JPH0776842A - Cut and cover tunneling method and earth retaining device for the method - Google Patents

Abstract

PURPOSE:To easily cut a ditch in a soft ground, by placing a box type earth retaining device in the shallow ditch without supports and pushing down it and excavating the soil between the earth retaining plates and removing it. CONSTITUTION:A pair of oppositely arranged earth retaining plates 10, 10 are supported by struts 18, 18 to keep the counter gap and the posture and connected to each other so as to be vertically movable and form a box type earth retaining device 1. And the earth retaining device 1 is placed in a supportless shallow ditch having a necessary but minimum width. Next, the nearly middle part of the upper side of both earth retaining plates 10 are alternately pushed down within the allowable sliding distance of the struts 18 while keeping the counter gap and the posture. And sand and soil between the earth retaining plates 10 are excavated and removed. And these works are repeated to cut a ditch while retaining the earth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a simple work in a short working time when the ground is soft in various burial works for water and sewer pipes, agricultural and industrial water pipes, gas pipes, electric installation pipes and other excavation work. TECHNICAL FIELD The present invention relates to an excavation method capable of performing excavation by performing soil retention and preventing water leakage, and a soil retention device used therefor. For convenience of description, sewer construction will be described below as an example.

[0002]

2. Description of the Related Art For example, when sewage pipes are to be buried in sewer construction, the open-cut method is widely used. However, when sewage pipes are to be buried at a depth of 1.5 m or 2 m underground, Since there is concern about collapse, it is common to retain soil to ensure workability and safety.

In this soil retaining device, as shown in FIGS. 5 (a) and 5 (c), a pair of soil retaining plates 90 are opposed to each other and joints 92 are provided on the inner surfaces of both sides thereof.
A box method is known in which the two are mutually connected by a cross beam 91 (see Japanese Utility Model Publication No. 58-47101, etc.).

When retaining soil with the above-mentioned device, a backhoe or the like is used to excavate a raised groove on the soil wall of a width required for the ground to a desired depth, and the soil retaining device is lifted by a crane or the like into the excavated groove. A construction method is employed in which the soil is installed, the length of the girder is adjusted, and the soil retaining plate 90 is pressed against the outer soil wall surface to retain the soil.

[0005]

However, when the ground is soft, such as sandy soil, the soil wall surface is likely to collapse, and a steep soil wall surface cannot be formed. However, depending on the construction environment, there were cases where the groove width was limited and the necessary wide groove could not be excavated.

Therefore, for a soft ground, a shallow trench is dug, a soil retaining device is installed there, and the soil retaining plates are alternately pushed into the ground while excavating the earth and sand between the soil retaining plates with a backhoe or the like. Then, it is suggested to open and cut the groove.

However, the conventional box type soil retaining device is manufactured in consideration of construction on a relatively hard ground, and the joints 92 at both ends of the beam girder 91 interpose a rubber bush 920 as shown in FIG. 5 (c). Since it is configured to swing,
When one soil retaining plate 90 is pushed deeply at a time, the cutting beam 91 is centered on the other soil retaining plate 90 side joint 92.
Due to the rocking of the earth retaining plate 90, the distance between the soil retaining plates 90 is gradually narrowed and the above method cannot be adopted.
As shown in FIG.
It is necessary to sequentially push in the four corners of the soil retaining plate 90 by about m, as indicated by arrows ~, which causes a problem that the work is complicated and the work time is long.

At the construction site, a plurality of soil retaining devices are arranged in the longitudinal direction to retain the soil. When the soil retaining plate 90 is pushed into the excavation groove while swinging left and right as described above, a gap is generated between the adjacent soil retaining plates 90. Is likely to occur and there is a concern that water will leak into the trench.

In view of the above problems, the present invention provides an excavation method and an earth retention device used therefor capable of excavating soil on a soft ground with a simple operation and a short operation time while constructing an earth retention, and further eliminating the concern of water leakage. The challenge is to provide.

[0010]

Therefore, in the excavation method according to the present invention, a trench is excavated in the ground, and a soil wall surface of the excavated trench is formed by a box-type soil retaining device in which a pair of opposing soil retaining plates are connected by a cutting beam. When retaining soil, use a device that enables the soil retaining plates to move in parallel in the vertical direction while maintaining the facing interval and posture with each other. Excavate the earth and install the soil retention device,
The soil retaining is performed by pushing the soil retaining plates in the approximate center of the upper side of the soil retaining plates alternately in parallel to each other while keeping the facing distance of each of the cross beams by parallel with each other and the soil retaining plates of the adjacent soil retaining devices. It is characterized in that the earth and sand between the plates are excavated and discharged, and the earth retention and excavation are repeated to open and cut the groove.

Further, the soil retaining device according to the present invention is a box type soil retaining device in which a pair of opposing soil retaining plates are connected by a crossbeam, and slide guides are provided near both sides of both soil retaining plates and extend vertically. A slide member is supported in the slide guide, and a slide groove having a predetermined length is formed to extend in the up-down direction on the opposite surface of the slide guide, and the end portion of the cut beam is attached to the slide member through the slide groove. It is fixed so that the soil retaining plate can be slid vertically by the length of the slide groove, while the soil retaining plates are guided by a slide member so that they can move in parallel while maintaining the facing interval and posture. To do.

The shape of the slide guide is not particularly limited, but a tubular shape such as a square tubular shape or a cylindrical shape is preferable. in this case,
The earth retaining plate may be used to form a tubular shape. The slide member may guide the soil retaining plates so that they can be moved in parallel while maintaining the facing interval and posture, for example, the slide member can be slidably contacted with at least the outer and inner side portions of the slide guide. The cross-sectional shape may be a shape having a predetermined length continuous in the vertical direction. If the slide guide has a square tubular shape, the slide member is U-shaped or H-shaped.
It may have a cross-sectional shape including a shape, or it may be a square tube shape so as to make sliding contact with almost the entire inner surface of the reinforcing column, and if the slide guide is a cylindrical shape, an outer circular arc and both side circular arcs. The cross section may be an arcuate section that can be slidably contacted with the maximum diameter portion of The slide guide can also be used as a reinforcing column of the soil retaining plate, but it may be provided separately. The cut beam may be made to have a constant length by using a shape steel or the like, but a reverse screw may be cut in the middle of the rod so that the length can be adjusted by a joint. Further, one cut beam may be provided for each of the left and right slide guides, but in consideration of earth pressure resistance, a plurality of cut beams may be provided at a predetermined interval in the vertical direction. That is, it is preferable to form a plurality of slide grooves on each slide guide at predetermined intervals in the vertical direction, and fix the end portion of the girder to the slide member in the slide guide via each slide groove. in this case,
The slide member in the slide guide may be one or plural. Further, in consideration of water leakage prevention when the soil retaining devices are installed side by side, an engaging member such as a C channel is provided on the outer surface of the slide guide so as to extend in the up-down direction so that the engaging members of the adjacent soil retaining devices are interlocked with each other. It is good to be able to match.

[0013]

[Operation and effect of the invention] A box type soil retaining device is installed by digging a shallow groove with a minimum required width in the ground with a backhoe, and earth and sand between the soil retaining plates of the device are excavated with a backhoe, etc. In addition, if you push the lower center of both soil retaining plates alternately downward with a bucket of a backhoe, etc., the soil retaining plates will maintain their facing interval and will be parallel downward by the sliding allowable distance of the cutting beam while maintaining their installation posture. By moving and repeating such work, it is possible to efficiently excavate the groove with the minimum necessary width while retaining soil.

Therefore, even when the ground is soft, it is not necessary to excavate a wide wide groove as in the conventional case, and the complicated work of alternately pushing each of the four corners of the soil retaining plate is unnecessary, and the cutting Since it can be pushed in by the slide allowable distance of the beam, it is possible to open and excavate while surely retaining soil with a simple work in a short working time.

Further, since the soil retaining plates are kept in the installed posture, that is, they are pushed downward in parallel with the soil retaining plates of the adjacent soil retaining devices, even if the soil retaining devices are installed side by side, there is no gap between the soil retaining plates, and there is a risk of water leakage. Can be resolved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the specific examples shown in the drawings. 1 and 2 show a soil retaining device according to an embodiment of the present invention. In the figure, the earth retaining device 1 is configured by connecting a pair of opposed earth retaining plates 10 to each other with a cross beam 18. The earth retaining plate 10 is made of an iron plate, and the inner side of the earth retaining plate 10 has rectangular cylindrical reinforcing columns 11 which are vertically welded on both sides thereof and are welded together.
Between the reinforcing columns 11, three horizontal beams 12 and one vertical column 1
3 are welded, and reinforcing ribs 14 are welded between them at an appropriate interval.

A hook 15 is attached to the upper end of each reinforcing column 11, and a biting claw 19 is detachably inserted into the lower end of the reinforcing column 11. A band plate made of hardened steel is preferably welded to the lower edge of the clasp plate 10 in consideration of wear.

A slide groove 16 having a predetermined length is formed in the upper portion of the opposing surface of the reinforcing column 11 so as to extend in the vertical direction, and the inside of the reinforcing column 11 has an outer shape substantially equal to the inner surface shape of the reinforcing column 11. A slide member 17 having a predetermined length and capable of sliding contact with the inner surface of the reinforcing column 11 is housed. On the other hand, the cut beam 18 has two screws with an internal thread on the inner part, and a joint with an internal thread on the inner surface is screwed into the inner part of the rod to be connected to adjust the length. Both ends of the cutting beam 18 are inserted into the slide grooves 16 of the reinforcing column 11 to reinforce the supporting column 1.
It is fixed to the slide member 17 in 1. The fixing method may be welding or may be fixing with bolts and nuts.

Next, the excavation method will be described with reference to FIGS. 3 and 4. For example, when burying a sewer pipe, first, as shown in FIG. 3 (a), a shallow groove D having a minimum required width is dug in the ground E, and the joint of the beam girder 18 of the earth retaining device 1 is turned to extend the length. The height of the soil retaining device 1 is lifted using a crane, a backhoe 2, etc., and the soil retaining device 1 is installed in a trench D, which is dug as shown in FIG. 3 (b).
1 Soil retention device 1 by letting the biting claw 19 at the bottom end bite into the ground
Firmly fix. Next, as shown in FIG. 3 (c), the soil between the soil retaining plates 10 of the soil retaining device 1 is excavated by the bock hoe 2 to remove the soil, and the bucket of the back hoe 2 is used to remove the soil as shown in FIG. 3 (d). The center of the upper side of the soil retaining plate 10 is alternately pressed downward (see arrows in FIGS. 3 and 4).

At this time, both ends of the cut beam 18 are fixed to a slide member 17 having a predetermined length capable of sliding contact with the entire inner surface of the reinforcing column 11, and the cut beam 18 connects the two soil retaining plates 10 to each other. When one soil retaining plate 10 is pressed downward, the other soil retaining plate 10 is pressed as shown in FIG.
And the girder 18 is in the original installation state G, and the one soil retaining plate 10 is in the same state as the one-dot chain line E, that is, the vertical length of the slide groove 16 (see FIG. 2) while maintaining the facing interval and the installation posture. (See A), for example, it is translated downward by 30 cm and pushed into the state shown by the solid line F, and the other soil retaining plate 10 can also be translated downward by the length of the slide groove 16 as indicated by the chain line H. . By repeating such work, it is possible to efficiently excavate the groove with the minimum necessary width while retaining soil, and similarly install the soil retaining device 1 on the continuous ground to excavate the next groove, Bring in the sewer pipe, pour concrete into it, and retain the soil 1
You can pull up and refill the earth and sand.

Therefore, even when the ground is soft, it is not necessary to excavate a wide wide groove as in the conventional case, and the complicated work of alternately pushing the four corners of the soil retaining plate 10 is not required, and Since the soil retaining plate 10 can be pushed in at one time by the length of the slide groove 16, it is possible to perform excavation while retaining soil with certainty in a simple work and in a short working time.

Further, since the soil retaining plates 10 are pushed downward in parallel in the installed posture, even if the soil retaining devices 1 are installed side by side, the outer surfaces of the reinforcing columns 11 of the adjacent soil retaining plates 10 can be brought into close contact with each other, and between them. There are no gaps, and the concern about water leakage can be eliminated.

When excavating a deep groove, the earth retaining device 1 may be stacked above the pushed earth retaining device 1, or the earth retaining device 1 may be overlapped and connected in advance. At this time, the reinforcing columns 11 of the upper and lower soil retaining devices 1 may be connected by a connecting member, but the biting claw 19 of the upper soil retaining device 1 is inserted into the upper end opening of the reinforcing column 11 of the lower soil retaining device 1 and is bolted. It is also possible to fix and connect to the reinforcing column 11 by means such as.

The left and right soil retaining plates 10 are reinforcement columns 1.
The cutting beam 18 is fixed to the slide member 17 having the same shape as that of 1 and capable of sliding contact with the inner surface, and the upper portions of the soil retaining plates 10 are connected to each other. It can withstand pressure sufficiently. In addition,
When the earth pressure is high, the lower part of the earth retaining plate 10 may be slidably connected to the upper and lower sides by the beam 18.

In the soil retaining device 1 of this embodiment, the girder 1
Since the length of 8 can be adjusted, when the ground is hard, the construction method similar to that of the conventional device, that is, excavating a steep groove on the soil wall surface and installing it, the soil retaining plate 10 is expanded outward to retain the soil. It can also be used in the construction method. In addition, excavate a steep groove of a desired width on the soil wall surface,
It is also possible to press down alternately on the outer wall surface of the soil or shave it, and alternately push downward to perform soil retention.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an earth retaining device according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the soil retaining device.

FIG. 3 is a process drawing showing an excavation method according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the soil retaining device.

FIG. 5 is a diagram for explaining a conventional soil retaining device.

[Explanation of symbols]

 1 Soil retaining device 10 Soil retaining plate 11 Reinforcing column 16 Sliding groove 17 Sliding member 18 Cut beam E Ground D Shallow groove

Claims (5)

[Claims] 1. When retaining a soil wall surface of an excavation trench with a box-type soil retaining device in which a groove is excavated in the ground and a pair of opposing soil retaining plates are connected by a crossbeam, the soil retaining plates are opposed to each other at an interval and Using a device configured to be able to move in parallel in the vertical direction while maintaining the posture, excavate the shallow groove with the minimum necessary groove width to be excavated in the ground, install the soil retaining device, and install both soil retaining plates. The upper center of the upper side is pushed parallel to each other and parallel to the adjacent soil retaining plate of the adjacent soil retaining device while maintaining the facing interval by the sliding allowable distance of the cross beam, and the soil retaining is performed while the soil retaining plates are retained. An excavation method characterized by excavating earth and sand, discharging the soil, and excavating the groove by repeating the soil retention and excavation. 2. A box-type soil retaining device in which a pair of opposing soil retaining plates are connected by a crossbeam, and slide guides are provided in the vicinity of both sides of the both soil retaining plates so as to extend in the vertical direction, and slide inside the slide guides. The member is supported, and a slide groove having a predetermined length is formed on the opposite surface of the slide guide so as to extend in the vertical direction, and the end portion of the girder is fixed to the slide member through the slide groove to fix the earth retaining plate. While the slide member is slidable in the vertical direction by the length of the slide groove, the soil retaining plate is guided by the slide member so that the soil retaining plates can be translated in parallel while maintaining the facing interval and posture. . 3. The slide guide has a cylindrical shape, and the slide member has a cross-sectional shape capable of sliding contact with at least outer and inner side portions of both sides of the slide guide, the cross-sectional shape being continuous for a predetermined length in the vertical direction. Item 2. The soil retaining device according to item 2. 4. A rectangular tubular reinforcing column is provided on both sides of the soil retaining plate to serve as the slide guide, and the slide member has an outer shape substantially equal to the inner surface of the reinforcing column and slides on substantially the entire inner surface of the reinforcing column. The earth retaining device according to claim 3, which is brought into contact with the earth retaining device. 5. The slide groove according to claim 2, wherein a plurality of the slide grooves are formed at a predetermined interval in the vertical direction, and the ends of the plurality of cut beams are fixed to the slide member via the slide grooves. The soil retaining device according to any one.