JP5787315B2 - Precast retaining wall propulsion method - Google Patents

Description

  The present invention relates to a technique for constructing a retaining wall by a propulsion method.

  Patent Document 1 discloses a technique for constructing a retaining wall by an open shield method. In this technology, an L-shaped block is suspended behind the open shield machine equipped with a propulsion jack, and the earth and sand in front of the open shield machine is excavated and removed. The open shield machine is moved forward with the reaction wall as the reaction wall, and the next L block is suspended vertically between the propelled jack and the L block, and the open shield machine is advanced and the L block is added. It is characterized by repeating to a predetermined arrival position, and then removing the upper L-shaped block, and the construction period can be shortened compared with the conventional method of building a mold and placing and curing concrete. It is.

Incidentally, the technique described in Patent Document 1 has the following problems.
A) As the open shield machine moves forward, the excavation backhoe, the dump truck for carrying out the earth and sand, and the crane for lifting the block are moved. Yes.
B) Since the face is opened, ground improvement work is required for grounds with high groundwater levels and grounds with high collapse.
C) In order to construct an L-shaped retaining wall, a reverse L-shaped block that is not required after construction is used, and after the retaining wall is constructed, a gutter that becomes a waterway is constructed separately, so there are many work processes and construction costs are low. The height is high, and the width of the road is narrower as the gutters are constructed.
D) After the construction of the retaining wall, the backfill injection process for filling the gap between the L-shaped block and the natural ground is performed separately, so that the number of work steps is increased.
E) Although a steel pipe is driven from the ground surface into the through-hole opened in the L-shaped block to prevent the retaining wall from slipping, the adhesion with the natural ground is poor and the effect is insufficient.
F) The L-shaped blocks are tightly connected only to the front and rear joints, and the earthquake resistance is insufficient.

Japanese Patent No. 3766423

  The problem to be solved by the present invention is to solve these conventional problems, without requiring a large work area for temporary construction, and to construct the retaining wall and waterway in one step regardless of the current state of natural ground It is to provide a precast retaining wall propulsion method that can be saved and cost-effective.

The configuration of the present invention that solves this problem is as follows.
1) to construct a digging to starting pit part of the ground of slopes along slopes and road trying to build a retaining wall, comprising a water channel within the rear end of the shield tunneling machine capable of excavating the substantially trapezoidal cross section A trapezoidal retaining wall block with a sloping vertical road side is connected at the start shaft, and the retaining wall block is pushed with the main pusher installed at the start shaft, and the excavated soil is dug while excavating the ground Take it into the aircraft and discharge it backward through the retaining wall block water channel, connect the next retaining wall block behind the retaining wall block, repeat the excavation of the excavator and the addition of the retaining wall block until it reaches a predetermined arrival position, These retaining wall blocks are watertightly connected with a stainless steel or steel collar to form retaining walls and water channels, and then the roadside soil on the retaining wall blocks is removed. Wall propulsion method 2) During excavation Precast retaining wall propulsion as described in 1) above, in which a solidified lubricant is simultaneously filled into the gap between the retaining wall block and the natural ground from the beginning, and backfilling is carried out into the gap after the propulsion is completed. Method 3) After embedding the retaining wall block in the ground, drilling the ground from the bottom of the water channel inside the retaining wall block, inserting rebar into the drilling hole, filling concrete, and forming the cast-in-place foundation pile The precast retaining wall propulsion method described in 1) or 2) 4) A retaining wall block in which a hole into which a steel bar can be inserted is formed along the water channel is used. The precast retaining wall propulsion method 5) described in any one of 1) to 3) above, which is tightened for integration by connecting steel bars, and used for the precast retaining wall propulsion method described in any one of 1) to 4) above machine is trapezoidal road side are inclined in the longitudinal length Attach a bulkhead with an earth opening to the front end of the outer shell, attach a plurality of motors with speed reducers in a row on the inner surface of the bulkhead, make the output shaft protrude forward of the bulkhead, and output shafts of the upper motors A rotating cutter that rotates in the shape of a wheel via a bevel gear is attached to the bottom motor, a cross-shaped spoke cutter is attached to the bottom motor, and a soil removal device is connected to the soil discharge port and attached in the outer shell. There is a precast retaining wall propulsion method.

  According to the configuration described in the above 1) of the present invention, the necessary work area is only the start shaft, its surroundings, and the reaching shaft that collects the excavator, and the excavated sediment is excavated by the mud drainage, the belt conveyor and the tro bucket. Since the soil is discharged through the interior and the retaining channel block, there is no need for backhoes, dump trucks, temporary landings or temporary roads for them. In addition, since the face is excavated in a closed type, ground improvement work is not required even in the ground where the groundwater level is high or the ground where the collapse is high. Furthermore, since the retaining wall block is provided with a water channel, the retaining wall work and the water channel work are completed in one process, and the width of the road can be widened because no side groove is constructed.

  According to the configuration described in the above 2) of the present invention, the ground type filling and the friction cut are simultaneously performed while injecting the consolidated type lubricant in parallel with the excavation, and the back-injection is performed after reaching the conventional technique. The work process can be reduced in comparison.

  According to the configuration described in 3) of the present invention, the concrete foundation pile is a cast-in-place pile, and therefore has good adhesion to the ground, and a method of using a conventional steel pipe, PC pile, or RC pile. Compared with the natural ground, the effect of integration (adhesion) with the natural ground and the prevention of natural ground slip are high.

  According to the configuration described in 4) of the present invention, since the retaining wall block from the start to the end is integrated with the long steel bar after the completion of the propulsion, the seismic resistance is improved as compared with the conventional brazing joint. It will be excellent.

It is a front view of the excavation machine of an Example. It is sectional drawing of the excavation machine of an Example. It is sectional drawing of the retaining wall block of an Example. It is explanatory drawing which shows excavation of an Example. It is sectional drawing of the retaining wall constructed | assembled of the Example. It is the side view seen from the road side of the retaining wall in which the Example was constructed.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be specifically described based on examples and drawings.

  1 is a front view of the excavator of the embodiment, FIG. 2 is a cross-sectional view of the excavator of the embodiment, FIG. 3 is a cross-sectional view of the retaining wall block of the embodiment, and FIG. 4 is an explanatory view showing the excavation of the embodiment 5 is a cross-sectional view of the retaining wall constructed according to the embodiment, and FIG. 6 is a side view of the retaining wall constructed according to the embodiment as viewed from the road side.

  In the figure, 10 is an excavator, 11 is an outer shell, 12 is a bulkhead, 12a is a discharge port, 13 is a motor, 13a is an output shaft, 14 is a rotary cutter, 14a is a bevel gear, 14b is a transmission shaft, and 14c is a protection Cover, 15 is a spoke cutter, 16 is a soil removal device, 17 is a mud discharge conveyor, 20 is a retaining wall block, 21 is a water channel, 22 is an insertion pipe, 23 is a drain pipe, 24 is a drain pipe, and 25 is a box punching section. , 26 stuffing, 30 starting shaft, 31 main pushing device, 32 starting frame, 40 bar steel, 41 tightening nut, 50 reinforcing bar, 51 concrete, C is cast-in-place pile, G is ground , R is a road.

  As shown in FIGS. 1 and 2, the excavator 10 according to the present embodiment has a soil discharge port 12 a opened at the front end of a trapezoidal outer shell 11 that is slightly vertically long, inclined on the road R side, and vertical on the natural ground G side. The partition wall 12 is attached, and four motors 13 with speed reducers are attached in a column on the inner surface of the partition wall 12 so that the output shaft 13 a protrudes in front of the partition wall 12. The output shafts 13a of the upper three motors 13 are meshed with a transmission shaft 14b by a bevel gear 14a and arranged at a right angle, and a rotary cutter 14 that rotates like a wheel is attached to the transmission shaft 14b. A cross-shaped spoke cutter 15 is attached to the motor 13. A soil removal device 16 is connected to the soil discharge port 12 a and attached to the outer shell 11.

  As shown in FIG. 3, the retaining wall block 20 is made of precast concrete having a vertically long, trapezoidal shape in which the road R side is inclined and the natural ground G side is vertical and has a length of 1 to 1.5 m. A water passage 21 having a trapezoidal cross section is penetrated in the longitudinal direction, and four insertion pipes 22 made of vinyl chloride resin are embedded in the longitudinal direction in the upper part. A drain pipe 23 made of vinyl chloride resin is buried on the slope side of the water channel 21, and a drain pipe 24 made of vinyl chloride resin is buried on the vertical surface side of the water channel 21. The drain pipe 23 and the drain pipe 24 are closed from the inside with a rubber filling 26 so that earth and sand do not flow into the water channel 21 during construction. Alternatively, instead of the drainage pipe 23 and the drainage pipe 24, a hole for drainage and drainage is recessed halfway so that earth and sand do not flow into the water channel 21 during the construction, and the hole is penetrated from the inside after the construction. It is good also as a drainage channel and a drainage channel. The drain pipe 23 is for guiding rain water on the road R to the water channel 21, and the drain pipe 24 is for guiding water in the natural ground G to the water channel 21. At the bottom of the water channel 21, a box extraction part 25 for constructing the cast-in-place foundation pile C is provided in advance. The bottom of the box extraction part 25 is thinned so that it can be easily penetrated when drilling. The box extraction portions 25 are provided at a pitch of about 1.5 m on the extension line, and if the length of the retaining wall block 20 is 1.5 m, there is one box per unit. A stainless steel or steel collar (not shown) for watertightly connecting the front and rear retaining wall blocks 20 is provided at either the front or rear end of the retaining wall block 20.

  In this embodiment, as shown in FIG. 4, a part of the slope where the retaining wall is to be constructed is excavated to construct a start shaft 30 and a reaching shaft (not shown), and a main pushing device is provided on the start shaft 30. 31 and the starting stand 32 are suspended by a crane or the like. The excavator 10 is suspended from the starter base 32 and the retaining wall block 20 is suspended and connected to the rear end of the excavator 10. In the water channel 21 of the retaining wall block 20, a waste mud conveyor 17 is disposed from the lower part of the soil removal device 16 to the start shaft 30.

  When the motor 13 is operated to rotate the rotary cutter 14 and the spoke cutter 15 and the retaining wall block 20 is pushed by the main pushing device 31 to advance the excavator 10 into the ground, the natural ground G has a substantially trapezoidal cross section. While being excavated, the excavated earth and sand is taken into the earth removing device 16 from the earth discharge port 12a and conveyed by the mud conveyor 17 in the water channel 21 of the retaining wall block 20, and lifted by a bucket truck or vacuum type mud absorbing earth It is discharged out of the mine with a device. At the same time, a solid lubricant is simultaneously injected from a grout cock (not shown), and the gap between the retaining wall block 20 and the natural ground G is filled. Thereafter, the back-filling work is performed, so that the work process is reduced as compared with the prior art.

  When the retaining wall block 20 is embedded in the natural ground G, the main pushing device 31 is contracted, and the next retaining wall block 20 is suspended so that the water channel 21 communicates with the rear end of the preceding retaining wall block 20. Then, in the same manner as described above, the main pushing device 31 pushes and excavates, and the excavation of the excavating machine 10 and the addition of the retaining wall block 20 are repeated until the reaching shaft is reached. In this way, the excavation work is performed only in the natural ground G, so that there is no need for backhoes, dump trucks, temporary landings or temporary roads for them as in the prior art, and traffic congestion occurs on the road R. There is no. Moreover, since the face is excavated in a closed type, ground improvement work can be omitted even when the groundwater level is high or the collapse property is high.

  When all the retaining wall blocks 20 are buried in the ground, the long PC bar 40 is communicated with the insertion tube 22 of the retaining wall block 20 from the start to the arrival, and both ends thereof are tightened with the tightening nuts 41. Each retaining wall block 20 is integrated by this PC bar 40, and is excellent in earthquake resistance as compared with a conventional bead joint. In addition, a natural ground G is drilled through the bottom of the box extraction part 25 of each retaining wall block 20, a reinforcing bar 50 is arranged in the drilled hole, and concrete 51 is injected to form a cast-in-place foundation pile C. To do. Since the cast-in-place foundation pile C is made of concrete having good adhesion to the natural ground G, it has a higher anti-slip effect than a method using a conventional steel pipe or the like. Further, the gap between the water channels 21 is filled with mortar or the like for watertight treatment, and the filling 26 is removed from the drain pipe 23 and the drain pipe 24 and collected.

  Thereafter, the top soil on the road R side on each retaining wall block 20 is removed to expose the block surface, and the starting shaft 30 and the reaching shaft are backfilled to complete the construction (see FIGS. 5 and 6). As described above, since the retaining wall work and the water channel work are completed in one process, the work process is reduced as compared with the conventional technique, and the width of the road R can be widened because the side groove is not constructed.

  The technique of the present invention is used to construct a retaining wall.

DESCRIPTION OF SYMBOLS 10 Excavator 11 Outer shell 12 Bulkhead 12a Earth discharge port 13 Motor 13a Output shaft 14 Rotating cutter 14a Bevel gear 14b Transmission shaft 14c Protective cover 15 Spoke cutter 16 Earth removal device 17 Mud conveyor 20 Retaining wall block 21 Water channel 22 Insertion tube 23 Drainage pipe 24 Drainage pipe 25 Box extraction part 26 Filling 30 Starting shaft 31 Main pusher 32 Starting stand 40 PC bar 41 Tightening nut 50 Reinforcement 51 Concrete C Cast-in-place pile G Ground mountain R Road

Claims (5)

By digging a part of the ground of slopes along slopes and road trying to build a retaining wall to construct a starting pit, the portrait having a water channel inside the rear end of the shield tunneling machine capable of excavating the substantially trapezoidal cross section A trapezoidal retaining wall block with a sloping road side is connected at the start shaft, and the retaining wall block is pushed with a main pusher installed on the start shaft, and excavated soil is excavated in the excavator while excavating the natural ground with the excavator. Intake and discharge to the rear through the channel of the retaining wall block, connect the next retaining wall block to the rear of the retaining wall block, repeat the excavation of the excavator and the addition of the retaining wall block until reaching the predetermined reaching position, Precast retaining wall propulsion, characterized by water retaining connections between retaining wall blocks with a stainless steel or steel collar to form retaining walls and water channels, and then removing roadside topsoil on retaining wall blocks Construction method.   The precast according to claim 1, wherein during the excavation, the solidified lubricant is simultaneously filled in the gap between the retaining wall block and the natural ground from the excavator, and backfilling is performed in the gap after the completion of propulsion. Retaining wall propulsion method.   After embedding the retaining wall block in the ground, the ground is drilled from the bottom of the water channel inside the retaining wall block, a reinforcing bar is inserted into the drilled hole, and concrete is filled to form a cast-in-place foundation pile. The precast retaining wall propulsion method according to 1 or 2.   2. A retaining wall block in which a hole into which a steel bar can be inserted is formed along a water channel is used, and a long steel bar is connected to the retaining wall block from the start to the end after propulsion and tightened for integration. The precast retaining wall propulsion method according to any one of? 3. It claims 1-4 excavator to be used for precast retaining wall jacking method according any one, fitted with a septum front to dumping opening trapezoidal shell is opened to the side of the road in the longitudinal length is inclined, the partition wall A plurality of motors with speed reducers are mounted in a row on the inner surface of the motor, and the output shaft protrudes in front of the bulkhead, and a rotary cutter that rotates like a wheel via a bevel gear is attached to the output shafts of the upper motors. A precast retaining wall propulsion method that has a structure in which a cross-shaped spoke cutter is attached to the lower motor, and a soil removal device is connected to the soil discharge port and attached to the outer shell.

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