JP3314299B2 - Earth retaining device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil retaining device and a trench excavation method using the same, and particularly to a device which is easy to transport and handle and can perform retaining without connecting a plurality of unit retaining devices vertically. The present invention relates to an apparatus and a construction method capable of performing backfill work of earth and sand without any trouble.

[0002]

2. Description of the Related Art For example, in sewerage construction, a so-called trench excavation method of excavating a trench in the ground, laying a sewer pipe, and backfilling sediment is widely used. Sometimes sewer pipes are buried deep. In such a case, since the excavated trench wall surface is likely to collapse, it has been practiced to secure the worker's safety by retaining the trench soil wall surface.

[0003] Usually, there are a guide rail system and a box system in the earth retaining device, but a box system is often adopted from the viewpoint of workability and the like.

As shown in FIG. 7, such a box-type retaining device has a pair of retaining plates 110, 110 opposed to each other, and joints are provided on inner surfaces on both sides thereof. , 110
Are connected by cutting beams 102 to form a unit retaining device 100, and a plurality of unit retaining devices 100... Are vertically connected (for example, Japanese Utility Model Publication No. 58-47101,
Etc.).

In the case of excavating a deep groove of 3 to 4 m, while excavating a groove in the ground using a power shovel or the like,
BACKGROUND ART An earth retaining device in which a plurality of unit earth retaining devices are vertically connected is suspended and installed in an excavation trench, and an earth retaining plate is pressed against an outer earth wall surface to be earthed.

[0006]

However, when backfilling excavated earth and sand such as crushed stones brought from other places into excavation trenches, the above-mentioned earth retaining device is pulled out by the thickness of the earth and sand, and the earth and sand is removed to a predetermined depth. Since it is necessary to back-fill and compact by 0.2 m to 0.3 m in thickness and repeat such work, the back-filling work of earth and sand becomes very complicated as the upper end portion of the retaining device protrudes from the ground and becomes later. There was a problem.

Further, since the heavy earth retaining device is lifted up and pulled out, a large power shovel, a crane or the like must be used because a large pulling force is required. There was a problem that it was difficult.

[0008] Of course, it is only necessary to disconnect the unit retaining device when pulling out the retaining device. However, it is very complicated to connect the unit retaining device and disconnect the connection every time excavation and backfilling is performed at the work site. Therefore, the construction period becomes longer.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a soil retaining device capable of retaining a soil without connecting unit retaining devices vertically.

[0010]

SUMMARY OF THE INVENTION Therefore, a soil retaining device according to the present invention comprises at least two box-shaped mortar plates which are swingably connected by a pair of opposing retaining plates by right and left cutting beams extending therebetween. In a soil retaining device that is used by vertically connecting unit retaining devices and digging a digging trench, the lower unit retaining device is located above a space formed by a retaining plate and a cutting beam of the upper unit retaining device. The upper unit soil retaining device is formed in a size that can be inserted from the lower unit soil retaining device, and the upper unit soil retaining device can be used in an unconnected state, and the upper unit soil retaining device is weaker against earth pressure than the lower unit soil retaining device. While being constructed in a structure, a hanging hook portion is provided on a retaining plate of each of the unit retaining devices, and each of the unit retaining devices can be suspended.

One of the features of the present invention resides in that the lower unit retaining device is formed to have a size that can be accommodated in the upper unit retaining device. Thereby, without connecting the upper and lower unit retaining devices, the soil wall of the excavation trench can be retained, and when backfilling the sediment, the upper unit retaining device is left as it is and only the lower unit retaining device is lifted. It can be pulled out, and the work of backfilling earth and sand will not be hindered.

It is sufficient that the earth retaining device has at least two unit earth retaining devices. Considering a case where a trench having a depth of 3 to 4 m is excavated, it is preferable that the earth retaining device is comprised of three or four unit earth retaining devices. . The connection structure is not particularly limited as long as the retaining plate and the cutting beam can be connected to each other so as to be swingable. For example, the connection structure shown in the following embodiment can be adopted.

Another feature of the present invention resides in that the upper unit retaining device is configured to be weaker against earth pressure than the lower unit retaining device. In the conventional earth retaining device, the unit earth retaining devices are vertically connected, and it is not known which unit earth retaining device is located upward depending on a combination situation, so that they have to be manufactured to the same size and strength. However, when examining the earth pressure in the excavation trench, the earth pressure is large in deep places, but small in shallow places. For example, in the case of clay mixed with gravel, 2.7 tons / m ^{3 at} a depth of ³ m, 1.8 tons / m ^{3 at} a depth of 2 m, and 0.9 ton / m ^{3 at} a depth of 1 m. ³ earth pressure. On the other hand, in the present invention, as described above, the dimensions of the unit soil retaining device are different in the vertical direction, and the upper and lower unit retaining devices are predetermined, so that the upper unit retaining device can have a weak structure. This allows
It is possible to reduce the weight of the earth retaining device as a whole, and to improve the transportability and handleability in combination with the fact that the unit earth retaining device can be used in an unconnected state.

[0014] The method of making the upper unit soil retaining device a weak structure may be performed, for example, by changing the material, but there is a concern about a cost problem. On the other hand, the unit retaining device is generally configured such that retaining bars are fixed to four outer edges of an outer plate having a rectangular retaining plate, and vertical or horizontal reinforcing bars are fixed between the reinforcing bars. Therefore, it is preferable to configure the upper unit retaining device to have a weak structure by reducing the thickness of the outer plate of the retaining plate or reducing, reducing, or reducing the thickness of the reinforcing bars of the retaining plate.

The hanging hook portion may be formed by attaching a J-shaped hook or eyeglass bolt to the retaining plate, or may be formed by forming a hook hole in the reinforcing bar of the retaining plate. Further, according to the present invention, it is possible to provide a trench excavation method in which a trench is excavated using the above-described earth retaining device, a buried object is laid, and earth and sand are buried.

That is, in the trench excavation method according to the present invention, when excavating a trench in the ground, laying a buried member in the excavation trench and backfilling earth and sand, a pair of opposed retaining plates extending between the pair of left and right retaining plates are provided. It is constituted by at least two unit retaining devices which are swingably connected by a cutting beam and are configured in a box system, and the second unit retaining device is formed by a retaining plate and a cutting beam of the first unit retaining device. The first unit earthing device is formed in a size that can be inserted from above into the space to be inserted, and the first unit earthing device is configured to be weaker against earth pressure than the second unit earthing device. Excavating the ground with a width and a depth substantially corresponding to the interval and height of the pair of retaining plates of the first unit retaining device, and placing the first unit retaining device upward in the excavated upper wide groove; From above and installed above Sat wall the earth retaining rice of Habamizo, the second
Excavating below the upper wide groove with a width and a depth substantially corresponding to the interval and height of the pair of retaining plates of the unit retaining device of the second type, and installing the second unit retaining device in the excavated lower narrow groove. Is suspended from above and installed through a space formed by the retaining plate and the cutting beam of the first unit retaining device to retain the soil wall surface of the lower narrow groove. .

The unit retaining device may be installed after excavating at once, or may be installed by pushing the unit retaining device downward while excavating. In addition, since the second unit retaining device has a size that can be accommodated in the first unit retaining device, the dimensions of the first and second unit retaining devices are properly set, and the second unit retaining device is placed in the lower narrow groove. When installing the second unit retaining device, the inner surfaces of the pair of retaining plates of the first unit retaining device are preferably used as guide surfaces.

Also, as described above, since the upper and lower unit retaining devices are not connected to each other and have a wide and narrow relationship, a different conventional method is employed when backfilling the excavation trench with earth and sand. it can. That is, the second unit retaining device is lifted up, pulled out by the backfill thickness of the sediment, backfilled with the backfill thickness in the lower narrow groove, and compacted. After the thickness of the backfill is pulled out, the soil and sand are backfilled with the backfill thickness on the compacted soil and rolled, and the above-described series of operations are repeated to complete the backfill of the lower narrow groove, The first unit earth retaining device is lifted up and pulled out by the backfill thickness of the earth and sand, and the earth and sand is buried back in the upper wide groove at the back thickness and rolled, and the first unit earth retaining device is lifted to remove the earth and sand. It is possible to adopt a method of drawing back only the thickness of the backfill, backfilling the sediment with the backfill thickness on the compacted sediment, rolling, and backfilling the upper wide groove by repeating the above series of operations. .

[0019]

According to the present invention, the lower unit soil retaining device is dimensioned so as to be accommodated in the upper unit soil retaining device. Can be retained. As a result, when backfilling the sediment, it is possible to lift and pull out only the lower unit retaining device while leaving the upper unit retaining device as it is,
It is possible to solve the problem that the backfilling work of the earth and sand is hindered as in the related art.

[0020] Moreover, since it can be easily pulled out with a small power shovel or the like, a trench excavation work can be easily performed even in a narrow and complicated work site.

Further, since the upper unit soil retaining device has a structure resistant to earth pressure as compared with the lower unit soil retaining device, the overall weight of the soil retaining device can be reduced and the unit retaining device can be used alone without connecting the unit retaining device. Properties and handleability can be greatly improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the drawings. 1 to 6 show a preferred embodiment of the present invention. In the figure, the soil retaining device 10 is configured by a combination of first, second and third, ie, upper, middle and lower unit retaining devices 20, 30, and 40.

The unit retaining device 20 in the upper stage is formed in a box system by oscillatingly connecting a pair of opposed retaining plates 21, 21 with a pair of upper and lower right and left cutting beams 22 extending in the width direction. The retaining plate 21 is a steel plate (outer plate) having a length of 3440 mm and a height of 1000 mm as shown in FIG.
Reinforcing bars 211 composed of U-shaped channels are provided on the four outer edges of one surface of the 210. However, the reinforcing bars 211 are fixed to the lower edge at a position 80 mm from the lower edge of the iron plate 210. The five reinforcing bars 211 extending in the vertical direction between the reinforcing bars 211, 211 are further combined with one reinforcing bar 211 extending in the lateral direction between the upper and lower reinforcing bars 211, 211.
Is fixed. Also, reinforcement bars 2 on both sides
11 and 211 have a pair of vertically long joint holes 212 and 2.
12 are formed at predetermined intervals above and below, and the cutting beam 22 is swingably connected by the joint hole 212 and the joint 50.

In the joint 50, one end of the connecting pin 51 is inserted into the joint hole 212 and is prevented from falling off by the enlarged base 52.
It has a length of 30 mm, and a nut 53 is fixed to the outer end thereof. A pipe 54 having an external thread engraved on the outer peripheral surface is screwed into the nut 53, and the pipe 54 and the end face of the reinforcing beam 211 are screwed. A rubber ring 55 and a metal ring 56 are interposed therebetween, and the other end of the connection pin 51 is inserted into the pipe 54 and is prevented from coming off by a lock pin 58.

A tightening nut 57 is screwed onto the outer periphery of the end of the pipe 54, and the rubber ring 55 is tightened by screwing the tightening nut 57 forward and backward. 21 is swingably connected. The other three beams 22 are also swingably connected to the retaining plate 21 by the same structure.

The middle and lower unit earth retaining devices 30,
40 is also manufactured in the same structure as the upper unit soil retaining device 20, but the middle unit soil retaining device 30
One iron plate 311 is 3220 mm long and 1000 mm high
In the lower unit retaining device 40, the iron plate 411 of the retaining plate 41 is formed to have a length of 3000 mm and a height of 1000 mm.
In the unit retaining device 40 of the lower stage, the cutting beam 42 is formed to have a length of 470 mm, and the unit retaining device 30 of the middle
Are the retaining plate 21 and the cutting beam 22 of the upper single retaining device 20
The lower unit earthing device 40 can be accommodated from above in the space formed by the earthing plate 31 and the cutting beam 32 of the upper single earthing device 30 in the space formed by. 4 and 5, reference numerals 311 and 411 denote the retaining plates 31, 4 of the unit retaining devices 30 and 40 in the middle and lower stages.
Numerals 1 and 312 and 412 are joint holes.

Further, each of the retaining plates 21, 31, 41
Iron plates 210, 310, 410 and reinforcing bars 211, 3
11 and 411 are lower, middle and upper unit retaining devices 4
The wall thickness is set to be thin in the order of 0, 30, and 20, and the strength against the earth pressure is gradually reduced, for example, so as to be the strength against the earth pressure of the above-mentioned clay mixed with gravel. Further, a medane bolt (suspension hook) 60 is attached to the upper end of each of the retaining plates 21, 31, 41 so that each can be suspended.

Next, a trench excavation method using the earth retaining device 10 of the present embodiment will be described. For example, when burying a sewer pipe in the ground, using a power shovel or the like, a groove having a width and a depth substantially corresponding to the interval and height of the pair of retaining plates 21 of the upper unit retaining apparatus 20 is provided on the ground using a power shovel or the like. After excavation, the upper unit retaining device 20 is suspended from above and installed in the excavated upper wide groove (upper wide groove) from above, and the retaining plates 21 are pressed against the vertical wall surface of the excavated wide groove to secure the retaining. Do.

When the earth retaining by the upper unit earth retaining device 20 is completed in this way, next, the earth and sand below the upper wide groove from the earth retaining plates 21 of the upper unit earth retaining device 20 are removed by a pair of the middle unit earth retaining devices 30. Excavation to a width and depth substantially corresponding to the spacing and height of the earth retaining plates 31, and suspending the middle unit earth retaining device 30 from above and the earth retaining plates 21, 21 and the cutting beams 22, of the upper unit earth retaining device 20 from above. It is installed in the above-excavated middle narrow groove (lower narrow groove) through the space formed by 22.

At this time, the length of the middle retaining plate 31 is shorter than the length of the upper retaining plate 21, and the shorter that portion cannot be retained. Therefore, after the middle retaining device 30 is installed in the middle narrow groove, the angles 313 and 313 are fastened to both sides of the retaining plate 31 with bolts as shown in FIG. The length of the earth retaining can be done. Therefore, nuts are welded to the reinforcing beams 311 on both sides of the retaining plate 31 or screw holes are formed.

Similarly, excavating the lowermost narrow groove below the middle narrow groove, installing the lower unit retaining device 40, and attaching the angles 413, 413 to perform earth retaining, as shown in FIG. As shown, the deep trench can be completely earthed, so that the drain can be safely laid at the bottom of the trench.

After the laying of the sewer pipe is completed, the angle 413 of the lower unit retaining device 40 is removed, and the lower unit retaining device 40 is removed.
Is extruded by its thickness, and the excavated earth and sand or crushed stones carried from other places are backfilled in the lower narrowest groove at a predetermined thickness and compacted. The same operation is repeated, and while the lower unit retaining device 40 is being pulled out, the lower narrowest groove is backfilled. When the lower narrowest groove is backfilled, the lower unit retaining device 40 is completely pulled out, and the lower unit retaining device 40 is completely pulled out on the nearby ground. Put on.

Similarly, the angle 313 is removed from the middle narrow groove and the upper wide groove, and the middle unit soil retaining device 3 is removed.
After the middle narrow width groove is backfilled while pulling out 0, the upper wide groove is backfilled while the upper unit soil retaining device 20 is pulled out.
Excavation work is completed.

[Brief description of the drawings]

FIG. 1 is a view showing a use state of a preferred embodiment of a retaining device according to the present invention.

FIG. 2 is a plan view showing the embodiment.

FIG. 3 is a front view of the upper unit retaining device in the embodiment.
FIG. 3A is a diagram showing a side surface (b) and a plane surface (c).

FIG. 4 is a front view of the middle unit earth retaining device in the embodiment.
FIG. 3A is a diagram showing a side surface (b) and a plane surface (c).

FIG. 5 is a front view of the lower unit earth retaining device in the embodiment.
FIG. 3A is a diagram showing a side surface (b) and a plane surface (c).

FIG. 6 is a diagram showing a connection structure between a cutting beam and a retaining plate in the embodiment.

FIG. 7 is a view showing a conventional earth retaining device.

[Explanation of symbols]

10 soil retaining device 20 upper unit retaining device (upper unit retaining device, first
21 Soil plate 210 Soil plate 210 Iron plate (outer plate) 211 Reinforcement beam 22 Cut beam 30 Middle unit soil retaining device (lower unit soil retaining device, second unit)
31) Soil plate 310 Iron plate (outer plate) 311 Reinforcement beam 32 Cut beam 60 Eyeglass bolt (hanging hook)

Claims (2)

(57) [Claims] 1. A digging trench, wherein at least two unit retaining devices configured in a box system are used by connecting a pair of opposed retaining plates so as to be swingable by left and right cutting beams extending therebetween, and are used in a vertical direction. In the soil retaining device for retaining the ground, the lower unit retaining device is formed to have a dimension that can be inserted from above into a space formed by the retaining plate and the cutting beam of the upper unit retaining device, and the upper and lower unit retaining devices are formed. The device can be used in an unconnected state, and the upper unit retaining device is configured to be weaker against earth pressure than the lower unit retaining device, while the lower unit retaining device is the above on both sides of the earth retaining plate of
The retaining plate of the lower unit retaining device is raised so that the retaining plate of the lower unit retaining device retains the same length as the retaining plate of the upper unit retaining device.
The soil that is shorter than the retaining plate of the unit retaining device above
An earthing device, wherein an angle for fastening is provided by a bolt, and a hook portion for hanging is provided on the earthing plate of each of the unit earthing devices, each of which can be hung. . 2. The method according to claim 1, wherein the retaining plate is a square outer plate.
A reinforcing bar is fixed to one outer edge, and vertical and / or horizontal reinforcing bars are fixed between the reinforcing bars, and the upper unit retaining device thins the outer plate of the retaining plate, or The earth retaining device according to claim 1, wherein the reinforcing bar of the earth retaining plate is configured to be weaker in structure than the lower unit earth retaining device by reducing the thickness, size, or number of the reinforcing bars.