JP4911242B2 - Reinforcement structure of existing gravity quay - Google Patents

Description

  The present invention relates to a method for reinforcing and reinforcing an existing gravity quay formed by sinking a caisson at the water's edge, and a repair and reinforcing structure thereof, and in particular, an existing quay occupying period at the time of repair can be shortened as much as possible. The present invention relates to a method for reinforcing and reinforcing a gravitational quay and a structure for improving and reinforcing the same.

  As a quay structure of a harbor, as shown in FIG. 1, there is a gravity quay where a concrete caisson 2 that forms a quay wall surface is sunk. The gravitational quay has a foundation rubble layer 4 formed in the lower part of the caisson 2 to be set up, and the caisson 2 is placed on the foundation rubble layer 4 and set in the caisson 2. Sand 9 is filled, and a top plate 10 made of concrete is provided at the upper end of the sand 9 to close it. Further, a backfill stone layer 6 is formed on the land side of the caisson 2, and an earth and sand layer 8 is provided to cover the backfill stone layer 6.

By the way, in such an existing gravitational quay, it may be necessary to reinforce for anti-aging measures or seismic reinforcement. However, as a method of such reinforcement reinforcement, Japanese Patent No. 2517951 discloses such a method. What is shown is known. As shown in FIG. 2, this construction method is to secure the stability of the caisson 2 by providing a steel pile 14 penetrating the foundation rubble layer 4 to the support ground 12 at the bottom of the existing caisson 2. Yes, it is constructed according to the following procedures (1) to (8).
(1) A steel pile 14 having a perforated portion is prepared (with a top blind plate).
(2) From the top surface of the top plate 10 of the caisson 2, an excavator having a cutting edge provided at the tip used for boring or the like is attached to the guide pipe, and excavated to the top surface of the bottom plate of the caisson 2.
(3) Excavation of a slightly smaller diameter from the guide pipe is performed up to the bottom surface of the foundation rubble layer 4 as in (2) above.
(4) The steel pile 14 of the above (1) is rooted into the supporting ground 12 with a vibro hammer or a diesel hammer, and the perforated part is positioned in the liquefied ground and the foundation rubble layer 4 part.
(5) The upper part of the steel pile 14 is backfilled with stone.
(6) Install the lid 14a. Drill holes are formed in the caisson bottom plate for integration of the lid 14a by a diver or from the top surface of the top plate 10 of the caisson 2.
(7) Remove the guide tube and refill the filled sand 9.
(8) Repair the upper surface concrete (top plate 10) of the caisson 2.

Japanese Patent No. 2517951

  However, in the repair and reinforcement of the existing gravity type quay wall performed in the construction procedure as described above, in order to drive the steel pile 14 at the bottom of the caisson 2, the top plate 10 of the caisson 2 is considerably different. Since a large excavator must be installed, a large space is occupied during the construction, and the quay cannot be operated during the construction.

  Moreover, since it is necessary to provide the lid | cover 14a for integrating the upper end part of the steel pile 14 with the bottom slab of the caisson 2, since the construction of the said lid | cover 14a must be performed in the bottom part in a guide pipe, the said operation | work is very troublesome. Annoying.

  Furthermore, after the steel pipe 14 is placed, the inside sand 9 must be filled again into the caisson 2. In addition, when the good ground 14 is in a deep place, the drilling depth becomes large. Therefore, the construction period was prolonged and the construction cost was disadvantageous.

  The present invention has been made in view of the above points. The purpose of the present invention is to reduce the quay occupation period and space for construction as much as possible, and to reduce the size of the quay as much as possible. Rehabilitation of existing quay-type wharf that can be easily fixed by arbitrarily setting the fixing position with the construction work and the preparatory work, and can effectively obtain sufficient anti-falling moment strength and sliding resistance strength It is to provide a reinforcing structure.

  The existing gravity quay repair and reinforcement structure according to the present invention is an existing gravity quay repair and reinforcement structure formed by sinking a caisson at the water's edge, and concrete is filled into a cylindrical steel plate. A new construction that is arranged on the land side at a predetermined distance from the caisson, and the lower end of the caisson is driven up to a predetermined depth, and a lock formed on the top plate of the upper end of the caisson A new tie material that extends from a portion toward a predetermined height position inside the steel plate of the preparatory work and has both ends fastened to the steel plate and the locking portion of the top plate, and The tie material is installed so as to be inclined downward from the existing caisson side toward the new construction work (claim 1).

In this case, the newly-prepared construction can be installed in a non-liquefied layer with a predetermined depth (claim 2).
Alternatively, a configuration may be adopted in which a plurality of the new constructions are provided at appropriate intervals along the extending direction of the existing caisson (Claim 3).

  Moreover, the steel plate which forms the outline of the said new construction work can be made into the structure which is a steel pipe (Claim 4).

  Moreover, the steel plate which forms the outline of the said new construction work can be made into the structure which is a steel sheet pile (Claim 5).

  In addition, the newly-prepared construction can be formed in a continuous wall shape along the extending direction of the existing caisson, and a plurality of the new tie materials can be arranged in parallel at a predetermined arrangement pitch. (Claim 6).

  According to the repair and reinforcement structure of the existing gravity type quay of the present invention configured as described above, at a predetermined height position of the cylindrical steel plate placed and arranged from the land portion on the land side at a predetermined distance from the existing caisson. Toward the top of the existing caisson, drilled from the locking part formed on the top plate, through which the steel plate and the existing caisson are connected and fixed with a new tie material, and the cylindrical steel plate contains concrete. The quay occupancy during the construction period must be stopped on a part of the existing caisson and the idle land on the back side of the land that is a predetermined distance away from the existing caisson. This eliminates the need to dig up the land near the existing caisson. Therefore, it is possible to greatly shorten the quay occupancy time associated with the repair and reinforcement work and reduce the name of the occupancy space as much as possible, thereby ensuring the quay operating time as much as possible.

  Furthermore, the construction period can be shortened and the construction cost can be reduced as compared with the conventional construction method in which a steel pipe is placed and reinforced at the bottom of the existing caisson.

  In addition, the new preparatory work in which concrete is filled in a cylindrical steel plate not only can be formed with high rigidity, but also requires a new tie material that connects the cylindrical steel plate and the existing caisson. Accordingly, the steel plate can be easily fixed by being connected to an arbitrary height position of the steel sheet, and sufficient anti-falling moment strength and sliding resistance strength can be obtained by effectively reinforcing the existing caisson.

  In addition, it is possible to cope with the liquefaction phenomenon by inserting the lower end of the new construction work into the non-liquefied layer for a predetermined length.

It is a longitudinal cross-sectional view which shows the structure of the existing caisson quay used as the application object of this invention. It is a longitudinal cross-sectional view which shows the reinforcement structure of the existing gravity type quay wall in the past. BRIEF DESCRIPTION OF THE DRAWINGS It is the longitudinal cross-sectional view which shows the example of 1st Embodiment of the repair reinforcement structure of the existing gravity type quay wall concerning this invention, and shows the state at the time of construction completion. FIG. 5 is a diagram schematically showing a plane cross section of FIG. 4. It is a longitudinal cross-sectional view which shows the initial state in the middle of construction of the example of 1st Embodiment. It is a longitudinal cross-sectional view which shows the tie material installation completion state in the middle of construction of the 1st Embodiment. It is a schematic plan view which shows the 2nd Example of the improvement reinforcement structure of the existing gravity type quay wall concerning this invention. It is a schematic plan view which shows the example of 3rd Embodiment of the improvement reinforcement structure of the existing gravity type quay wall concerning this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 3 to 6 show a first embodiment of the existing gravity quay repair and reinforcement structure according to the present invention, FIG. 3 is a longitudinal sectional view showing a state when the construction is completed, and FIG. 4 is a schematic view thereof. FIG. 5 is a longitudinal sectional view showing an initial state during construction, and FIG. 6 is a vertical sectional view showing an installation end state of a tie material during construction.

  In these figures, 2 is an existing caisson, 4 is a basic rubble layer, 6 is a backfill stone layer, 8 is a soil and sand layer, 9 is a filling sand, 10 is a top plate, and 12 is a support layer. In other words, this embodiment shows an example of repair and reinforcement for the existing gravity quay shown in FIG.

  As shown in FIG. 3 and FIG. 4, the existing caisson 2 is provided on the land side at a predetermined distance from the existing caisson 2, and the new caulk 19 and the existing caisson 2 and the existing caisson 2. It is reinforced by a tie material 24 connecting the upper end of the land side.

  In the repair and reinforcement, as a first step, as shown in FIG. 5, a plurality of shafts 18 are located at a predetermined distance from the existing caisson 2 to the land side along the extending direction of the existing caisson 2. Formed. The shaft 18 is formed by surrounding the periphery with a steel plate in a cylindrical shape and excavating the inside thereof. In the embodiment of the illustrated example, a steel pipe 20 is used for the steel plate that forms the outline of the shaft 18.

  A plurality of the steel pipes 20 are placed and set up at appropriate intervals. In the illustrated example, the steel pipes 20 are arranged at a predetermined pitch corresponding to the formation pitch of the partition walls 2a that divide the interior of the caisson 2 into a lattice shape. Further, the lower end portion 20a of each steel pipe 20 is provided by being rooted at a predetermined depth in a non-liquefied layer 15 such as a gravel layer that does not cause liquefaction.

  When the upsetting of the steel pipe 20 is finished, the earth and sand inside the steel pipe 20 is excavated and removed, and the shaft 18 is formed. In addition, on the existing caisson 2 side, the land-side end portion is formed on the land-side end portion of the top plate 10 provided at the upper end portion of the existing caisson 2 so that the locking portion 30 of the tie material 24 is formed. The opening 26 is formed by cutting along the extending direction 2. Note that a retaining plate 27 is provided in advance on the side of the opening 26 in order to prevent the sediment layer 8 from collapsing.

  And when the said shaft pit formation process and a top plate cutting process are complete | finished, a new tie material installation process will be performed next. In this new tie material installation process, as shown in FIG. 6, concrete 22 is first placed to a predetermined height inside the steel pipe 20. Here, the height position of the placement surface is set to be approximately 1 m below the locking height position of the tie material 24 in view of the locking workability of the tie material 24. In addition, it is desirable to determine the locking height position of the tie material 24 in consideration of the overturning moment that the caisson 2 receives due to earth pressure, seawater water pressure, and the like, and various conditions that affect the sliding. Here, if the locking position is set so that the tie material 24 is inclined downward from the existing caisson 2 side toward the steel pipe 20, a horizontal force is applied to the existing caisson 2, and the tie material 24 is tensioned. When it acts, the existing caisson 2 can be pressed downward by the vertical component force, and the frictional force at the bottom of the existing caisson 2 can be increased so that the sliding of the bottom of the existing caisson 2 in the horizontal direction can be suppressed. become.

  Further, a locking portion 30 for locking one end portion of the tie material 24 is formed at the upper end portion of the caisson 2 exposed by cutting the top plate 10. The engaging portion 30 has a substantially L-shaped longitudinal section, and is provided to be engaged with the upper end surface and the inner wall surface of the outer peripheral vertical wall 2b located at the land side end of the existing caisson 2. A slope is formed at the outer corner of the L-shape, and the slope serves as a locking surface 30 a of the tie material 24. The inclination angle of the locking surface 30 is set to an angle orthogonal to the arrangement angle of the tie material 24 arranged to be inclined downward.

  Next, a drilling machine 28 is installed on the side sea side of the locking surface, and a drilling hole is formed by drilling from the upper end side of the existing caisson 2 toward the steel pipe 20. The tie material 24 is inserted and arranged. The drilling holes are sharply formed from the locking surface 30a of the locking portion 30, and are formed by penetrating the locking portion 30 and the steel pipe 30, and the tip of the tie material 24 is penetrated through the steel pipe 20 and protrudes into the shaft 18. .

  Here, the drilling is performed by a small-diameter propulsion method as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-336389. The outline of this small-diameter propulsion method will be described. In this method, the outer pipe and the laying pipe are pushed into the ground, and at the same time, the ground is hit and excavated by the air hammer device at the tip of the outer pipe. A center bit and a drum cutter are attached to the head of the hole drilling machine 28, and the ground is cut by them, and the compacted earth and sand are taken in from the opening of the cutter face along with the propulsion by the propulsion device. The ground holding of the face is performed by pressing the drum cutter against the ground with a base machine to bring the whole face of the face into a compacted state and applying water pressure to the face. And according to the said construction method, the drilling machine 28 is installed in a space of about 2 m in circumference, and a small-diameter drilling hole with a diameter of about 15 cm can be excavated over a length of about 100 m. In addition, it has a position measurement system using an electronic theodolite with a TV camera and a direction correction function using an eccentric excavation method, enabling highly accurate drilling.

  And if the front-end | tip of the said tie material 24 protrudes in the shaft 18 from the drilling hole, the front-end | tip will be fixedly fixed to the inner surface of the steel pipe 20 via a spacer. That is, a male thread part is integrally provided at the tip of the tie material 24, and this male thread part is fastened and fixed with a nut through a spacer that contacts the inner surface of the steel pipe 20. Further, a water stop material is provided between the drilling hole and the newly installed tie material 24 and between the steel pipe 20 and the tie material 24 to perform a water stop treatment. After the punching, the hole drilling machine 28 is removed, and one end of the tie material 24 is fixedly fixed to the locking surface 30a of the locking portion 30 via a spacer. This fixing may be done by fastening with a nut similar to the tip or welding. Further, the steel pipe 20 may be provided with an opening for inserting the tie material 24 in advance at the intended fastening position.

  When the new tie material installation process is completed, a concrete filling process into the shaft 18 is performed next. This concrete filling process is performed in order to form the steel pipe 20 into a steel pipe pile having a function as a newly-prepared construction 19 by filling the steel pipe 20 with the concrete 22 over its entire length during filling. is there. That is, the steel pipe 20 forms the outline of the newly-prepared construction 19. Then, after filling the concrete 22, it can be formed into a steel pipe pile which is an extremely high-strength preparatory work. In addition, the excavated opening 26 at the upper end of the existing caisson 2 is also filled with concrete 22 in the remaining opened opening portion on the side of the locking portion 30 after the drilling machine 28 is removed. 10 and a smooth surface.

  The diameter of the steel pipe 20 is preferably about φ1500 to 2000 mm. The new tie material 24 has a length of about 30 m. However, since the drilling machine 28 is installed on the ground, the tie material 24 can be continuously supplied by using either a rod material or a rope. Is possible.

In the illustrated example, the lower end of the steel pipe 20 is embedded in the non-liquefied layer 15, but this is a setting when it is necessary to consider the liquefaction phenomenon, and it is not necessary to deal with the liquefaction phenomenon. In this case, the lower end of the non-liquefied layer 15 may be stopped.
In the illustrated example, the top plate 10 is opened by opening to provide the locking portion 30, but a concave portion having a locking surface inclined on the upper surface side of the top plate 10 is formed by excavation. Also good.

  In the repair and reinforcement structure of the existing gravity type quay constructed as described above, the quay occupation during the construction period is part of the existing caisson 2 and the land side behind the existing caisson 2 sufficiently away from the land Since construction can be performed while being stopped at a part of the idle land, it is not necessary to dig up the land area near the existing caisson 2. For this reason, the quay occupying time accompanying the repair and reinforcement work can be greatly shortened, and the quay operating time can be secured as much as possible.

  FIG. 7 is a plan view showing a second embodiment of the existing gravity quay repair and reinforcement structure according to the present invention. Here, in the figure, the same members as those in the first embodiment described above are denoted by the same reference numerals, detailed description thereof is omitted, and the differences will be described in detail below.

  As shown in the drawing, in the illustrated example, in order to form the outer wall of the shaft 18 that is finally set as a new construction 19, the steel pipe 20 is replaced with the steel pipe 20 described above instead of the steel pipe 20. A sheet pile 20a is used. That is, the steel sheet pile 20a is driven into a rectangular shape and formed into a cylindrical shape. That is, the second embodiment is the same as the first embodiment shown in FIGS. 3 to 6 except that the steel sheet pile 20a is used for a cylindrical steel plate that will form the outline of the newly-prepared construction 19. The construction is basically the same as the shaft formation process, top plate cutting process, new tie material installation process, and concrete filling process.

  FIG. 8 is a plan view showing a third embodiment of the existing gravity quay repair and reinforcement structure according to the present invention. Even in the third embodiment, the steel sheet pile 20a is still used for the steel sheet to be cast in the cylindrical shape, but here, the steel sheet pile 20a is arranged in parallel along the extending direction of the existing caisson 2 and is a horizontally long groove. The shaft 18 is formed in a shape. That is, when the shaft 18 is formed as a new construction 19 after the concrete 22 is cast, it will have a continuous wall shape. Moreover, in the construction, basically the same shaft forming process, top plate cutting process, newly installed tie material installation process, and concrete filling process are performed.

2 Caisson 4 Foundation rubble layer 6 Backfilling stone layer 8 Earth and sand layer 9 Filled sand 10 Top plate 12 Support layer 18 Standing layer 19 Preparatory work 20 Steel pipe 20a Steel sheet pile 22 Concrete 24 Thai material 26 Opening 28 Drilling machine 30 Locking part 30a Locking surface

Claims (6)

It is a renovation reinforcement structure of the existing gravity type quay formed by sinking caisson at the waterside,
A new construction work that is filled with concrete in a steel plate formed in a cylindrical shape, and is arranged on the land side at a predetermined distance from the caisson, and the lower end portion is driven to a predetermined depth and stood. When,
Extending from a locking portion formed on the top plate of the upper end of the caisson toward a predetermined height position inside the newly installed steel plate, both ends are connected to the steel plate and the locking portion of the top plate. Newly fixed Thai material,
Have
The tie material is installed inclined downward from the existing caisson side toward the newly-prepared construction.
Renovation and reinforcement structure of existing gravity type quay characterized by that.   The renovation and reinforcement structure for an existing gravity type quay according to claim 1, wherein the new construction is installed in a non-liquefied layer with a predetermined depth.   The renovation reinforcement of the existing gravity type quay according to any one of claims 1 and 2, wherein a plurality of the new construction works are provided at appropriate intervals along the extending direction of the existing caisson. Construction.   The structure for repairing and reinforcing an existing gravity quay according to any one of claims 1 to 3, wherein the steel plate forming the outer wall of the new construction work is a steel pipe.   The steel sheet pile which forms the outline of the newly-prepared construction work is a steel sheet pile, The reinforcement reinforcement structure of the existing gravity type quay wall in any one of Claims 1-3 characterized by the above-mentioned.   The said new laying work is formed in a continuous wall shape along the extending direction of the existing caisson, and a plurality of the new tie materials are arranged in parallel at a predetermined arrangement pitch. Item 3. The structure for repair and reinforcement of an existing gravity quay according to either item 1 or 2.

Images