JP2007191972A - Underpass construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for completing a slope in a short period of time in constructing an underpass. <P>SOLUTION: A shaft 20a is excavated in the lowermost part of an underpass slope from the ground, and a bore hole reaching the starting point of the slope is provided from the inside of the shaft 20a along the road surface of the slope. A traction rope 40 is inserted through the bore hole, and a traction jack 41 is mounted to the vertical shaft internal end of the traction rope 40. On the ground behind the starting point of the slope, concrete case blocks 50a, 50b, 50c, etc. of U-shaped cross section forming the bottom plate and sidewalls of the slope are manufactured, and the traction rope 40 is locked in a replaceable manner to each divided block. The respective blocks are advanced by turns while excavating sediment of the slope by the leading end of the concrete case block 50a to install the concrete case blocks 50a, 50b, 50c, etc. as the bottom plate and sidewalls of the slope. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an underpass construction method, and more particularly, to a technique for quickly constructing an underpass ramp.

  In order to change a plane intersection road to a three-dimensional intersection, there is an underpass method in which one road is dug to form an underpass. Previously, it was a process in which earth retaining was performed using sheet piles, the side walls and bottom plate of the ramp were formed with cast-in-place concrete inside, and the upper road was created by enforcing the floor slab on the side walls. In order to improve this, there is a technique in which square piles are arranged side by side and driven into the ground to form an underground wall, and this underground wall is used as a side wall of an oblique road. This technique still has a problem in water-stopping of the side wall.

  To construct the underpass quickly, two consecutive prestressed prestressed concrete piles with an H-shaped cross-section are placed in the ground in order to be continuous to the side wall of the underpass. There is a technique of forming underground walls and excavating between the underground walls to form an underpass (for example, see Patent Document 1).

  With this technology, two continuous underground walls that are easy to set up, have high strength, have good water-stopping properties, and are suitable for rapid construction are formed. The underpass is constructed by excavating between the underground walls and constructing an underpass bottom plate to form a ramp with the underground wall as a side wall. In addition, a road floor slab is installed on the underground wall to form the upper road.

  Compared with the conventional underpass method, this technology has a feature that it is rich in water-stopping, and can be constructed quickly and at low cost.

  However, even with this technology, there are further points to be improved, such as the need to block traffic on the upper road during the underpass creation process, and the formation of the underpass side wall and bottom plate at a different time from the pile driving process. .

  As a technique for further improving such a technique, it is conceivable that the upper road is constructed by tunnel formation by a propulsion method without blocking traffic, and the ramp is constructed by an open shield method.

  There is a so-called fronte jacking method as a road tunnel enforcement technique by the propulsion method.

  The open shield method is a technique that combines an open cut method (open cut method), which is a method for constructing underground structures such as water and sewage systems, and common grooves, and a shield method (see, for example, Patent Document 2).

In the open shield method, the left and right side walls and bottom plate are used, and the front, rear and top surfaces of the shield machine are used, and the propulsion jack provided in the shield machine is used to move forward while excavating the front of the Schild machine. To do. Then, an underground structure is constructed by installing a U-shaped grooved concrete box in the back space formed by excavation.
Japanese Patent Laying-Open No. 2005-23576 (page 3-6, FIG. 1) JP-A-7-269289 (page 2-4, FIG. 3)

  The present invention aims to develop and provide an underpass construction method that solves the above problems.

  That is, in the present invention, in constructing the underpass, the ramp produces a concrete box that forms the side wall and the bottom plate of the ramp, and the concrete box is pulled and excavated at the ramp position while excavating the ramp. The purpose is to provide a technique for forming a ramp at once without providing a retaining wall and completing the ramp in a short construction period.

  Further, according to the present invention, the underpass portion under the cross road is constructed by a tunnel forming technique using a propulsion method, separately from the construction of the above-described ramp, so that the construction can be quickly performed without blocking the traffic on the upper road.

  This makes it unnecessary to block traffic and shortens the overall construction process.

  The present invention has been made to solve the above problems, and is an underpass construction method characterized by taking the following technical means.

  In constructing the underpass, the present invention excavates a shaft from the ground on the lowest side wall portion of the underpass ramp, and from the inside of the shaft along the road surface of the underpass to the ramp side wall portion of the underpass A drilling hole is inserted into the borehole, and a tow jack is attached to the end of the shaft of the towline. On the other hand, on the ground behind the starting point of the ramp, the bottom plate and side wall of the ramp A concrete box having a U-shaped cross section is manufactured, and the tow rope is locked to the concrete box, and the concrete box is formed while excavating the earth and sand of the ramp at the leading end of the concrete box. The underpass construction method is characterized in that the concrete box itself is used as a bottom plate and a side wall of a ramp.

  In the above construction method, the concrete box is divided into a plurality of blocks in the longitudinal direction of the oblique road, the pulling rope is slidably locked to each divided block, and each divided block is advanced and advanced alternately. The traction resistance is reduced, and the operation is facilitated.

  Excavating the block foundation at the tip of the divided block below the planned ground height, and creating the normal ground with the next block, the ground height (concrete box installation accuracy) can be accurately determined. It can be constructed, the excavation accuracy of the tip block tip may be set appropriately, and the technical difficulty of securing the ground height system at the same time by rough excavation can be easily overcome.

  Further, the vertical pile is formed by sinking a concrete frame, a vertical ground anchor is preliminarily constructed around the vertical pile, and the ground anchor is used as a reaction force support device for setting up a concrete frame of a vertical shaft. Can be easily excavated, and can be effectively used as a reaction force support device for the traction force of the tow rope by using the reaction force as a reaction force support device for the upward component force of the tow rope when towing the tow rope. .

  Furthermore, the concrete frame is formed as an open surface in which the inner surface of the underpass is covered with a temporary plate, so that the underpass tunnel under the cross road can be easily formed by excavating the sand between the vertical shafts on both side walls. The propulsion base and the arrival base can be formed.

  It should be noted that if the concrete box of the ramp is pulled with a jack that pulls the ramps at the same time on both ramps, the reaction force is borne by each other, and a special reaction force support device is not required. It is.

  Furthermore, in the present invention, a propulsion base and a reaching base are formed by excavating the earth and sand between the vertical shafts formed on the both side walls, a pipe roof is formed below the upper road between the propulsion base and the reaching base, If a method of constructing a tunnel under the pipe roof and using it as an underpass is used in combination, high-efficiency construction of the entire process can be performed, which contributes to shortening the construction period.

  Since the underpass construction method of the present invention is configured as described above, there is no need to provide a retaining wall or the like, and there is an excellent effect that an excellent ramp can be constructed in a short construction period.

  Further, according to the present invention, the underpass portion under the cross road is constructed by a tunnel forming technique using a propulsion method, separately from the construction of the above-described ramp, so that the construction can be quickly performed without blocking the traffic on the upper road. As a result, it is not necessary to cut off traffic on the crossing road, and the entire construction process can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 21 is a side view of an example of the underpass 100, and FIG. 22 is a plan view thereof. In the intersection road 120, an underpass 100 is formed under one upper road 130, which is composed of ramps 110 a and 110 b and a lower road (a tunnel in this figure) 140. 21 and 22, the first pit 150 a and the arrival mine 150 b for forming the tunnel 140 are shown.

  Conventionally, when the underpass 100 is constructed, retaining walls are provided on both sides of the underpass, the slopes 110a and 110b and the lower road 140 are constructed by excavating between the retaining walls, and the upper road 130 is floored on the retaining wall. A plate was installed and constructed. As a retaining wall, a technique is also known in which prestressed concrete piles having an H-shaped cross section are connected side by side and driven into the ground, and the connecting pit wall itself is used as an underpass side wall.

  The present invention is a technique for efficiently constructing the underpass 100 in a short construction period by eliminating the step of forming the retaining wall in advance. That is, in constructing the underpass, the present invention forms a ramp by the following steps (1) to (4).

  (1) A shaft is excavated from the ground on the lowest side wall of the underpass ramp.

  (2) A boring hole extending from the shaft to the starting point of the ramp along the road surface of the ramp is provided, the towing line is inserted into the bore hole, and a tow jack is attached to the end of the towing line in the shaft.

  (3) On the other hand, on the ground behind the starting point of the ramp, a U-shaped concrete box that forms the bottom plate and side walls of the ramp is manufactured.

  (4) Excavate the soil of the ramp at the leading end of the concrete box, pull the concrete box with a tow rope while forming the ramp, and use the concrete box itself as the bottom plate and side wall of the ramp.

  The concrete box should be divided into a plurality of concrete blocks and advanced forward.

  1 to 3 are views showing a shaft of the present invention for constructing a ramp, FIG. 1 is a plan view, FIG. 2 is a sectional view taken along the line AA, and FIG. is there.

  In the road that becomes an underpass, the shafts 20a, 20b, 20c, and 20d are press-fitted and installed on both side walls adjacent to the road intersection by using an open caisson method. The vertical piles 20a, 20b, 20c, and 20d serve as bases and reaction force supports for pulling the concrete box of the later-described ramp, serve as earth retaining for excavation, and reach the first mine for tunnel construction under the upper road described later. Become part of the mine.

  As shown in FIG. 1, shafts 20 a, 20 b, 20 c, and 20 d are provided in portions adjacent to the upper road 130 on the side walls of the ramps 110 a and 110 b of the underpass 100. The shafts 20a, 20b, 20c, and 20d are provided on the underpass side wall at the lowest position of the underpass ramps 110a and 110b. As an example, the dimensions of the shaft are horizontal (3-5 m) × vertical (15-25 m) × depth (10-15 m).

  As shown in FIGS. 1 and 2, a ground anchor 30 is preliminarily constructed from the ground surface around the shaft, and the reaction force of the press-fitting of the concrete frame 21 of the shaft is supported by the ground anchor 30 to press the concrete frame 21 into the ground. Let it sink.

  This concrete pile 21 is provided with a blade 22 at the lower end. The concrete frame 21 may be a vertical shaft with a rectangular cross section in which the inner surface of the underpass is opened and the open surface is closed with a temporary wall 23. If it carries out like this, the earth and sand between opposing shafts 20a and 20b can be excavated, and the below-mentioned initial pile and reach | attainment pile can be provided easily, and the tunnel under the upper road 130 is formed using this start pile and reach | attainment pile. Convenient for.

    4 to 8 are side sectional views showing the steps of the present invention. First, a boring hole obliquely upward along the inclined road is drilled from the shaft 20a, and the tow rope 40 is inserted into the hole. A towing jack 41 is attached to the end of the towing line 40 in the shaft. The towing jack 41 supports the weight of the shaft 20a and the like, and the ground anchor 30 for the reaction force.

  On the other hand, a concrete box 50 having a U-shaped cross section on the ramp is manufactured behind the starting point of the ramp. With the jack 41, the concrete box 50 is pulled diagonally in a direction along the ramp. 4 to 8 show only the shaft 20a, the shafts 20a and 20b cooperate to pull the concrete box on the ramp. The other shafts 20c and 20d also pull the concrete box on the other ramp. Both ramps can be constructed simultaneously, and the traction reaction forces of the towing lines can be balanced with each other by connecting the tail ends of the towing lines of both ramps.

  As shown in FIG. 11, the concrete box 50 has a U-shaped cross section including a bottom plate 51 serving as a road surface of a ramp and standing walls 52 serving as both side walls. The bottom plate 51 is equal to the width of the underpass road, and the standing wall 52 forms earth retaining walls (side walls) on both sides of the ramp. The concrete box 50 is manufactured by dividing the longitudinal direction into a plurality of blocks 50a, 50b, 50c,... To reduce the traction force.

  FIG. 4 shows a pulling process of the leading block 50a of the concrete box 50 forming the ramp. The tow rope 40 is attached to the bracket 55 of the leading block 50a.

  FIG. 5 shows a process of pulling the second block 50b following the tail end of the leading block 50a. When the head block 50a is pulled and moved forward until a space is obtained in which the second block 50b can be manufactured, the second block 50b is manufactured.

  When the towing line 40 pulls the leading block 50a by one step, the locking of the towing line 40 of the leading block 50a is released to make the leading block 50a free. Then, the tow rope 40 is replaced with the second block 50b, the tow rope 40 is fixed to the second block 50b, and the second block 50b is followed by one step until it touches the head block 50a. Tow. Next, the locking of the tow rope 40 of the second block 50b is released to make the second block 50b free, the tow rope is fixed to the head block 50a, and the head block 50a is moved by the length of the retaining plate 56. Move forward.

  In this way, the block is sequentially pulled by the scale insect method. A retaining plate 56 is provided between the first block 50a and the second block 50b. The dimension in the forward direction of the retaining wall 56 is longer than the step distance of one surface of the block. For example, the step distance of one surface is set to 2 to 3 m, and the step size of the earth retaining plate is set to 4 to 5 m.

  Next, the third block 50c and then the fourth block 50d are sequentially manufactured behind the second block 50b, and these are followed by the second block 50b. The excavation of the front surface of the top block 50a and the advance of the top block are performed again, and the following step operation of each block is repeated.

  6 and 7 show a state where the succeeding blocks 50c and 50d are sequentially followed and pulled. Since the blocks 50a, 50b, 50c, and 50d are sequentially advanced, a retaining plate 56 that closes a gap on a side portion that occurs during the step is attached between the blocks. Moreover, the bracket 55 which fixes the tow rope 40 is attached inside each block.

  FIG. 8 shows a state where traction is completed. As shown in FIG. 8, when all the blocks 50a, 50b, 50c, and 50d are pulled to a predetermined position, the joints of the connecting portions of the respective blocks are constructed to complete the formation of the ramps.

  The traction process will be described in more detail with reference to FIGS.

  9 is a plan view of the pulling process, FIG. 10 is a side view thereof, and FIG. 11 is a cross-sectional view taken along the line CC in FIG. As shown in FIG. 11, the concrete box 50 (concrete blocks 50a, 50b, 50c, 50d) has a U-shaped cross section composed of a bottom plate 51 and both side walls 52. The bottom plate 51 and the standing wall (side wall) 52 form the bottom plate and the side wall of the underpass ramp as it is.

  For example, the inner diameter is 18 to 20 m, the side wall has a maximum height of 8 to 10 m, and the block length is 15 to 25 m.

  9 and 10, the front block 50a is excavated by the excavator 60, and the excavated soil is transported and discharged by the dump truck 61 or the like. While excavating and excavating with the excavator 60, the leading block 50 a is advanced by towing the tow rope 40 while cutting the ground with the blade 54.

  It is not always easy to excavate the ground by the excavator 60 so that the ground matches the concrete box ground. Therefore, the excavator 60 excavates the ground height a little, adjusts the ground height in the gap between the leading block 50a and the second block 50b, and forms the reference ground. It is preferable to slide the block on the reference ground and pull it. In this case, since the lower surface of the leading block 50a is excavated a little, finally, concrete or the like is placed in the leading block 50a to adjust the road surface height of the ramp.

  12 is a plan view for explaining the state of excavation of the earth and sand in front of the leading block 50a, FIG. 13 is a side view thereof, and FIG. 14 is a front view thereof.

  As shown in FIG. 12, when the earth and sand in front of the leading block 50a are excavated by the excavator 60, the excavation slopes 62 and 63 have a semi-conical shape, and the leading block 50a moves deeper into the basement. Only the excavator 60 operating on the bottom surface 50a cannot excavate near the top of the slope near the side walls.

  In such a case, the gantry 64 is assembled at the tip of the leading block 50a, the work table 65 is formed on the upper surface, and the excavator 60a is placed on the work table 65, as shown in FIGS. Sediment around the top of slopes 62, 63 is excavated.

  FIG. 15 is a side view showing a tow bracket 55 provided on each concrete block, FIG. 16 is a front view thereof, and FIG. 17 is a perspective view showing an example of the bracket 55. The bracket 55 is coupled to the reinforcing bar 57 in the concrete block 50a and is firmly attached integrally. For example, as shown in FIG. 17, the anchor coupler 43 is fixed to the tow rope 40 and the anchor coupler 43 is supported by the slit plate 42, and the slit plate 42 is a face plate 58 of the bracket 55. Lock to support.

  The bracket 55 shown as an example is provided with a slit or hole 59 having a size capable of allowing the anchor coupler 43 attached for fixing the tow rope 40 to pass therethrough. Further, by inserting the slit plate 42 between the anchor coupler 43 of the tow rope 40 passing through the slit or hole 59 of the placket 55 and the face plate 58 of the bracket 55, the tow rope 40 is locked and supported by the bracket 55. It has a structure.

  The slit plate 42 includes a slit 45 through which the tow rope 40 passes. By pulling the slit plate 42 upward as shown in FIG. 15, the anchor coupler 43 and the slit plate 42 are disengaged. The anchor coupler 43 can pass through a slit or hole 59 provided in the face plate 58 of the bracket 55. Accordingly, it is possible to easily step the concrete block 50a intermittently by changing the tow rope 40.

  Next, with reference to FIGS. 18 to 20, the construction of the underpass in the portion under the upper road 130 used in the present invention will be described. This technique itself is a known technique. A technology that uses a pipe roof to construct a tunnel by the propulsion method, and uses this together.

  As shown in FIG. 18, the earth and sand between the opposing vertical shafts 20a and 20b and between the adjacent vertical piles 20c and 20d are respectively excavated to form the propulsion shaft 150a and the reaching shaft 150b. At this time, if the inner side surfaces of the shafts 20a, 20b, 20c, and 20d are set as open surfaces, the operation is easy.

  As shown in FIG. 20, a pipe is inserted between the start pit 150a and the arrival pit 150b to form a pipe roof 70 as shown in FIG. The pipe roof 70 supports the upper road 130. Therefore, the traffic blocking of the upper road 130 can be omitted or limited to only a short time.

  Under the pipe roof 70, a tunnel member 80a such as a box culvert is propelled and pressed by a propulsion method to form a tunnel. FIG. 19 shows a system in which a tunnel member 80a (propulsion pipe) is propelled from the propulsion pit 150a, and another tunnel member 80b (propulsion pipe) is propelled from the reaching pit 150b and coupled in the middle.

  The propulsion means is not limited to this, and the tunnel member 80a may be propelled only from one side by taking a reaction force on the propulsion pit 150a, or the propulsion rod or the like is penetrated to the other pile, and the tip side is made to the other side. The tunnel member may be propelled from one direction by this propulsion rod supported by a reaction force device provided in the pit.

It is a top view which shows the standing pile of an Example. It is AA arrow sectional drawing of FIG. It is BB arrow sectional drawing of FIG. It is a sectional side view which shows the construction method of this invention. It is a sectional side view which shows the construction method of this invention. It is a sectional side view which shows the construction method of this invention. It is a sectional side view which shows the construction method of this invention. It is a sectional side view which shows the construction method of this invention. It is a top view of a traction process. It is a side view of a traction process. It is CC sectional view taken on the line of FIG. It is a top view explaining front surface excavation. It is a side view explaining front surface excavation. It is a front view explaining front surface excavation. It is a side view of the bracket for traction. It is a front view of the bracket for traction. It is a perspective view of the bracket for towing. It is explanatory drawing of the underpass construction under the upper road. It is explanatory drawing of the underpass construction under the upper road. It is explanatory drawing of the underpass construction under the upper road. It is a whole side view of an example of an underpass. It is a whole top view of an example of an underpass.

Explanation of symbols

20a, 20b, 20c, 20d Standing pile 21 Concrete frame 22 Cutting edge 23 Temporary wall 30 Ground anchor 40 Towing rope 41 Towing jack 42 Slit plate 43 Anchor coupler 45 Slit 50 Concrete box 50a, 50b, 50c, 50d, Concrete block 51 Bottom plate 52 Standing wall (side wall)
54 Cutting edge 55 Bracket 56 Dust plate 57 Reinforcing bar 58 Face plate 59 Slit or hole 60, 60a Excavator 61 Dump truck 62, 63 Excavation slope 64 Mounting base 65 Work table 70 Pipe roof 80a, 80b Tunnel member 100 Underpass 110a, 110b Ramp 120 Intersection 130 Upper road 140 Road under road 150a Propulsion mine 150b Arrival mine

Claims (6)

  In constructing the underpass, a shaft is excavated from the ground on the lowest side wall of the underpass ramp, and a borehole is formed from the shaft along the road surface of the ramp to the starting point of the ramp. A concrete box with a U-shaped cross-section that inserts a tow rope into the shaft and attaches a tow jack to the end of the shaft of the tow line, and forms a bottom plate and a side wall of the ramp on the ground behind the starting point of the ramp The towline is locked to the concrete box, and the concrete box is towed by the towline while excavating the sludge of the ramp at the leading end of the concrete box to form the ramp. An underpass method characterized in that the box itself is the bottom plate and side walls of the ramp.   2. The concrete box is divided into a plurality of blocks in the longitudinal direction of the ramp, the tow rope is slidably locked to each divided block, and each divided block is advanced and advanced alternately. The underpass construction method described.   The ground below the block at the tip of the divided block is excavated below a planned ground height, and the next block is pulled at the tail end of the block at the tip, after the regular ground is created. 2. Underpass construction method described in 2.   The shaft will be formed by sinking a concrete frame, a vertical ground anchor will be pre-constructed around the shaft, the ground anchor will be used as a reaction force support device under the concrete frame pressure of the shaft, and The underpass construction method according to any one of claims 1 to 3, wherein the underpass construction method is used as a reaction force support device for upward component force of tractive force.   The underpass construction method according to any one of claims 1 to 4, wherein the concrete frame is an open surface in which an inner surface of the underpass is covered with a temporary plate.   Excavation soil between the shafts formed on the both side walls is formed to form a propulsion base and a reaching base, a pipe roof is formed below the upper road between the propulsion base and the reaching base, and below the pipe roof The underpass construction method according to any one of claims 1 to 5, wherein a tunnel is constructed by a propulsion construction method to form an underpass.

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