JP2017082490A - Construction method of rubble foundation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a rubble foundation capable of efficiently executing a series of fairing work up to leveling work even when there is irregularity on the rubble foundation.SOLUTION: A construction method of a rubble foundation includes a depth measurement step of measuring the depth by contacting its leveling surface with a leveling range, by descending from above a sea in a state of closing a glove bucket 1, a height adjustment step of adjusting its height by inputting a stone material in the leveling range by the glove bucket 1 when being deeper than the predetermined depth, by excavating the leveling range by the glove bucket 1 when the measurement depth by the depth measurement step is shallower than the predetermined depth and a leveling step of leveling its leveling range by colliding its leveling surface with the leveling range in the state of closing the glove bucket 1 after the height adjustment step. Thus, even if there is irregularity on the rubble foundation 110, its fairing work can be efficiently executed.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for constructing a rubble foundation for shaping a rubble foundation constructed on the seabed.

  Conventionally, when constructing a breakwater or the like, a foundation rubble having a substantially trapezoidal cross section (also referred to as a foundation mound) is constructed on the seabed in order to install and fix a structure such as a caisson. In this foundation rubble construction process, first, a foundation rubble is grasped and transported from a gut ship with a grab bucket, a foundation rubble is roughly constructed, and then the work of shaping the rubble foundation is performed. And when shaping the rubble foundation, the diver moved the stones one by one using a small bucket, and at the same time the diver was also leveling.

However, the following problems occur in the conventional construction method for shaping the rubble foundation.
(1) When the working water depth exceeds 15 m, the burden on the diver increases and the risk of developing decompression sickness increases.
(2) When the working water depth becomes deep, the dive time for one dive decreases, and the ascending pressure reduction time and standby time for performing continuous diving increase, resulting in a reduction in work efficiency.
(3) The leveling work by 800-1000 kg / divided foundation rubble and cover stones is very heavy because the stones are heavy, increasing the risk of developing decompression sickness. Furthermore, in recent years, the number of divers has decreased, and there is a shortage of divers.

  Thus, as a conventional technique proposed to reduce the burden on divers and level the rubble foundation, Patent Document 1 discloses a height corresponding to a structure such as a caisson installed on the underwater rubble foundation. A weight plate made of an extremely thick steel plate is fixed to the lower end of a support frame made of a steel material assembly having a structure, and travels in a height direction of the support frame from a bottom surface of the weight plate to a required portion of the support frame. An underwater rubble foundation compaction weight provided with a scale is disclosed.

JP 60-105714 A

  However, the foundation compaction weight adopted in the invention of Patent Document 1 cannot naturally hold, transport and excavate the rubble. Since it is necessary to perform the work of attaching and detaching the foundation compaction weight and the grab bucket a plurality of times, the work efficiency cannot be improved.

  The present invention has been made in view of such points, and provides a method for constructing a rubble foundation that can efficiently perform a series of shaping operations up to leveling work even when the rubble foundation has irregularities. The purpose is to do.

As a means for solving the above-mentioned problems, the present invention described in claim 1 is based on a rubble foundation constructed on the seabed using a grab bucket having a leveling surface at the lower end and capable of opening and closing. In a state where the grab bucket is closed, the grab bucket is lowered from the sea, and the leveling surface at the lower end thereof is brought into contact with the leveling range of the rubble foundation, A depth measurement step for measuring the depth of the leveling range, and when the measurement depth measured by the depth measurement step is shallower than the predetermined depth, the leveling range is excavated by the grab bucket and deeper than the predetermined depth In the case, a stone is introduced into the leveling range by the grab bucket, and a height adjusting step for adjusting the height thereof, and after the height adjusting step, the lower end of the grab bucket is closed. The smoothing surface, and leveling steps of leveling the leveling range by impinging on the leveling range, is characterized in that comprises a.
In the invention of claim 1, the grab bucket mounted on the crane can accurately measure the unevenness of the leveling range on the rubble foundation at the depth measurement step, and at the height adjustment step, the excavation can be performed. Or, the unevenness of the leveling range on the rubble foundation can be eliminated by stone throwing, and the leveling area on the bottom of the grab bucket is made uniform by the leveling step at the lower end of the grab bucket. Can be leveled.
As a result, the depth measurement step, the height adjustment step and the leveling step are performed by a grab bucket which has a leveling surface at the lower end and which can be opened and closed, which is attached to the crane, so that the work efficiency can be improved. it can.

The invention described in claim 2 is the invention described in claim 1, wherein the grab bucket has a structure that can be suspended so that the width direction perpendicular to the opening and closing direction is inclined with respect to the horizontal direction. And, when shaping the slope of the rubble foundation, an inclination step of suspending the grab bucket so that its width direction is inclined with respect to the horizontal direction so as to substantially match the slope of the slope It is characterized by including.
In the invention of claim 2, if a grab bucket having a structure that can be suspended with the width direction inclined with respect to the horizontal direction is used, the slope of the rubble foundation can be shaped without any problem. Work can be done.

The invention described in claim 3 is the invention described in claim 1 or 2, wherein the grab bucket is opened and closed so that the leveling surface is divided.
In the invention of claim 3, since the grab bucket having a function as a weight for leveling the rubble foundation is used in addition to the function of excavating, transporting and rocking stone materials, the height adjustment step and leveling are particularly performed. The steps can be performed efficiently.

  According to the present invention, even when there are irregularities on the rubble foundation, a series of shaping operations up to the leveling operation can be efficiently performed by the grab bucket attached to the crane.

FIG. 1 is a front view of a grab bucket used in a method for constructing a rubble foundation according to an embodiment of the present invention. FIG. 2 is a side view of the grab bucket of FIG. FIG. 3 is a diagram schematically showing an upper sheave and a lower sheave around which an opening / closing rope is wound. FIG. 4 is a front view of the grab bucket of FIG. 1 with a pair of shells opened. FIG. 5 is a side view of the grab bucket of FIG. 1 in a state in which the width direction is inclined with respect to the horizontal direction and is suspended by the supporting ropes. FIG. 6 is a diagram showing step by step a method of shaping a rubble foundation with a grab bucket. FIG. 7 is a diagram showing step by step a method for shaping a rubble foundation that is continuous from FIG. FIG. 8 is an enlarged view showing a step-by-step method of shaping a rubble foundation with a grab bucket.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS.
As shown in FIGS. 6 and 7, the grab bucket 1 suspended from the crane 120 of the hoist ship 100 is used when shaping the rubble foundation 110 constructed on the seabed. First, the grab bucket 1 will be described with reference to FIGS.

  As the grab bucket 1, a so-called clamshell wide bucket is employed. The structure will be described below. For convenience of explanation, the left-right direction in FIG. 1 is referred to as an opening / closing direction, and the left-right direction in FIG. In the following description of the grab bucket 1, the main structural members for shaping the rubble foundation 110 and their operations are described, and many other reinforcing members, connecting members and their connecting structures are described. Is omitted.

  As shown in FIGS. 1 and 2, the grab bucket 1 is provided at its lower end with a pair of shells 2 and 2 that are divided so as to open and close along the opening and closing direction. Each shell 2 extends by a predetermined length in the width direction. By opening and closing the lower ends of the pair of shells 2 and 2, it is possible to grasp (excavate) and carry rubble and the like. Specifically, each shell 2 has a substantially triangular shape in front view (see FIG. 1), and closes a plurality of rib bodies 4 arranged at intervals in the width direction, and a lower end opening between the rib bodies 4. And a bottom wall portion 5. In the pair of rib main bodies 4, straight portions 7 extending in the vertical direction are formed at portions facing each other. Each rib body 4 is disposed above the straight portion 7 and is connected to a shell-side connecting portion 26 of a lower sheave box 25, which will be described later. A second connecting portion 9 is formed which is disposed at a position farthest along the connecting rod 14 and is rotatably connected to the lower end of the connecting rod 14. And if a pair of shells 2 and 2 are obstruct | occluded, each linear part 7 and 7 of a pair of rib main bodies 4 and 4 will mutually contact | abut.

  The connecting rod 14 is provided corresponding to each of the pair of shells 2. A plurality of connecting rods 14 are arranged at intervals along the width direction with respect to one shell 2. Each connecting rod 14 extends substantially in the vertical direction. The lower end of each connecting rod 14 is rotatably connected to the second connecting portion 9 of each rib body 4 of the shell 2. On the other hand, the upper end of each connecting rod 14 is rotatably connected to each upper frame 36 of the upper support 35 described later. A cover body 15 is integrally provided so as to cover the connecting rods 14 and 14. The cover body 15 is formed in a plate shape. A plurality of openings 16 are formed in the cover body 15 at intervals.

  A screed member 20 is integrally connected to the lower ends of the pair of shells 2 and 2. The screed member 20 is provided with a pair of shells 2, 2 corresponding to each of bottom plates 21, 21 having a substantially rectangular shape in plan view, and a plurality of rods connecting the bottom plates 21, 21 and the lower ends of the shells 2, 2. And a support portion 22. The length along the opening / closing direction of the bottom plate 21 is set slightly shorter than the length along the opening / closing direction of the shell 2, and the length along the width direction is set to a length along the width direction of the shell 2. . The bottom surface of each bottom plate 2 corresponds to a leveling surface. When the pair of shells 2 and 2 are closed, the bottom surfaces of the bottom plates 21 and 21 of the screed member 20 are positioned on the same plane.

  Above the pair of shells 2, 2, a lower sheave box 25 is disposed at a substantially central portion in the opening / closing direction. The lower sheave box 25 extends in the width direction. The lower sheave box 25 is integrally formed with a plurality of shell side connecting portions 26 at intervals in the width direction. Each shell side connection part 26 is extended in an up-down direction. And the 1st connection parts 8 and 8 of each rib main body 4 of a pair of shells 2 and 2 are each rotatably connected with the opening-and-closing direction both ends of the lower end of each shell side connection part 26. A lower center pin 27 extending in the opening / closing direction is inserted through a central portion in the width direction below the lower sheave box 25. Further, as schematically shown in FIG. 3, four lower sheaves 29 are arranged in the lower sheave box 25 near the center in the width direction. Two of them guide one open / close rope 30 and the other two guide another open / close rope 30.

  An upper support 35 is disposed at the upper end of the grab bucket 1. A plurality of upper supports 35 are provided at intervals along the width direction. The upper frame 35 extends in the opening / closing direction and is integrally connected to the upper surface at both ends of the upper frame 36 in the opening / closing direction. It is disposed from an extending inclination setting frame 37 and an upper support body 38 that is detachably disposed on each inclination setting frame 37 via a joint pin 47. The upper ends of the pair of connecting rods 14 and 14 are rotatably connected to both ends of each upper frame 36 in the opening / closing direction. A plurality of insertion holes 40 are formed in each inclination setting frame 37 at intervals along the longitudinal direction (width direction). The upper support body 38 is disposed in the vicinity of the center in the width direction. Triangular support plates 43 and 43 are arranged on both sides of the upper support body 38 in the opening and closing direction, respectively. An upper center pin 44 is connected to each of the triangular support plates 43, 43. The upper center pin 44 rotatably supports the upper support body 38. Support members 55 and 55 are integrally connected to upper ends of the triangular support plates 43 and 43, respectively. One end of each support rope 50, 50 is supported by each support member 55, 55, respectively.

  Insertion holes 48 and 48 through which the joint pins 47 are inserted are formed at both ends in the opening and closing direction at the lower end of the triangular support plate 43. In order to suspend the grab bucket 1 by the supporting ropes 50 so that the width direction of the pair of shells 2 and 2 is not inclined with respect to the horizontal direction, as shown in FIG. Insertion holes 48, 48 and the inclination setting frame 37 in the vicinity of the center in the width direction, and spaced from each other, each insertion hole 40, 40 (the rightmost insertion hole 40, the sixth insertion from the right) The joint pins 47 and 47 are respectively inserted into the holes 40), and the triangular support plate 43 (upper support body 38) and the inclination setting frames 37 are connected.

  An upper sheave box 42 is disposed below the upper support body 38. In the upper sheave box 42, as shown in FIG. 3, two upper sheaves 52, 52 are arranged. One of the upper sheaves 52 guides one opening / closing rope 30 and the other one upper sheave 52 guides one opening / closing rope 30. At both ends in the opening / closing direction at the upper end of the upper support main body portion 38, locking portions 54, 54 for locking the ends of the opening / closing ropes 30 are formed, respectively. A pair of guide rollers 53 and 53 (see FIG. 1) for guiding the opening and closing rope 30 are disposed on both ends in the opening and closing direction on the upper surface of the upper support main body 38. As shown in FIG. 3, one end of each open / close rope 30 has a pair of guide rollers 53 and 53, two lower sheaves 29 and 29 in the lower sheave box 25, and one upper sheave in the upper sheave box 42. Guided by 52 and locked to the locking portion 54.

The other ends of the two open / close ropes 30 are wound around open / close winders (not shown) provided in the crane 120, respectively. The other ends of the two support ropes 50 and 50 are respectively wound around a support winder (not shown) provided in the crane 120.
And in order to raise / lower the grab bucket 1, the grab bucket 1 raises / lowers by driving the winder for support. Further, when opening and closing the pair of shells 2 and 2 of the grab bucket 1, the open and close ropes 30 and 30 are unwound by driving the open and close winder, and as shown in FIG. By moving the lower sheave box 25 downward, the pair of shells 2, 2 opens and closes the first connecting portions 8, 8 of each rib body 4 of each shell 2 and the shell side connecting portion 26 of the lower sheave box 25. Each of the rib portions 4 of the pair of shells 2 and 2 is finally opened apart from each other by rotating in a direction away from each other around the connection point with both ends.

  On the other hand, as shown in FIG. 1, by driving the open / close winder, the open / close ropes 30 and 30 are wound up and the lower sheave box 25 is moved upward, so that the pair of shells 2 and 2 are connected to each shell 2. The first connecting portions 8 and 8 of each rib main body 4 and the shell-side connecting portion 26 of the lower sheave box 25 are respectively rotated in directions close to each other around the connecting portions in the opening and closing direction, and finally a pair of The straight portions 7 and 7 of the rib bodies 4 of the shells 2 and 2 are in contact with each other and closed. At the time of opening and closing, the bottom plates 21 and 21 of the screed member 20 provided at the lower ends of the pair of shells 2 and 2 rotate together with the shells 2 and 2, respectively.

  In addition, in order to suspend the grab bucket 1 by tilting the width direction thereof (direction perpendicular to the opening / closing direction of the pair of shells 2 and 2) with respect to the horizontal direction by the supporting ropes 50 and 50, First, the two joint pins 47 that connect each inclination setting frame 37 and each triangular support plate 43 are removed, and the connection between them is released. Next, for example, as shown in FIG. 5, the insertion hole 40 at the other end in the opening / closing direction of the inclination setting frame 37 (the insertion hole 40 located on the leftmost side) and the lower end of the triangular support plate 43 are at the other end in the opening / closing direction. The joint pin 47 is inserted into the insertion holes 40, 48 by communicating with the provided insertion holes 48. Further, the insertion hole 40 of the inclination setting frame 37 selected to set the grab bucket 1 in a desired inclination posture (the insertion hole 40 positioned fourth from the left) and the lower end of the triangular support plate 43 are arranged at one end in the opening / closing direction. The joint pin 47 is inserted into the insertion holes 40, 48.

  Thereby, the grab bucket 1 can be suspended by the supporting ropes 50 so that the width direction thereof is inclined at a predetermined angle with respect to the horizontal direction. Even when the grab bucket 1 is suspended by the supporting ropes 50 so that the width direction of the grab bucket is inclined at a predetermined angle with respect to the horizontal direction, the opening / closing ropes 30 are wound or unwound (lowered). The opening / closing operation of the pair of shells 2 and 2 operates without any problem.

Next, a construction method for shaping the rubble foundation 110 constructed on the sea floor using the above-described grab bucket 1 will be described.
The shaping on the rubble foundation 110 constructed on the seabed is shaped in the order of the top face 110b and the slope 110a.
First, a construction method for shaping the slope 110a of the rubble foundation 110 will be specifically described with reference to FIGS.
First, the grab bucket 1 is suspended by the supporting ropes 50 so that the width direction thereof is inclined with respect to the horizontal direction (the state shown in FIG. 5). This inclination angle is made to coincide with the slope of the slope 110a. At this time, the pair of shells 2 and 2 of the grab bucket 1 are closed.

  Next, the depth measurement step is performed in a state where the hoist ship 100 is stopped and positioned at a predetermined location. As shown in FIGS. 6A and 6B, the screed member 20 provided at the lower end of the grab bucket 1 by lowering the grab bucket 1 from the sea in the depth measurement step while also referring to FIGS. 1 and 2. The bottom plate 21, 21 is brought into contact with the lower surface (evening surface) of the slope surface 110 a of the rubble foundation 110 to measure the depth of the equalizing range.

Next, a height adjustment step is performed. In the height adjustment step, when the measurement depth measured in the depth measurement step is shallower than the predetermined depth, that is, when the leveling range is convex, the pair of shells 2, 2 of the grab bucket 1 Extrude the leveling range while opening and closing the, and adjust its height. On the other hand, when the measurement depth measured by the depth measurement step is deeper than the predetermined depth, that is, when the leveling range is concave, as shown in FIG. While referring to (b), the pair of shells 2 and 2 of the grab bucket 1 grip and transport the foundation rubble (or covering rubble) from the hoist ship 100, and the foundation rubble (or covering rubble) is The height is adjusted by introducing the concave portion 112 in the leveling range. After the height adjustment step, the pair of shells 2 and 2 of the grab bucket 1 are closed.
In addition, in order to improve the leveling accuracy of the slope 110a, the depth measurement step and the height adjustment step may be repeated.

  Next, a leveling step is performed. As shown in FIGS. 7 (d) and 7 (e), referring to FIGS. 8 (c) and 8 (d), in the leveling step, the grab bucket 1 is repeatedly raised and lowered in the sea to reach the lower end of the grab bucket 1. The lower plate (leveling surface) of the bottom plates 21 and 21 of the provided screed member 20 is repeatedly collided with the leveling range of the slope 110a so as to level the leveling range. Thereby, the shaping work of one part (equalized range) of the slope 110a of the rubble foundation 110 is completed.

  Next, after the hoist ship 100 is stopped and positioned at the next predetermined location, the depth measurement step, the height adjustment step, and the leveling described above are performed for the next portion (next leveling range) of the slope 110a. Do step.

Next, a construction method for shaping the top surface 110b of the rubble foundation 110 will be described.
The grab bucket 1 is suspended by the supporting ropes 50 in a state where the width direction is not inclined with respect to the horizontal direction (the state shown in FIG. 1). At this time, the pair of shells 2 and 2 of the grab bucket 1 are closed. Thereafter, the depth measurement step, the height adjustment step, and the leveling step described above are performed, and the top surface 110b of the rubble foundation 110 can be shaped.

  As described above, in the embodiment of the present invention, when the grab bucket 1 described above is used to shape the rubble foundation 110, particularly on the slope 110a, the grab bucket 1 is changed to the slope 110a. The grab bucket 1 is lifted from the sea in a state in which the pair of shells 2 and 2 of the grab bucket 1 are closed and suspended so that the width direction thereof is inclined with respect to the horizontal direction so as to substantially coincide with the slope of A depth measurement step of measuring the depth of the leveling range by lowering and bringing the lower surfaces (leveling surfaces) of the bottom plates 21, 21 of the screed member 20 into contact with the leveling range of the rubble foundation 110; When the measurement depth measured by the measurement step is shallower than the predetermined depth, the leveling range is excavated by the grab bucket 1, and when it is deeper than the predetermined depth, the rubble for foundation (or After adjusting the height of the scrubbing member 20, the bottom surfaces 21 and 21 of the screed member 20 provided at the lower end of the grab bucket 1 are brought into a leveling range. And a leveling step of leveling the leveling range by colliding. Thereby, even when the slope 110a on the rubble foundation 110 is uneven, a series of shaping operations up to the leveling work of the slope 110a can be performed efficiently.

  Further, in the embodiment of the present invention, when shaping the top surface 110b of the rubble foundation 110, the shaping work can be efficiently performed only by omitting the inclination step which is the previous process of the depth measurement step.

  1 grab bucket, 2 shell, 20 screed member, 21 bottom plate (lower surface is leveled surface), 110 rubble foundation, 110a slope, 110b top surface

Claims (3)

It is a construction method that has a leveling surface at the lower end and uses a grab bucket that can be opened and closed to shape the rubble foundation built on the sea floor,
Depth that measures the depth of the leveling range by lowering the grab bucket from the sea with the grab bucket closed and bringing the leveling surface at the lower end into contact with the leveling range of the rubble foundation Measuring steps;
When the measurement depth measured by the depth measurement step is shallower than a predetermined depth, the leveling range is excavated by the grab bucket, and when deeper than the predetermined depth, the leveling range is set by the grab bucket. A height adjustment step to input the stone and adjust its height,
After the height adjustment step, with the grab bucket closed, the leveling step of leveling the leveling range by colliding the leveling surface of the lower end with the leveling range;
A method for constructing a rubble foundation characterized by including The grab bucket has a structure that can be suspended so that the width direction perpendicular to the opening and closing direction is inclined with respect to the horizontal direction,
When shaping the slope of the rubble foundation,
2. The rubble foundation according to claim 1, further comprising: an inclination step for suspending the grab bucket so that a width direction thereof is inclined with respect to a horizontal direction so as to substantially coincide with a slope of the slope. Construction method.   The construction method of the rubble foundation according to claim 1 or 2, wherein the grab bucket is opened and closed so that the leveling surface is divided.

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