel pipe sheet pile foundation by the steel pipe sheet pile method combined with the temporary cutoff is used for the construction of the pier foundation because the steel pipe sheet pile also serves as the foundation pile and the peripheral wall for the temporary cutoff, compared to other methods such as the double deadline method. It has features such as high safety during construction and greatly shortened construction period.

  By the way, the partition wall formed by juxtaposing the steel pipe sheet pile 10 in the center of the temporary cut-off formed of various planar shapes such as a circular shape, an oval shape, a rectangular shape, for example, an oval peripheral wall portion S as shown in FIG. The part W may be provided. The steel pipe sheet pile 10 constituting the partition wall W is cut and removed at a height lower than that of the steel pipe sheet pile 10 constituting the oval peripheral wall portion S before placing the reinforcing bars and concrete of the pier 4.

  However, the steel pipe sheet pile 10 constituting the peripheral wall portion S and the steel pipe sheet pile 10 constituting the partition wall portion W are both temporarily connected at the connecting portion 15 in order to facilitate the construction timing and the upper end processing. Must be built to the same height.

  Moreover, the piler 40 as shown in FIG. 11 may be used for driving a steel pipe sheet pile. The piler 40 is disposed at the top of the steel pipe sheet pile 10 that has already been built, press-fit the next steel pipe sheet pile 10, and repeatedly moves to the top of the steel pipe sheet pile 10 that has been press-fitted. Will be installed side by side. Therefore, since the pillar 40 moves along the top of the steel pipe sheet pile 10 that is sequentially driven, it is necessary that the upper ends thereof are aligned at substantially the same height.

  As described above, the partition wall W does not constitute a temporary cutoff, and even though it is finally removed, the partition wall W must be installed up to the same height as the peripheral wall S. Material costs led to increased construction costs.

JP 2013-177787 A

  The object of the present invention is to provide a steel pipe sheet pile foundation that can be used for both temporary cutting and cutting that can reduce cutting and removal costs and material costs of the steel pipe sheet pile constituting the bulkhead portion when the partition wall is formed in the well formed by the steel pipe sheet pile. It is to provide a method.

  The characteristic configuration of the construction method of the steel pipe sheet pile foundation combined with the temporary closing according to the present invention includes a steel pipe sheet pile placing process for placing a steel pipe sheet pile to form a well, and an in-cylinder excavation process for excavating the inside of the well. A steel pipe sheet pile foundation construction method comprising the provisional deadline and steel pipe sheet pile foundation, wherein the steel pipe sheet pile placing step is configured by placing a plurality of peripheral wall structural members formed by connecting steel pipe sheet piles into the ground, Before and after the peripheral wall portion forming step for forming the peripheral wall portion to be configured, or in parallel with the peripheral wall portion forming step, a plurality of partition wall portion constituent members configured by connecting steel pipe sheet piles and Yatco piles in the ground Partitioning part forming step of forming a partitioning part for placing and partitioning the inside of the peripheral wall part, and before or after the in-cylinder excavation process, or in parallel, the Yatko pile that constitutes the partitioning part constituting member It has a Yatco pile removal process to remove

  By configuring the unnecessary part of the partition wall that is not built into the ground, which is conventionally constructed of steel pipe sheet piles, with Yatco piles, the material cost of the steel pipe sheet pile and the cost of cutting and removing the steel pipe sheet pile are reduced. It becomes useless. Moreover, since the removed Yatco pile can be reused at the construction site of another temporary deadline and steel pipe sheet pile foundation, it can also contribute to the cost reduction of the whole construction.

  According to the present invention, in the case of having a partition wall in a well formed by a steel pipe sheet pile, construction of a steel pipe sheet pile foundation combined with a temporary cutoff capable of reducing cutting and removal costs and material costs of the steel pipe sheet pile constituting the partition wall portion. A method can be provided.

Illustration of steel pipe sheet pile placing process Cross section of well Explanatory drawing to remove the Yatco pile that constitutes the bulkhead Illustration of construction in the well Schematic view of the pier Top view of well (A) is explanatory drawing of a steel pipe sheet pile, (b) is explanatory drawing of a joint part. (A) is an explanatory diagram of a Yatco pile, (b) is an explanatory diagram of a joint part Illustration of steel pipe sheet pile and Yatco pile Illustration of distance piece Explanatory drawing of steel pipe sheet pile built using a pillar

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  First, the steel pipe sheet pile 10 and the Yatco pile 20 used for the construction method of the temporary-pipe combined steel pipe sheet pile foundation by this invention are demonstrated.

  As shown to Fig.7 (a), the steel pipe sheet pile 10 was attached so that it might extend in the longitudinal direction of the cylindrical main body 12 in the position facing a cylindrical main body 12 and the outer periphery of this cylindrical main body 12 on the basis of a center. A pair of joint portions 11 (11a, 11b) is provided. The joint portions 11a and 11b are formed of a pair of steel pipes having a diameter smaller than that of the cylindrical main body 12, and guide grooves 11c and 11d are formed along the longitudinal direction at positions shifted by about 180 degrees in plan view.

  As shown in FIG. 7B, the adjacent joint portions 11a and 11b insert the side edge portions of the guide grooves 11c and 11d of the joint portions 11a and 11b into the guide grooves 11c and 11d. Engage with each other by matching.

  As shown in FIG. 8 (a), the Yatco pile 20 is attached to the cylindrical main body 22 and the outer periphery of the cylindrical main body 22 so as to extend in the longitudinal direction of the cylindrical main body 22 at a position opposed to the center. A pair of joint portions 21 (21a, 21b) is provided. The cylindrical main body 22 of the Yatco pile 20 is formed to have substantially the same diameter as the cylindrical main body 12 of the steel pipe sheet pile 10, and is connected to the lower end in the longitudinal direction by being inserted into the upper end of the cylindrical main body 12 of the steel pipe sheet pile 10. A plurality of inner guide members 23 are erected on the inner surface. In addition, a suspension fitting (not shown) on which a hook of a crane that lifts the Yatco pile 20 is hooked is integrally provided at the upper end portion of the cylindrical body 22 of the Yatco pile 20. The connection between the Yatco pile 20 and the steel pipe sheet pile 10 may be provided with a cylindrical outer guide member that circumscribes the upper end of the steel pipe sheet pile 10 instead of the inner guide member 23 as described above. The steel pipe sheet pile 10 and the Yatco pile 20 may be connected by inserting the upper end of the cylindrical main body 12 of the steel pipe sheet pile 10 into the member.

  The joint portions 21 a and 21 b are formed to have substantially the same diameter as the joint portions 11 a and 11 b of the steel pipe sheet pile 10. In the joint portions 21a and 21b, guide grooves 21c and 21d having the same configuration as the guide grooves 11c and 11d formed in the joint portions 11a and 11b of the steel pipe sheet pile 10 are formed, respectively.

  As shown in FIG. 8B, the adjacent joint portions 21a and 21b insert the side edge portions of the guide grooves 21c and 21d of the joint portions 21a and 21b into the mutual guide grooves 21c and 21d. Engage with each other by matching.

  The cylindrical main body 12 of the steel pipe sheet pile 10 is connected by welding in the longitudinal direction to constitute a peripheral wall portion constituent member for forming the peripheral wall portion S of the well. In addition, it may connect in a longitudinal direction with the mechanical coupling provided in the both ends of the cylindrical main body 12. FIG. A partition wall configuration for connecting the steel pipe sheet pile 10 and the Yatco pile 20 by inserting the inner guide member 23 of the Yatco pile 20 into the upper end of the tubular main body 12 of the steel pipe sheet pile 10 to form a partition wall W that partitions the well. A member is constructed.

  Considering the workability of the connection between the steel pipe sheet piles 10 or by mechanical joints and the workability of the connection between the steel pipe sheet piles 10 and the Yatco piles 20, the joint portions 11a and 11b of the steel pipe sheet piles 10 It is not formed to both ends, and the joint portions 21a and 21b of the Yatco pile 20 are not formed to the upper and lower ends of the cylindrical main body 22 as well.

As shown in FIG. 9, on the side of the connecting portion 16 in which the inner guide member 23 at the lower end of the Yatko pile 20 is inserted and connected to the upper end of the tubular body 12 of the steel pipe sheet pile 10, In order to continue the joint part 21b of the Yatco pile 20 with the same shape joint member, the distant piece 14 is attached to the joint part 11b and the joint part 11b by fillet welding, spot welding or the like as shown in FIG. It is attached to the cylindrical main body 12 or the cylindrical main body 22 to which the joint portion 21b and the joint portion 21b are attached. In addition, the distance piece 14 is similarly provided between the joint parts 11a and 11b of the upper and lower steel pipe sheet piles 10 when the steel pipe sheet piles 10 are connected.
The distant piece 14 is composed of a steel pipe having the same diameter as the joint portions 11a and 11b of the steel pipe sheet pile 10 and the joint portion 21b of the Yatco pile 20, and guide grooves 11c and 11d of the joint portions 11a and 11b and guides of the joint portion 21b. A guide groove 14d that is continuous with the groove 21d is provided.

The distant piece 14 is not limited to the structure attached to the joint portions 11a, 11b, and 21b and the cylindrical main bodies 12 and 22 by welding, but is bolted to the joint portions 11a, 11b, and 21b and the cylindrical main bodies 12 and 22. It may be configured to be attached by a fastening mechanism such as a nut or a nut.
Moreover, the distant piece 14 does not necessarily need to be a separate body from the steel pipe sheet pile 10 and the yatko pile 20. For example, the joint portion 21 b of the yatko pile 20 extends downward from the lower end of the cylindrical main body 22. It may be.

  Using the steel pipe sheet pile 10 and the Yatco pile 20 configured as described above, the temporary pipe and steel pipe sheet pile foundation is a temporary gantry installation process, a conductive material installation process, a steel pipe sheet pile placing process, a steel pipe sheet pile joint water stop process. , Excavation in outer steel pipe sheet pile and filling concrete work process, in-cylinder excavation process, support work installation process, bottom base concrete work process, top plate concrete work process, frame concrete work process, steel pipe sheet pile cutting and removal process, temporary frame removal work It is constructed by each process such as process.

  In the temporary gantry installation process, the temporary gantry is installed in the planned construction site of the steel pipe sheet pile foundation combined with the temporary deadline by setting a vibratory hammer on the crawler crane and placing support piles in sequence. Then, the gantry 5 (see FIG. 1) is installed.

  In the guide material installation step, the guide frame installation position is centered on the installed gantry 5 and the guide frame is installed from the gantry 5 by a crawler crane to be fixed to the guide pile.

  In the steel pipe sheet pile placing process, a hammering method installed in the ground by hammering with a hydraulic hammer, etc., a vibration method installed in the ground while applying vibration with a vibro hammer, and installing in the ground while excavating the hollow part of the pile body The steel pipe sheet pile 10 is built in a predetermined position in the ground by a medium digging method or the like to form a well.

  According to the present invention, a method of constructing a steel pipe sheet pile foundation that is also used as a temporary deadline is constructed by placing a plurality of peripheral wall constituent members formed by connecting steel pipe sheet piles 10 in the steel pipe sheet pile placing step. A plurality of partition wall constituent members configured by connecting the steel pipe sheet pile 10 and the yatko pile 20 before or in parallel with the peripheral wall portion forming step for forming the peripheral wall portion S to be configured and the peripheral wall portion forming step. A partition wall forming step of forming a partition wall W that is placed in the ground and partitions the inside of the peripheral wall S.

  Specifically, as shown in FIGS. 1 and 2, in the peripheral wall forming step, the crawler crane and the pile driving machine 30 are correctly installed on the gantry 5 and the lining plate 6 and confirmed to be stable, and then an auxiliary crane is used. The lower steel pipe sheet pile 10b (10) and the auger head screw constituting the peripheral wall portion constituting member are attached to the pile driving machine 30. Thereafter, the position of the steel pipe sheet pile 10b (10) is held on the conductive material, a guide is attached, and the steel pipe sheet pile 10b (10) is built in a predetermined position. After excavating / sinking the steel pipe sheet pile 10b (10), the upper steel pipe sheet pile 10a (10) that also constitutes the peripheral wall portion constituting member is installed. The upper and lower steel pipe sheet piles 10 (10a, 10b) are welded at the connecting portion 15, the distant piece 14 is welded between the joint portions 11, and then the steel pipe sheet pile 10 (10a, 10b) is excavated and set to a predetermined depth. The same operation is repeated, and the steel pipe sheet piles 10 are excavated and set up one by one to complete the peripheral wall portion S constituting the well. The steel pipe sheet piles 10 (10a, 10b) are rooted with one or two gaps, and finally all the pipes are solidified.

  In the partition wall forming step, which is performed before or after the peripheral wall portion forming step, the crawler crane and the pile driving machine 30 are correctly installed on the gantry 5 and the lining plate 6 and confirmed to be stable. A steel pipe sheet pile 10 and an auger head screw constituting the partition wall constituting member are attached to the pile driving machine 30 using a crane. Thereafter, the position of the steel pipe sheet pile 10 is held on the conductive material, a guide is attached, and the steel pipe sheet pile 10 is built in a predetermined position. After excavating / sinking the steel pipe sheet pile 10, the Yatoko pile 20 constituting the partition wall constituent member is built. The inner guide member 23 at the lower end of the Yatco pile 20 is inserted and connected to the upper end of the tubular body 12 of the steel pipe sheet pile 10, and after the distant piece 14 is welded between the joint portion 11 and the joint portion 21, the steel pipe sheet pile 10 and the Yatco The pile 20 is excavated and submerged to a predetermined depth. For the steel pipe sheet pile 10 which is placed on the water surface from the bottom 1 and on the water surface from the water, and then cut and removed, it is connected to the steel pipe sheet pile 10 already laid using the Yatco pile 20, and the various construction methods described above. The Yatco pile 20 is sunk to a predetermined depth. The same operation is repeated, and the steel pipe sheet pile 10 and the Yatco pile 20 are excavated and set up one by one to complete the partition wall W that partitions the well. In addition, the end solidification of the steel pipe sheet pile 10 and the Yatco pile 20 is carried out at intervals of 1 to 2, and finally the total number of the pipe piles is solidified.

  As shown in FIG. 2, the pile head height of the peripheral wall part S completed by the said peripheral wall part formation process and the partition wall part W completed by the said partition part formation process is set to the same.

  In the steel pipe sheet pile joint water stop construction process, the earth and sand in the joint part 11 of the steel pipe sheet pile 10 and the joint part 21 of the Yatco pile 20 are discharged into the joint parts 11 and 21 using a mortar plant. Mortar is injected.

  In the excavation in the outer peripheral steel pipe sheet pile and the filling concrete work process, the hung maglab is suspended from a crawler crane, the pipe is excavated to a predetermined depth, and the filling concrete is placed after cleaning the pipe with an air lift. The guide material in the well is removed and removed with a crawler crane.

In the in-cylinder excavation step, the steel pipe sheet pile 10 constituting the peripheral wall portion S is filled with concrete, and the joint portion 11 of the steel pipe sheet pile 10 is filled with a water-stopping material such as mortar to stop the water. The internal water is pumped up in stages and dried up, and the inside of the well is excavated.
The method for constructing the steel pipe sheet pile foundation combined with a temporary cutoff according to the present invention uses a crawler crane before or after the in-cylinder excavation step, and as shown in FIG. A Yatco pile removing step of removing the Yatco pile 20 from the constituent members is provided. In the Yatco pile removal process, the steel pipe sheet pile 10 and the Yatco pile 20 are separated, and only the Yatco pile 20 is lifted.

  Of the partition wall portion W, an unnecessary portion that has conventionally been configured by the steel pipe sheet pile 10 is configured by the Yatco pile 20, so that the material cost of the steel pipe sheet pile 10 and the cutting and removal cost of the steel pipe sheet pile 10 are unnecessary. Become. Moreover, since the removed Yatco pile 20 can be reused at the construction site of another temporary deadline and steel pipe sheet pile foundation, it can also contribute to the cost reduction of the whole construction.

  In the support installation step, the support is sequentially installed at an appropriate height while scraping the earth and sand adhering to the inner wall surface of the peripheral wall S and collecting and discharging the soil from the well.

  In the bottom base concrete work step, as shown in FIG. 4, after the construction sand 2 is constructed, the concrete carried in by the concrete mixer truck is placed using a tremy pipe so as to have a predetermined thickness. Form.

  Further, in the top plate concrete work step, after placing the concrete of the bottom plate 3, a connector is attached to the steel pipe sheet pile 10 constituting the peripheral wall portion S by welding, and the reinforcing bars of the top plate portion are disposed, and then a concrete mixer truck is used. Place the top concrete.

  In the frame concrete construction process, after the top slab concrete is placed, the support work is dismantled and the concrete is placed in order to form the pier 4.

  In the steel pipe sheet pile cutting and removing process, after the pier 4 is completed, the formwork and scaffolding support are removed, the earth and sand are backfilled in the well and the internal and external pressures of the peripheral wall S are balanced, and then an underwater cutting machine is used by the crawler crane. After lifting and inserting into the steel pipe sheet pile 10 and cutting the steel pipe sheet pile 10 at a predetermined depth, the unnecessary steel pipe sheet pile 10 is pulled out and removed with a vibratory hammer.

  In the temporary gantry removal process, the lining plate 6 and the H steel girder are removed with a crawler crane, and the gantry pile is pulled out and removed with a vibro hammer.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. is there.

DESCRIPTION OF SYMBOLS 1 Water bottom 2 Laying sand 3 Bottom base 4 Bridge pier 10 Steel pipe sheet pile 11 Joint part 12 Cylindrical main body 14 Distant piece 15 Connection part 16 Connection part 20 Yatco pile 21 Joint part 22 Cylindrical main body 30 Pile driver 40 Piler

Claims (1)

A steel pipe sheet pile placing construction process for placing a steel pipe sheet pile to form a well, and an in-well excavation process for excavating the inside of the well,
The steel pipe sheet pile placing construction process includes a peripheral wall part forming step of forming a peripheral wall part constituting the well by placing a plurality of peripheral wall part constituting members configured by connecting steel pipe sheet piles into the ground.
Before or after the peripheral wall portion forming step, or in parallel, a plurality of partition wall constituent members configured by connecting steel pipe sheet piles and yatko piles are placed in the ground, and the partition wall portion partitioning the inside of the peripheral wall portion A partition wall forming step of forming
Construction of temporary steel pipe sheet pile foundation combined with a temporary closing line, characterized in that it includes a Yatko pile removal step of removing the Yatco pile constituting the partition wall constituent member before or after the in-cylinder excavation step. Method.

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