JP7284306B1 - Construction method of underground structure - Google Patents

Abstract

[Problem] To arrange box-shaped roofs having friction cutter plates on the upper surfaces thereof and press-into the ground from the starting pit side to the reaching pit side, leaving the friction cutter plates in the ground while box-shaped roofs and concrete boxes are placed side by side. In the method of constructing an underground structure in which the body is sequentially propelled, even if the friction cut plate is stretched, the influence on the surrounding ground and the like can be suppressed. A friction cut plate installed on the upper side of a box-shaped roof 6 is a first friction cut plate 7a, and a second friction cut plate 7b is superimposed thereon to form first and second friction cut plates 7a and 7b. are fixed by welding or the like and pushed into the ground and installed, and after the box-shaped roof 6 is pushed through, the top portions of the first friction cut plate 7a and the second friction cut plate 7b are welded, etc. to unlock. [Selection drawing] Fig. 1

Description

In particular, the present invention is an underground structure that can be constructed without interfering with upper traffic when constructing a large underground structure in the transverse direction at a shallow position of overburden in the lower underground such as a railway or road. It relates to construction methods of structures.

In order to excavate a large underground structure in a transverse direction into the underground of a railway, a road, etc., it is necessary to have protective work to support the upper traffic, and as such protective work, pipes, such as conventional steel pipes, are horizontally arranged. It is possible to install a roof, etc., but it is safe, reliable, and inexpensive because it is performed at the same time as the underground structure is excavated without having to construct the protection work for the underground structure as a separate construction. In addition, the following construction method is known as one that can be constructed with a shallow earth covering.

As shown in FIG. 8, first, earth retaining steel sheet piles 2 are driven beside upper traffic 1 such as railroads, starting pits 3 and reaching pits 4 are constructed, and a press-fitting machine 5 is installed in the starting pits 3. After installation, the box-shaped roof 6 is pressed into the reaching hole 4. - 特許庁

As shown in FIGS. 10 and 11, the box-shaped roof 6 is a box-shaped tubular body made of steel pipe and having a substantially square cross section. A female joint 6b is formed continuously in the longitudinal direction, and a friction cut plate 7 consisting of a flat plate is attached to the upper surface.

The box-shaped roof 6 is made by press-fitting unit cylinders one by one, and joint flanges 6c for bolt connection are formed at the ends, and the joint flanges 6c are fastened together with bolts and nuts 19 to form a one-piece roof. The required length is buried by adding them one by one in the length direction, and they are arranged side by side while continuing in the lateral direction through the joints 6a and 6b.

Fastening with the bolts and nuts 19 is performed at the end corners of the box-shaped roof 6 as a box opening 6d that opens outward.

The arrangement of the box-shaped roofs 6 is appropriately selected according to the concrete box body 9 to be arranged, such as a straight line shape, a gate shape, a box shape, or the like.

Next, a reaction wall 8 and a concrete box 9 are set in the starting pit 3, a main pushing jack 10 is provided between the reaction wall 8 and the concrete box 9, and a cutting edge is provided at the tip of the concrete box 9. 11 is provided and a small jack 12 is interposed between the tip of the concrete box 9 and the box-shaped roof 6 .

In the figure, reference numeral 13 denotes a support member for the box-shaped roof 6, and 14 a stop member for the friction cut plate 7, which are provided on the side of the starting hole 3, while a pedestal 15 is provided on the side of the landing hole 4.

The small jacks 12 are extended to push forward the box-shaped roofs 6 one by one while leaving the friction cut plates 7 by using the concrete box 9 as a reaction force. , This time, the original pushing jack 10 is extended to excavate the concrete box 9. Reference numeral 16 in the figure denotes a strut interposed between the original pushing jack 10 and the concrete box body 9 .

In this way, the forward movement of the box-shaped roof 6 and the forward movement of the concrete box body 9 are alternately repeated, and the box-shaped roof 6 exposed to the reaching pit 4 is successively removed.

Then, when the tip of the concrete box body 9 reaches the reaching pit 4, the cutting edge 11 and the like are removed, and back-filling grout is appropriately performed to complete the construction.

The following patent document was obtained by the applicant by avoiding the use of a box-shaped roof by using two layers of friction cut plates.
Japanese Patent No. 6510432

In this patent document 1, the friction cut plates are doubled so as to correspond to the outer shape of the box to be propelled, and are assembled into the ground by press-fitting or pulling in a four-sided rectangular arrangement of the lower part, the side part, and the upper part, The outer friction cut plate is fixed, the end of the inner friction cut plate overlaps with the push angle placed in front of the box, and the inner friction cut plate along with the push angle causes friction at the front of the box as the box is propelled. Extrude it with the earth and sand inside the cut plate.

The friction cut plate 7 is a belt-like plate made of steel plate, placed on the box-shaped roof 6 and pressed into the ground together.

Construction method for constructing an underground structure by replacing a box-shaped roof and a box culvert (hereinafter referred to as a box) in the box promotion construction or box traction construction (hereinafter referred to as a box promotion method) as described above. In order to block the influence of the frictional resistance generated on the peripheral surface of the box on the surrounding ground, etc., the friction cut plate 7, which is a thin steel plate, is used to suppress the influence on the surrounding ground and adjacent structures.

The friction cut plate 7 is a steel member peculiar to the construction method described above, which is arranged on the upper surface of the box-shaped roof and the box body to be driven, or on the entire length of the cross section on their peripheral surface.

When the box-shaped roof 6 and the concrete box 9 are propelled, the friction cut plate 7 is fixed to prevent horizontal movement of the ground on the upper surface side or the outer peripheral surface side of the friction cut plate 7. It has been found to have an inhibitory effect.

However, when the box-shaped roof 6 and the concrete box 9 are pushed forward, frictional resistance is generated on the contact surface, and the thickness and length of the member of the friction cut plate 7 and the force acting on the steel member There was an event that the effect of the friction cut plate 7 was reduced due to the elongation caused by the strain of .

In addition, although Patent Document 1 uses a double friction cut plate, it does not prevent the effect of the friction cut plate 7 from being reduced.

An object of the present invention is to eliminate the above-described problems of the conventional example, and to place the box-shaped roofs with friction cut plates on the upper surfaces side by side and press them into the ground from the departure pit side to the arrival pit side, and the friction cut plates are placed in the ground. In the method of constructing an underground structure in which a box-shaped roof and a concrete box are successively pushed forward while being left inside, an underground structure that can suppress the influence on the surrounding ground even if the friction cut plate is stretched. is to provide a construction method of

In order to achieve the above-mentioned object, according to the present invention, box-shaped roofs having friction cut plates on their upper surfaces are arranged side by side and pressed into the ground from the departure hole side to the arrival hole side, and the friction cut plates are installed. In a method of constructing an underground structure in which a box-shaped roof and a concrete box are successively pushed while remaining in the ground, a friction cut plate installed above the box-shaped roof is used as a first friction cut plate, and a second friction cut plate is placed thereon. Friction cut plates are piled up, the tops of the first and second friction cut plates are fixed by welding or the like , and installed by being pushed into the ground, and after the box-shaped roof is pushed through, the first friction cut plate And the fixation such as welding of the top part of the second friction cut plate is released, a return device by a jack is provided behind the concrete box, this return device is connected to the rear end of the first friction cut plate, and the concrete box The gist of the present invention is to measure the displacement of the first friction cut plate pulled together with the propulsion of the plate, and pull it back by the return device when it exceeds a set range.

According to the present invention of claim 1, by stacking the second friction cut plate on the first friction cut plate, the first friction cut plate is used when the box-shaped roof and the concrete box are pushed forward. Even if elongation occurs, such elongation does not occur in the second friction cut plate, and the influence on the surrounding ground or the like can be suppressed by the second friction cut plate.

In addition, the first friction cut plate is pulled together with the box-shaped roof and the concrete box, and the part that is displaced forward due to this extension is corrected by pulling the rear end backward with the return device. .

The present invention of claim 2 is characterized in that the tip of the second friction cut plate is fixed to the reaching hole.

According to the second aspect of the present invention, by fixing the tip of the second friction cut plate to the reaching hole, it is possible to make the second friction cut plate less susceptible to the displacement of the first friction cut plate. It is possible to reliably suppress the influence of the propulsion of the roof and concrete box on the surrounding ground.

As described above, according to the construction method of the underground structure of the present invention, box-shaped roofs having friction cut plates on their upper surfaces are arranged side by side and pressed into the ground from the departure pit side to the arrival pit side, and the friction cut plates are placed side by side. In the construction method of the underground structure in which the box-shaped roof and the concrete box are successively pushed forward while leaving the ground in the ground, even if the friction cut plate stretches, the influence on the surrounding ground etc. can be suppressed. is.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal side view which shows 1st Embodiment of the construction method of the underground structure of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal front view which shows 1st Embodiment of the construction method of the underground structure of this invention. FIG. 4 is a longitudinal side view showing a second embodiment of the method for constructing an underground structure according to the present invention; FIG. 2 is a longitudinal front view showing a second embodiment of the method for constructing an underground structure according to the present invention; FIG. 4 is an explanatory diagram showing a step of friction cut plate control in the method of constructing an underground structure according to the present invention; 4 is a flow chart of friction cut plate control in the underground structure construction method of the present invention. FIG. 4 is an explanatory diagram of friction cut plate control in the underground structure construction method of the present invention; It is a side view of the first half process which shows the outline of the construction method of an underground structure. It is a side view of the latter half process which shows the outline of the construction method of an underground structure. 1 is a perspective view of a box roof; FIG. 1 is a front view of a box roof; FIG.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical cross-sectional side view showing a first embodiment of the method for constructing an underground structure according to the present invention, and FIG. 2 is a vertical cross-sectional front view of the same. The method of constructing an underground structure is described in FIG. , as described in FIG.

The box-shaped roof 6 may be propelled by interposing the small jack 12 between the tip of the concrete box 9 and the box-shaped roof 6 as described above. It is also possible to push out the box-shaped roof 6 as a whole by pushing the concrete box body 9.

Further, in the illustrated embodiment, the box-shaped roof 6 is arranged in a gate shape on the concrete box body 9 .

In the present invention, the friction cut plate installed on the upper side of the box-shaped roof 6 is the first friction cut plate 7a, and the second friction cut plate 7b is superimposed thereon to form the first and second friction cut plates 7a and 7b. Fix the top of each by welding, etc., and propel it into the ground to install.

The friction cut plates 7a and 7b are made of flat steel plates, and the box-shaped roof 6 is press-fitted one by one. Box-out joint flanges are formed at the ends, and the joint flanges are fastened with bolts and nuts. Therefore, when burying the necessary length by adding one piece at a time in the length direction, only the upper surface of the box-shaped roof 6 is overlapped except for the tip. , these friction cut plates 7a and 7b are also lengthened by connecting them by welding or the like by the length of the box-shaped roof 6. As shown in FIG.

Besides welding, bolts and nuts can also be used as a means for fixing the top portions of the first and second friction cut plates 7a and 7b to the box-shaped roof 6, respectively.

A lubricant may be inserted between the first and second friction cut plates 7a and 7b.

After the box-shaped roof 6 is propelled through, the fixation such as welding of the top portions of the first friction cut plate 7a and the second friction cut plate 7b is released.

The tip of the second friction cut plate 7b is fixed to the strut 22 provided in the reaching hole 4 by welding or the like, and the rear end is fixed to the starting hole 3 as required. The tip of the second friction cut plate 7b may be fixed to the earth retaining steel sheet pile 2 (see FIG. 8) of the reaching hole 4 without providing the strut 22.

A return device with a pull-back jack 23 was provided behind the concrete box 9, and the pull-back jack 23 was connected to the rear end of the first friction cut plate 7a via a pull-back member 24.

The tip of the first friction cut plate 7a is left free without being fixed on the reaching hole 4 side.

A tie rod made of a PC steel bar can be used as the pull-back member 24, and a fixture is provided at the rear end of the friction cut plate 7a to connect the fixture and the jack.

For example, it is possible to use a center hole type jack or a screw type jack for the pull-back jack 23, or use a string member such as a wire or a PC steel wire instead of the tie rod.

In this way, the box-shaped roof 6 and the concrete box 9 are advanced while leaving the friction cut plates 7a and 7b. If so, the pull-back jack 23 is controlled as shown in FIG. The amount of pullback of the pullback jack 23 is adjusted by controlling (using an electric resistor) the amount of oil discharged from the hydraulic pump that operates the hydraulic jack.

FIG. 7 is an explanatory diagram of the control setting range, and the control setting range defines the primary set value and the secondary set value with respect to the origin position.

FIG. 5(a) shows the state of the box-shaped roof 6 and the concrete box 9 before propulsion, and the pull-back jack 23 always maintains a low pressure and a pulling force. The friction cut plate 7b is in a state of being prevented from horizontal movement.

When the box-shaped roof 6 or the concrete box 9 is propelled, if the friction cut plate 7a exceeds the control range of the measurement origin (a), it is instantly pulled back with high pressure.

FIG. 5(b) shows a state in which the box-shaped roof 6 or the concrete box 9 is pushed forward by one stroke, and the pull-back jack 23 is operating at a low pressure. Frictional resistance (a) is generated, but the friction cut plate 7a is not displaced.

FIG. 5(c) shows a state in which the friction cut plate 7b prevents horizontal movement, the concrete box 9 and the box-shaped roof 6 are advanced by one stroke, and the pull-back jack 23 is operated at a low pressure. A displacement amount (a) is generated due to the generation of the frictional resistance (a), and a situation is shown in which the displacement amount (b) is generated together with the frictional resistance (a). The amount of displacement (b) includes the amount of elongation of the FC plate member. The friction cut plate 7b does not move horizontally and maintains the measurement origin (b).

FIG. 5(d) shows a state in which the friction cut plate 7b has pulled back the friction cut plate 7a by switching the pull-back jack 23 of FIG. 5(c) to a high pressure.

When the friction cut plate 7a returns to the predetermined position, the pull-back jack 23 is switched (returned) to a low pressure. The friction cut plate 7b does not move horizontally and maintains the measurement origin (b).

FIG. 6 shows the control flow.

3 and 4 show a second embodiment of the present invention, in which a box-shaped roof 6 is arranged in a box shape on a concrete box 9, and the friction cut plates 7a and 7b are also attached to the box-shaped roof 6. They are arranged in a box shape on the outside.

A box-shaped roof 6 is assembled and arranged so as to correspond to the outer shape of the concrete box 9 to be propelled, and after it is pressed into the ground from the starting pit 3, the concrete box 9 is attached to the end of the box-shaped roof 6. By arranging the tip part, the earth and sand in the face part can be pushed out to the reaching pit 4 side together with the box-shaped roof 6 as the concrete box body 9 is propelled.

REFERENCE SIGNS LIST 1 Upper transportation 2 Earth retaining steel sheet pile 3 Departure pit 4 Reach pit 5 Press-in machine 6 Box roof 6a, 6b Joint 6c Joint flange 6d Box drawer 7, 7a, 7b Friction cut plate 8 Reaction wall 9 Concrete box 10 Main pushing jack 11 Cutting edge 12 Small jack 13 Supporting material 14 Stopping member 15 Receptacle 16 Strut 17 Main body 19 Bolt, nut 20 Backing plate 21 ... bolt 22 ... strut 23 ... withdrawal jack 24 ... withdrawal member

Claims (2)

Box-shaped roofs with friction-cut plates on their upper surfaces are placed side by side and pressed into the ground from the starting pit side to the arrival pit side, and the box-shaped roofs and concrete boxes are successively placed while leaving the friction-cut plates in the ground. In the construction method of the underground structure to be propelled, the friction cut plate installed on the upper side of the box-shaped roof is used as the first friction cut plate, and the second friction cut plate is superimposed thereon to form the first and second friction cut plates. The top parts of each are fixed by welding, etc., and installed by pushing them into the ground. Released, a return device with a jack is provided at the rear of the concrete box, this return device is connected to the rear end of the first friction cut plate, and the first friction cut plate pulled together as the concrete box is propelled. A method for constructing an underground structure, characterized in that when displacement is measured and exceeds a set range, the return device is used to return the displacement . 2. The method of constructing an underground structure according to claim 1, wherein the tip of the second friction cut plate is fixed to the reaching hole.

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