JPH041122B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for adjusting and fixing the position of a half-arch for forming an arch ring of an arch bridge constructed by a lowering (lowering rotation) method. .

[Prior art]

Conventionally, when constructing an arch ring of an arch bridge using the lower ring method, first, as shown in FIG. , a bridge abutment 10 and an anchor block 11 are built, a stiffening girder 12 is erected and fixed across the abutment 9 and abutment 10, and a push-pull hydraulic pressure is installed in a guide rail 13 with a groove-shaped cross section extending in the front and back direction. A half-arch push-pull device 15 is constructed by arranging the rear part of the horizontal arm 14 that is moved in the front-rear direction by a jack, and the guide rail 13 of the half-arch push-pull device 15 is fixed to the stiffening girder 12. The lower shoe of the rotary support 16 is fixed to the arch abutment 5.

Next, using the climbing formwork 17, construct a concrete half-arch 6 on top of the upper shoe of the rotary support 16 in an almost vertical state from below to above until it reaches a position slightly higher than the bridge surface. After constructing the half arch 6, the front end of the horizontal arm 14 of the half arch push/pull device 15 is connected to the half arch 6 with a pin, and then the half arch is connected via the horizontal arm 14 by the push/pull hydraulic jack. The arch 6 is pulled backwards, its half-arch 6 is tilted backwards, and then the climbing form 17 is again
The half-arch 6 is completed by sequentially moving the half-arch upward and adding the half-arch constituent parts.

Next, the half-arch 6 is pressed and rotated forward via the horizontal arm 14 by the push-pull hydraulic jack, thereby tilting the half-arch 6 forward.

Next, a lowering cable 19 is stretched between the distal end portion of the half arch 6 and the feeding hydraulic jack 18 connected to the anchor block 11, and then,
The horizontal arm 14 is removed from the half-arch 6, and the lower ring cable 19 is gradually let out from the pay-out hydraulic jack 18, while the half-arch 6 is rotated downward to a predetermined arch ring installation position. An arch ring construction method is known in which an arch crown part is constructed between the tips of arches 6 (for example, "Bridges and Foundations", Vol. 20, No. 12, published by Kensetsu Tosho Co., Ltd., December 1, 1985). (See pages 17-20).

[Problem that the invention seeks to solve]

When an arch ring is erected using the conventional construction method described above, half arches are constructed on arch abutments on both banks, so in reality, discrepancies occur at the tips of the half arches on both sides due to the following reasons. do.

(1) The half-archs on both banks are supported by independent rotary bearings, but it is difficult to install each rotary bearing in the predetermined position of the arch abutment with high precision, and during the construction and lowering of the half-arch Torsion may occur in the rotary bearing, which causes a misalignment of the tips of the two half-arches after lowering.

(2) If the half-arches are not constructed to the specified size and shape, there will be discrepancies between the ends of the half-arches on both sides after lowering.

(3) If the arch abutments on both banks settle unevenly,
After lowering, there is a discrepancy between the tips of the half arches on both sides.

As mentioned above, if the tips of the half arches on both sides are misaligned after lowering, it is impossible to form an arch ring with a predetermined shape.

[Purpose and structure of the invention]

The object of the present invention is to provide a method for correcting and fixing the position of a half arch for forming an arch ring in an arch bridge, which can advantageously solve the above-mentioned problems. are connected to the lower shoe 2 by a horizontal shaft 3 so as to be freely rotatable and movable upward relative to the lower shoe 2 to form a rotary support 4, and the lower shoe 2 of the rotary support 4 is fixed to arch abutments 5 on both banks. Then, after constructing a half arch 6 from below to above on the upper part of the upper shoe 1 in the rotary support 4, the half arch 6 is rotated downward about the horizontal axis 3 to the arch ring installation position, Next, after correcting the discrepancy in the tip of each half-arch 6 with the jacks 7 interposed between the left and right sides of the base end of the half-arch 6 and the arch abutment 5, the difference between the base end of the half-arch 6 and the arch abutment 5 is corrected. This method of correcting and fixing the position of a half-arch for forming an arch ring in an arch bridge is characterized in that fixing concrete 8 is poured between them to fix the base end of the half-arch 6 to an arch abutment 5.

〔Example〕

Next, the present invention will be explained in detail using illustrated examples.

13 to 15 show a rotary support 4 used in an embodiment of the present invention, in which a horizontal shaft insertion hole 22 is provided in the upper part of a base plate 21 having a plurality of anchor bolt insertion holes 20. A support plate is provided with a plurality of vertical lower brackets 23 integrally arranged in parallel to constitute a steel lower shoe 2, and is provided with a plurality of anchor rod insertion holes 24 and positioning recesses 25. At the bottom of 26, there is a long hole 27 for horizontal shaft insertion that extends vertically.
A plurality of vertical upper brackets 28 with
8 is inserted between the lower brackets 23 of the lower shoe 2, and the steel horizontal shaft 3 is inserted between the horizontal shaft insertion through hole 22 of each lower bracket 23 and each upper bracket 2.
8 through the horizontal shaft insertion hole 27,
A washer 30 for preventing the horizontal shaft from coming off is fitted into a small-diameter screw rod 29 that is integrally connected to both ends of the horizontal shaft 3, and a fixing nut 31 is screwed into the screw rod 29, which has a small diameter. A gap G is provided between the lower part and the lower part of the horizontal shaft insertion through hole 27 to allow upward movement of the upper shoe 1 with respect to the lower shoe 2.

Next, a method for correcting and fixing the position of a half-arch for forming an arch ring according to an embodiment of the present invention using the above-mentioned rotary support 4 will be described.

First, as shown in Figures 1 to 3, the arch abutment 5 and the abutment 32 are constructed at both ends of the planned arch ring installation position, and the anchor block 33 located behind the abutment 32 is constructed, and the anchor block 33 is constructed at the rear of the abutment 32. 33 is firmly fixed to the ground by a large number of lock anchors 34, and furthermore, the lower part of an anchor bolt 35 for fixing the lower foot of the rotation support is embedded in a predetermined position of the arch abutment 5.

Next, the lower shoes 2 of the rotary supports 4 arranged at intervals in the left-right direction on the arch abutment 5 are fixed to the arch abutment 5 using the anchor bolts 35 and the nuts 36 screwed thereto, and the upper shoes of the rotary supports 4 are A fixing pin 37 is inserted between the upper shoe 1 and the lower shoe 2 to prevent rotation of the upper shoe 1, and a positioning protrusion 39 provided at the center of the steel adjustment plate 38 is inserted into the support plate of the upper shoe 1. 26
While fitting into the positioning recess 25 in
The adjustment plate 38 is placed on the support plate 26, the lower portions of the plurality of anchor rods 40 are inserted through the support plate 26 and the steel adjustment plate 38, and a pair of nuts 41 are screwed into the lower portions of the anchor rods 40. 42 fixes the support plate 26 and the steel adjustment plate 38 to the lower part of the anchor rod 40.

Next, using a known climbing formwork 43,
Concrete half-arches 6 are sequentially constructed from the bottom to the top on top of the upper shoe 1.

With the half arch 6 of a predetermined length constructed, the fourth
As shown in FIG. 6, one end of a pulling cable 44 made of wire rope is inserted into the middle part of the half arch 6 and fixed by a fixing device 45, and the other end of the pulling cable 44 is is inserted into the middle part of the half-arch 6 on the opposite bank, and a pulling hydraulic jack 46 consisting of a cylinder with a cable clamp and a piston rod with a cable clamp is installed on the anchor block 33 on the opposite bank, and the pulling cable 44 The other end portion is held by the cable clamp, and the pulling cable 44 is tensioned by the pulling hydraulic jack 46.

In addition, one end of two lower ring cables 19 made of wire ropes are inserted into the tip of the half arch 6 and fixed by a fixing device 47, and a lower ring made of a cylinder having a cable clamp and a piston rod having a cable clamp. A ring hydraulic jack 48 is installed on the anchor block 33 at the rear of the half arch 6, and the lower ring cable 19
The other end is held by the cable clamp, the lowering cable 19 is tensioned by the lowering hydraulic jack 48, and the fixing pin 37 is removed to complete the preparation for lowering work.

When performing lowering work, first tension the pulling cable 44, and
4, the two lower ring cables 19 are gradually let out from the lower ring hydraulic jack 48, as shown in FIG.
Lower the half arch 6.

The half-arch 6 is lowered by repeatedly tensioning the pulling cable 44 and letting out the lowering cable 19 in small steps many times as described above, and then the half-arch 6 is lowered from the valley side. When the half arch 6 does not turn over to the lowering cable side due to the action of wind or seismic force, and is in a state where it naturally rotates downward due to the weight of the half arch 6,
The pull cable 44 is relaxed and removed, and the lower ring cable 19 is gradually let out from the lower ring hydraulic jack 48 again, and the half arch 6 is lowered by its own weight to the predetermined arch ring installation position shown in FIG. 7. Then, the other half arch 6 is also rotated downward to a predetermined arch ring installation position by the above-described means.

When the lowering of the half arches 6 on both sides has been completed, if there is a discrepancy in the tip of each half arch 6, for example, the tip of one half arch 6 may be different from the tip of the other half arch 6. If it is deviated in the left-right direction or twisted, as shown in FIG. Alternatively, by extending both jacks 7 by an appropriate amount, the half arches 6 are moved to correct the discrepancy between the tips of the half arches 6 on both sides.

Next, as shown in FIG. 7, a groove-shaped formwork 49 supported by suspension supports is placed across the tips of the half-arches 6 on both sides, and concrete is poured into the formwork 49. After constructing the arch crown portion 50 and hardening the concrete of the arch crown portion 50, the lowering cable 19 is
was loosened and removed, and as shown in FIGS. 9 and 10, reinforcement was placed between the base end of the half arch 6 and the arch abutment 5 between the left and right rotation bearings 4. Intermediate fixing concrete 51
After the intermediate fixing concrete 51 has hardened, each jack 7 is shortened and removed, and then, as shown in FIG. In between, reinforcing is arranged and side fixing concrete 52 is cast, and the rotation bearing 4 is embedded in the side fixing concrete 52, and the intermediate fixing concrete 51 and side fixing concrete 52 are placed. The base end of the half-arch 6 is fixed to the arch abutment 5 with a fixing concrete 8 consisting of.

After erecting the arch ring 53 consisting of the pair of half arches 6 and the arch crown portion 50 as described above, a support is assembled on top of the arch ring 53, and as shown in FIG.
Then, the upper deck slab 55 is constructed to complete the arch bridge.

When carrying out this invention, only the half-arch 6 on one side may be moved by the jack 7 to correct the discrepancy in the tips of each half-arch 6, or the half-arch 6 on both sides may be moved by the jack 7. , the discrepancy between the tips of each half-arch 6 may be corrected.

Upper shoe 1 without using the steel adjusting plate 38
Alternatively, the jacks 7 may be directly connected to the support plate 26 on the support plate 26, or the jacks 7 may be attached to the concrete 8 poured between the base end of the half arch 6 and the arch abutment 5 without removing the jacks 7. May be embedded.

〔Effect of the invention〕

According to this invention, the rotation support 4 is constructed by connecting the upper shoe 1 to the lower shoe 2 so as to be rotatable about the horizontal shaft 3 and to be able to move upwardly relative to the upper shoe 2.
The lower shoe 2 of the rotary support 4 is fixed to the arch abutments 5 on both banks, and a half arch 6 is constructed from below upwards on the upper part of the upper shoe 1 of the rotary support 4, and then the half arch 6 is The simple operation is to rotate the arch ring downward about the shaft 3 to the installation position, and then extend the jacks 7 interposed between the arch abutment 5 and the right and left sides of the base end of the half arch 6 by an appropriate amount. By doing so, it is possible to easily and quickly correct the discrepancy between the tips of the half-arches 6 on both sides, and the effect that the arch ring 53 of a predetermined shape can be formed can be obtained.

[Brief explanation of drawings]

Figures 1 to 15 show an embodiment of the present invention, in which Figure 1 is a partially longitudinal side view showing a half-arch being constructed using a climbing form; Figure 2 is an enlarged partial vertical sectional side view showing the vicinity of the rotation bearing in Figure 1, Figure 3 is a partial vertical front view enlarged and showing the vicinity of the rotation bearing in Figure 1, and Figure 4 is a half arch. Fig. 5 is a side view showing a part of Fig. 4 enlarged, and Fig. 6 is a side view showing the state when lowering is started.
FIG. 7 is a plan view showing an enlarged view of the vicinity of the anchor block in the figure, and FIG. 7 is a side view showing a state in which the half arches on both sides have been lowered to a predetermined position and the arch crown portion has been constructed. Figure 8 is a front view showing the state in which the jacks have been installed between the base end of the half-arch and the arch abutment, and Figure 9 is a front view showing the state in which the jacks have been placed between the base end of the half-arch and the arch abutment. Front view showing the condition, Figure 10 is the 9th
11 is a front view showing intermediate fixing concrete and side fixing concrete placed between the base end of the half arch and the arch abutment, and FIG. 12 is a sectional view taken along the line A-A in the figure. FIG. 3 is a partially longitudinal side view showing a state in which the ring has been installed. FIG. 13 is a vertical sectional front view of the rotary support, FIG. 14 is a vertical sectional side view thereof, and FIG. 15 is a front view of the rotary support. FIG. 16 is a side view for explaining a conventional arch ring erection method using a half-arch rotation device. In the figure, 1 is the upper shoe, 2 is the lower shoe, 3 is the horizontal axis, 4 is the rotation support, 5 is the arch abutment, 6 is the half arch, 7 is the jack, 8 is the fixing concrete, 19 is the lowering cable, and 23 is the Lower bracket, 27 is a long hole for horizontal shaft insertion, 28 is an upper bracket, 33 is an anchor block, 35 is an anchor bolt, 36 is a nut, 37 is a fixing pin,
40 is an anchor rod, 41 and 42 are nuts, 4
3 is the climbing formwork, 44 is the pulling cable,
45 is a fixing device, 46 is a hydraulic jack for pulling, 4
7 is a fixing device, 48 is a hydraulic jack for lowering, 49 is a formwork, 50 is an arch crown portion, 5
1 is intermediate fixing concrete, 52 is side fixing concrete, and 53 is an arch ring.

Claims (1)

[Claims] 1 The upper shoe 1 is connected to the lower shoe 2 by a horizontal shaft 3 so as to be freely rotatable and movable upward relative to the lower shoe 2 to form a rotary support 4, and the lower part of the rotary support 4 is connected to the arch abutments 5 on both banks. Fix shoe 2,
After constructing a half-arch 6 from below to above on the upper part of the upper shoe 1 in the rotation bearing 4, the half-arch 6 is rotated downward about the horizontal axis 3 to the arch ring installation position, and then half arch 6
After correcting the discrepancy in the tip of each half-arch 6 with the jacks 7 interposed between the left and right sides of the base end of the arch abutment 5 and the arch abutment 5, fixing concrete is installed between the base end of the half-arch 6 and the arch abutment 5. 8. A method for correcting and fixing the position of a half-arch for forming an arch ring in an arch bridge, characterized by fixing the proximal end of the half-arch 6 to an arch abutment 5 by pouring a half-arch.