JPH08246443A - Joint construction of great depth continuous underground wall reinforced cage - Google Patents

Abstract

PURPOSE: To promote execution efficiency by projecting steel framed joints connecting a reinforced cage in the longitudinal direction at short sides of a rectangular parallelepipedic frame, and inserting one steel plate on one side between two steel plates on the other side to joint them with a pin. CONSTITUTION: An upper side reinforced joint 4b is formed of two steel plates, and since a lower side reinforced joint 4a is held between them, shearing surfaces of a pin are separated in two places, strength thereof is promoted and, at the same time, stabilized joint is obtained without having idle in any forward, backward and sideways direction. Then, an amount of bar arrangement of an excavation section side in a reinforced cage 40 is more than that of the backward soil side, and because the center of gravity goes a little toward the excavation section side from the center line, the joints 44a and 44b are set by the center line to have eccentricity so that the reinforced cage 40 is vertically suspended. When main bars 42a and 42b of screw reinforcements are connected, a screw diameter around the end of a nut-like coupler is larger than the original diameter, and a root diameter of a thread is wider than the original size to make it easy to arrange reinforcemets. By the constitution, accuracy and stability can be promoted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, GL minus 1
It relates to a connecting structure of a reinforcing bar cage for a continuous underground wall for constructing a vertical shaft with a large depth of 00 m.

[0002]

2. Description of the Related Art Recently, the use of deep underground space has been attracting attention. In addition to the advantage that there are few troubles associated with land acquisition because the ground right does not reach the deep underground space of GL minus 100 m, noise and vibration due to construction, and the effect on the ground due to use after completion are remarkable. This is because there is a large merit due to the reduction. Taking the case of constructing a sewer tunnel, a railway tunnel, etc. at such a large depth by the shield method, first construct a well-like vertical shaft called a starting vertical shaft with a tunnel depth of 100 m, for example, at a predetermined point. In and out of workers and excavators,
The base is used to carry out "slipping" generated by excavation, and the tunnel is excavated horizontally from the bottom.

An example of a starting shaft is shown in FIG. 1 is a frame
10a, 10b, 10c, ... are columnar elements obtained by vertically dividing them, 2 is an excavated portion inside the frame 1, and 3 is back soil. The cross section of one element is 2.2m x 1.5m,
The inner dimension of the frame body 1 is 13.2 × 8.8 m. The construction procedure is as follows. 1) With a rotary excavator, etc., one element,
For example, excavating the excavated soil in the element 10a portion with bentonite liquid to a predetermined depth (100 m in this case). 2) Suspend the rebar cage inside the excavated hole. 3) Insert a tremie pipe, inject concrete into the hole, and replace the bentonite liquid with concrete. When the concrete hardens, columns of steel reinforced concrete structure are created. 4) Next, leaving the element 10b, the element 10c is similarly excavated, the rebar cage is suspended, and concrete is poured. 5) After every other element on the entire circumference is constructed, the remaining elements are sequentially constructed in the same manner. 6) When the elements are connected along the entire circumference and the continuous underground wall is formed to complete the frame body 1, the excavation part 2 surrounded by the frame body 1 is excavated to discharge the earth and sand, thereby starting the vertical shaft construction. Complete.

Here, the suspension of the rebar cage described in 2) will be further described with reference to FIG. FIG. 8 is a cross-sectional view of the excavated portion showing the suspended state of the rebar cage, and 4a, 4b ... Are blocks of the rebar cage, and 5 are inserts. Since each element has a depth (length) of 100 m, it is difficult to integrally manufacture or suspend the reinforcing bar cage inserted inside. For example, the length is 10 m and the weight is about 8 tons. It is divided into 10 to 11 blocks 4a, 4b ...

The block 4a is suspended in the excavated portion by a heavy machine such as a truck crane. Block suspended from heavy equipment
When the upper end of 4a comes close to the ground, a rod-shaped insertion member 5 called "Kanzashi" is inserted into the side surface, and the weight of the block 4a is supported by the ground through the insertion member 5, and the heavy equipment is loaded. release. Next, suspend the next block 4b with heavy equipment,
It is hung just above the block 4a. After connecting the blocks 4a and 4b up and down, temporarily lifting the whole and pulling out the insertion member 5, when it is hung down and the vicinity of the upper end of the block 4b reaches the height above the ground, the insertion member 5 is again inserted into the side surface (block 4a +
The weight of the block 4b) is deposited on the ground through the insertion member 5, and the heavy equipment is released.

Thereafter, all the blocks are suspended by repeating this operation.

[0007]

The method of constructing a vertical shaft as described above has been conventionally performed. However, until now, the depth was at most about 30 to 50 m, so the building accuracy was not so severe, and the rebar used was at most D38 (deformed bar with a nominal diameter of 38.1 mm). The direction connection structure did not require special consideration.

An object of the present invention is to solve various problems peculiar to the large depth and to efficiently construct a continuous deep underground wall.

[0009]

According to the present invention as set forth in claim 1, main frames are arranged in a longitudinal direction of a surface of a frame made of a steel frame assembled in a rectangular parallelepiped shape, and the main bars are surrounded and band cords are formed at right angles thereto. At the connection part of the deep-depth continuous underground wall rebar basket that connects the rebar cages that are arranged in the longitudinal direction, the steel frame joint that connects the frame is provided so as to project in the longitudinal direction on the short side of the rectangular frame end surface. And a strip-shaped steel plate having a pin hole at an end thereof, one steel frame joint facing up and down has two steel plates, and the other one is one and is inserted between the two steel plates, It is a connecting structure of a reinforcing bar cage for a deep underground wall characterized by being connected by a pin.

According to the second aspect of the present invention, a steel frame joint for connecting a frame, which is provided at a substantially center of a short side of an end face of a rectangular parallelepiped frame, projecting in the longitudinal direction, is provided with a rebar cage to which the frame belongs and is hung on the rebar cage. The connecting structure for a reinforcing bar cage for a large depth continuous underground wall according to claim 1, wherein the connecting structure is eccentric corresponding to the position of the center of gravity of another reinforcing bar cage to be lowered. According to the present invention as set forth in claim 3, a reinforcing bar cage is formed by arranging main bars in a longitudinal direction of a surface of a frame made of a steel frame assembled in a rectangular parallelepiped shape and arranging band bars in a direction perpendicular to the main bars. In the connecting portion of the deep depth continuous underground wall rebar basket to be connected to, the main bar is a screw rebar, the joint connecting it is a nut-shaped coupler having a screw on the inner surface, at least one end thereof In the vicinity of the portion, the diameter of the screw thread is larger than the original diameter, which is a connection structure for a reinforcing bar cage for a deep underground wall.

According to the present invention, the main bar is arranged in the longitudinal direction of the surface of the frame made of a steel frame assembled in the shape of a rectangular parallelepiped, and the band is arranged in the direction perpendicular to the main bar. In a connection portion of a deep-depth continuous underground wall reinforcing bar cage connecting the reinforcing bar cage in the longitudinal direction, the main bar is a screw rebar,
The joint for connecting this is a nut-shaped coupler having a screw on the inner surface, and at least in the vicinity of one end thereof, the width of the root portion of the screw thread is wider than the original dimension. It is a connecting structure of reinforcing bar cages for deep underground walls.

According to a fifth aspect of the present invention, a reinforcing bar basket is formed by arranging main bars in the longitudinal direction of the surface of a frame made of a steel frame assembled in a rectangular parallelepiped shape, and surrounding the main bars and arranging strips at right angles thereto. In the connection portion of the deep depth continuous underground wall for reinforcing bar basket connecting in the longitudinal direction, the main bar is a screw rebar, the joint connecting this is a nut-shaped coupler having a screw on the inner surface, at least the Large depth continuous underground, characterized in that the diameter of the thread near the one end is larger than the original diameter, and the width of the root of the thread is wider than the original dimension. It is a connecting structure of a reinforcing bar basket for walls.

[0013]

[Operation] In the present invention, by constructing two steel frame joints for connecting the frame, one on the upper side and one on the lower side, the strength is improved in response to a large depth and the mounting position of the steel frame joint is eccentric by calculating the center of gravity. As a result, the vertical and horizontal accuracy during building was secured. Furthermore, by adopting screw rebar as the main bar and specially processing the screw part of the coupler, the work of connecting the coupler was made easier.

[0014]

An embodiment of the present invention will be described with reference to the drawings. The following is a connection structure of blocks for constructing a deep continuous underground wall as described in FIGS.
FIG. 3 is a perspective view of a reinforcing bar cage 40 forming a block as viewed from above. Rebar cage 40 has a width of about 1520 mm, a thickness of about 940 mm, and a length of about 10.
In the rectangular parallelepiped of m, 10 to 11 are connected in the vertical direction, and one element of the frame is formed by placing concrete. In this figure, the horizontal direction is the part that connects with the adjacent element, the vertical direction is This is the part that becomes the wall surface of the underground wall.
The rebar cage 40 includes a frame 41 that is a combination of steel aggregates such as channel steel and chevron steel, a main bar 42 that is mainly arranged in the longitudinal direction on the surface of the frame 41, and a band bar that surrounds the main bar 42 and is arranged in a direction perpendicular to the frame. 43, a steel frame joint 44 that is attached to the end of the frame 41 and connects them vertically, and a coupler 45 for the reinforcing bars that connects the main bar 42 vertically.

FIG. 2 is a side view of the end portions of the rebar cages 40 that are vertically connected, viewed from the short side direction. The upper end of the lower rebar cage 40a and
The lower end of the rebar cage 40b connected to the upper side is shown. In the approximate center of the short side of the rectangle that is the end face of the rectangular parallelepiped frame,
A steel joint 44 is attached so as to project in the longitudinal direction.
The steel frame joints 44a and 44b are strip-shaped steel plates having pin holes at their ends.

As described with reference to FIG. 8, with the insertion member 5 inserted under the horizontal member 411 at the upper end of the frame portion of the rebar cage 40, pins are inserted into the pin holes of the steel frame joints 44a and 44b to make the steel frame structure. And the corresponding upper and lower main reinforcing bars 42a and 42b are connected by a coupler 45 for reinforcing bars. FIG. 3 is a vertical cross-sectional view of the steel joints 44a and 44b taken along the line AA in FIG. The pin is shown inserted in the upper steel joint 44b.

Conventionally, since this type of joint was composed of a single steel plate both at the top and bottom, there was only one shear plane at the pin, but in this embodiment, the upper steel joint 44b is made up of two steel plates.
Since it is composed of one steel plate and the lower steel joint 44a is sandwiched between them, the shearing surface of the pin has two places to improve the strength and there is no play in the front, back, left or right directions. It has a stable joint structure.

The frame body 1 is constructed by this continuous underground wall,
When the inner excavation part 2 is excavated, the inner side becomes a space, and the back soil 3 remains on the outer side, so that a force that pushes the frame body 1 inward by the back earth pressure acts. For this reason, in the rebar cage 40, the bar arrangement amount is changed between the excavated portion 2 side and the back soil 3 side to increase the strength on the excavated portion 2 side, so that the center of gravity of the rebar cage 40 is not on the center line of the drawing. The position is slightly closer to the excavation section 2 side. Therefore, in order to suspend the rebar cage 40 vertically, it is necessary to attach the steel frame joints 44a and 44b so as to be eccentric to the excavation side by e, as shown in FIG. As described above, an element having a total length of about 100 m is divided into 10 to 11 blocks and suspended, but the blocks are not necessarily the same shape. Therefore, when only the first rebar cage is hung, (1-i
Since the position of the center of gravity differs from that when the (th) reinforcing bar cage is suspended, it is necessary to perform weight calculation for all the reinforcing bar cages and determine the eccentricity e, that is, the mounting position of the steel joint 44.

As the reinforcing bar, especially the main bar 42, a so-called deformed bar having a projection formed on the surface is used. A special technician is required when the reinforcing bars are joined by welding butt joints, lap joints, etc., by pressure welding, or by crimping joints that crimp a sleeve with a threaded joint to the end. In addition to problems such as being affected by the weather, when the space between the reinforcing bars is narrow, the gap decreases and the concrete does not wrap around easily, which may result in insufficient filling. In the present invention, a large-diameter screw rebar called D51 (nominal diameter 50.8 mm) is adopted, and the inner surface is joined by a nut-shaped coupler having a spiral protrusion corresponding thereto.

By the way, on the outer surface of the rebar cage 40, a plurality of
For example, about 10 to 16 main bars 42 are attached to the frame 41 by welding. Now, if there is only one main bar, fit the coupler on the upper end of the main bar of the lower rebar cage, hang the next rebar basket on it, and the upper bar reaches the position of the coupler. It can be easily connected by rotating the coupler at the point and screwing it into the upper bar, but if all the main bars are welded to the frame, rotate the main bar one by one or move the main bar up and down. It cannot be adjusted. Therefore, in the manufacturing stage, rebar cages are arranged in the horizontal direction in the order to be pre-connected and set at a predetermined interval, and while connecting the coupler, the next main bar is welded to the frame, and then the coupler is detached and separated. Even in the step of screwing, since the position and phase of each screw coincides with the corresponding lower one when the above-mentioned predetermined interval is reproduced, the coupler can be screwed. However, even if it is still difficult to screw in a dozen or more couplers all at once in accordance with the fine motion lowering operation of the heavy machine in the hanging operation, the female threads of the couplers are specially processed in the present invention.

FIG. 5 is a cross-sectional view of a coupler showing a first example of special processing. The coupler is made longer than the required effective screw length by about 2 threads, and the diameter D of the screw from the upper end to about 2 threads is lengthened. Is gradually increased toward D ₀ <D ₁ <D ₂ so that the screw rebar can easily enter the coupler. On the other hand, FIG. 6 shows a second example of special processing. For a screw from the upper end to about 2 ridges, the slope H of the thread is cut and the width H of the valley H ₀ <H ₁ <without changing the diameter. It becomes larger as it goes to H ₂ and the upper end, making it easier for the screw rebar to enter the coupler. In this way, even if the threads of the coupler (nut) and the screw rebar do not completely match, the tip of the male screw can enter into the coupler by one to two threads, and thereafter, the coupler can be easily
You can screw in 45 and go.

These special processes may be performed at least on one end of the coupler, but if they are performed on both ends, it is not necessary to confirm the orientation at the time of attachment, and workability is good. Further, it goes without saying that not only one of the two means shown in FIGS. 5 and 6 but also both may be used in combination. Since the projections of the screw reinforcing bars are formed by rolling at the steel bar manufacturing stage, they are not as accurate as screws by machining. Therefore, since the coupler 45 is also manufactured with a considerable gap provided to the screw rebar, it is usual to fill the gap with an adhesive such as mortar and harden it after fastening.

[0023]

According to the present invention, the accuracy and stability of the work for suspending the blocks are improved, and the work for connecting the blocks is facilitated, so that the work for constructing the continuous deep underground wall is made more efficient. , Produces excellent effects.

[Brief description of drawings]

FIG. 1 is a perspective view of a reinforcing bar cage according to an embodiment of the present invention.

FIG. 2 is a side view showing a part of a reinforcing bar basket connected to the upper and lower sides of the embodiment of the present invention.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a partial side view showing the vicinity of a steel frame joint of a rebar cage according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing an embodiment of a coupler of the main bar of the reinforcing bar cage of the present invention.

FIG. 6 is a sectional view showing another embodiment of the coupler of the main bar of the reinforcing bar cage of the present invention.

FIG. 7 is a conceptual diagram showing a starting shaft according to the present invention.

FIG. 8 is an explanatory view showing a method of suspending a reinforcing bar cage according to the present invention.

[Explanation of Codes] 1 Frame 2 Excavation 3 Back soil 4 Block 5 Insertion material 10 Element 40 Reinforcing bar cage 41 Frame 42 Main bar 43 Rib bar 44 Steel joint 45 Coupler 411 Horizontal member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Nose 2-17-4 Shiohama, Ichikawa-shi, Chiba Kawatetsu Techno Construction Co., Ltd. (72) Toshihito Seki, 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Yokohama Yokohama Steel Within the business limited company

Claims (5)

[Claims] 1. A main bar (42) is arranged in a longitudinal direction of a surface of a steel frame (41) assembled in a rectangular parallelepiped shape, and the main bar (4) is arranged.
2) A steel frame that connects the frame at the connection part of the reinforcing bar cage (40) for deep depth continuous underground wall that connects the reinforcing bar cage (40) that surrounds the reinforcing bar cage (43) in the direction perpendicular to this frame. The joint (44) is a strip-shaped steel plate provided in the rectangular parallelepiped frame (41) on the short side of the end surface in the longitudinal direction and having a pin hole at the end, and one steel frame facing vertically. The joint structure (44) has two steel plates, and the other one is one and is inserted in the middle of the two steel plates, and is connected by a pin, which is a connecting structure for a reinforcing bar cage for a continuous deep underground wall. . 2. A steel frame joint (44) for connecting a frame provided so as to project in the longitudinal direction at approximately the center of a short side of an end surface of a rectangular parallelepiped frame (41), and a reinforcing bar cage (40) to which this frame belongs and this. The connection structure of a reinforcing bar cage for a large-depth continuous underground wall according to claim 1, wherein the reinforcing bar is eccentric in correspondence with the position of the center of gravity of another suspended reinforcing bar cage. 3. A main bar (42) is arranged in the longitudinal direction of the surface of a steel frame (41) assembled in a rectangular parallelepiped shape, and the main bar (4)
The main bar (42) at the connection part of the reinforcing bar cage for deep-depth continuous underground wall that connects the reinforcing bar cage (40) that surrounds 2) and arranges the stirrup bars (43) in the direction perpendicular to this in the longitudinal direction. Is a screw rebar, and the joint connecting them is a nut-shaped coupler (45) having a screw on the inner surface, and at least in the vicinity of one end thereof, the diameter of the screw thread is larger than the original diameter. The connecting structure of the rebar cage for continuous deep underground walls, which is characterized by 4. A main bar (42) is arranged in the longitudinal direction of the surface of a steel frame (41) assembled in a rectangular parallelepiped shape, and the main bar (4)
The main bar (42) at the connection part of the reinforcing bar cage for deep-depth continuous underground wall that connects the reinforcing bar cage (40) that surrounds 2) and arranges the stirrup bars (43) in the direction perpendicular to this in the longitudinal direction. Is a screw rebar, the joint connecting them is a nut-shaped coupler (45) having a screw on the inner surface, and at least in the vicinity of one end thereof, the width of the root portion of the thread is larger than the original dimension. Connection structure of rebar cage for deep underground wall characterized by widening. 5. The main bars (42) are arranged in the longitudinal direction of the surface of a steel frame (41) assembled in a rectangular parallelepiped shape, and the main bars (4) are
The main bar (42) at the connection part of the reinforcing bar cage for deep-depth continuous underground wall that connects the reinforcing bar cage (40) that surrounds 2) and arranges the stirrup bars (43) in the direction perpendicular to this in the longitudinal direction. Is a screw rebar, and the joint connecting them is a nut-shaped coupler (45) having a screw on the inner surface, and at least in the vicinity of one end thereof, the diameter of the screw thread is larger than the original diameter. In addition, the width of the valley of the screw thread is wider than it should be. The connection structure for the reinforcing bar cage for continuous deep underground walls.