CN115058989A - Construction method for rapidly dismounting single-column-pier single-box-chamber box girder bridge - Google Patents

Abstract

The invention relates to the field of box girder bridges, in particular to a construction method for quickly dismantling a single-column pier single-box-chamber box girder bridge, which comprises the following steps: blasting demolition construction is carried out on the single-column pier single-box-chamber box girder bridge; the invention discloses a construction method for rapidly dismantling a single-column pier single-box-chamber box girder bridge; the invention realizes blasting demolition of the box girder bridge by a blasting method; the residues formed after the box girder bridge is blasted are reduced as small as possible, so that the subsequent crushing and cleaning of the box girder bridge are facilitated; in addition, the single-column pier dismantling efficiency of the bridge can be accelerated by arranging the positions and the structures of the plurality of filling holes; in the whole process, only the blasting and crushing clearing stages need to be closed, so that the influence of the bridge dismantling process on the society can be reduced.

Description

A construction method for rapid dismantling of a single-column pier single-box-chamber box-girder bridge

technical field

The invention relates to the field of box girder bridges, in particular to a construction method for rapid dismantling of a single column pier single box chamber box girder bridge.

Background technique

With the continuous construction of infrastructure in my country, cast-in-place box girder bridges with single-column piers have been gradually eliminated in the form of high-span high-speed bridges, and the existing bridges need to be demolished, but the demolition work has the following problems: (1) The use of mechanical The problem of symmetrical and synchronous release of prestress in the original continuous box girder could not be solved by dismantling, and the original continuous box girder body had the safety risk of sideways overturning during the dismantling process; (2) The requirement for the time of expressway breaking is very high, and no long time is allowed. (3) The welding position of the beam plate and the pier of the bridge is not easy to separate, and the beam plate is thick and the weight is too large, and the lifting conditions are not available.

To sum up, considering the social and economic benefits, it is particularly important to research and invent a construction method for rapid dismantling of a single-column pier and single-box-chamber cast-in-situ box girder bridge.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, and to provide a construction method for rapidly dismantling a single-column pier single-box-chamber box-girder bridge.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A construction method for rapid dismantling of a single-column pier single-box-chamber box-girder bridge, the construction method comprising the following steps:

The blasting demolition of the single-column pier and single-box-chamber box-girder bridge was carried out.

The blasting demolition construction includes the following steps:

Step 1: open a construction slot on the top deck of the box girder in the box girder bridge; the construction slot is communicated with the inside of the box girder;

Step 2: Open internal filling holes inside the corresponding box girder through each construction slot; open upper filling holes on the bridge deck at the top of the box girder; open side filling holes on the edge guardrail of the box girder bridge;

Step 3: Open lower filling holes on the piers of the box girder bridge;

Step 4: After the completion of step 3, the upper filling hole, the inner filling hole and the side filling hole are respectively filled with explosives;

Step 5: After the completion of Step 4, detonate explosives according to the design requirements to carry out the blasting and dismantling of the box girder bridge; after the blasting is completed, carry out the residue removal and transportation treatment of the box girder bridge after the inspection is completed;

Step 6: After step 5 is completed, the dismantling operation of one box girder bridge is completed. If it is necessary to repeat the dismantling of other box girder bridges, repeat the above steps 1-5.

When drilling the bridge deck at the top of the box girder, the drill bit is required to feed in the direction perpendicular to the bridge deck at the top of the box girder; when drilling the bridge pier, the drill bit is also required to be fed in the direction perpendicular to the centerline of the bridge pier.

The depth of the upper filling holes opened in the middle area of the bridge deck at the top of the box girder is smaller than the depth of the upper filling holes opened in the areas on both sides of the bridge deck at the top of the box girder.

The edge guardrail is provided with a plurality of side filling holes, and the plurality of the side filling holes are distributed in a dislocation; each of the side filling holes is distributed in a plum blossom shape.

The upper filling holes are all rectangular holes; each of the upper filling holes is distributed in a rectangular shape.

The bridge pier is provided with a plurality of lower filling holes; the plurality of lower filling holes are distributed in a dislocation, and each of the lower filling holes is distributed in a plum blossom shape.

The lower filling hole on the bridge pier is located in the middle area of the bridge pier; the upper end and the lower end of the bridge pier are reserved with blank sections.

The side filling holes are arranged obliquely.

The inner filling holes include bottom filling holes arranged at the bottom of the box girder and side filling holes arranged on the side walls of the box girder; the depth of the side filling holes is greater than the depth of the bottom filling holes; the side filling holes are arranged obliquely .

The advantages of the present invention are:

The invention discloses a construction method for rapid dismantling of a single-column pier single-box-chamber box girder bridge; the invention realizes the blasting dismantling of the box girder bridge through the blasting method; the residue formed after the blasting of the box girder bridge is as small as possible, It is convenient for the subsequent crushing, clearing and transportation of the box girder bridge; in addition, the present invention can speed up the dismantling efficiency of the single-column pier of the bridge through the arrangement of multiple filling hole positions and structures; the whole process only needs to close the traffic during the blasting and crushing clearing and transportation stages, which can reduce the demolition of the bridge. The impact of the process on society.

Description of drawings

Below is a brief description of the content expressed in each of the drawings in the description of the present invention and the labels in the drawings:

FIG. 1 is a top view of the bridge deck at the top of the box girder in the present invention.

2 is a cross-sectional view of the present invention with an upper skylight hole.

FIG. 3 is a cross-sectional view of the present invention with an internal filling hole.

FIG. 4 is a front view of a bridge pier with a lower filling hole in the present invention.

The marks in the above figure are:

1. Bridge pier, 2. Box girder, 3. Top deck of box girder, 4. Edge guardrail.

Detailed ways

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and through the description of the preferred embodiments.

A construction method for rapid dismantling of a single-column pier, single-box-chamber box-girder bridge 2-1, the construction method comprising the following steps: blasting and dismantling a single-column pier, single-box-chamber box-girder bridge 2-1; the invention discloses a The construction method for the rapid demolition of the box girder bridge 2-1 with a single column pier and a single box chamber; the present invention realizes the demolition of the box girder bridge 2-1 by blasting; The solution is small, which is convenient for the subsequent crushing and transportation of box girder bridge 2-1.

Further, the blasting demolition construction described in the present invention comprises the following steps:

Step 1: A construction slot 3-1 is set on the deck 3 at the top of the box girder in the box girder bridge 2-1; the construction slot 3-1 is communicated with the inside of the box girder 2;

Step 2: Open internal filling holes 22 in the corresponding box girder 2 through each construction slot 3-1; open upper filling holes 31 on the deck 3 at the top of the box girder; open on the edge guardrail 4 of the box girder bridge 2-1 side filling hole 41;

Step 3: Open the lower filling hole 11 on the pier 1 of the box girder bridge 2-1;

Step 4: After the completion of step 3, the upper filling hole 31, the inner filling hole 22 and the side filling hole 41 are respectively filled with explosives;

Step 5: After the completion of step 4, detonate explosives according to the design requirements to carry out the blasting and dismantling of the box girder bridge 2-1; after the blasting is completed, carry out the residue removal and transportation treatment of the box girder bridge 2-1 after the inspection is completed;

Step 6: After Step 5 is completed, the dismantling operation of one box girder bridge 2-1 is completed. If it is necessary to repeatedly dismantle other box girder bridges 2-1, repeat the above steps 1-5.

The present invention can facilitate the blasting and dismantling of the box girder bridge 2-1 through the disclosure of the above blasting and dismantling construction steps, and simultaneously reduce the particle size of the residue after blasting the box girder bridge 2-1.

In addition, in step 2 of the present invention, it is required to first open the inner filling hole 22; then open the upper filling hole 31 on the top deck 3 of the box girder, and then open the side filling hole 41 on the edge guardrail 4 of the box girder bridge 2-1 Here, the construction sequence is as above, which is to reduce the damage of the slotting to the construction personnel, because if the upper filling hole 31 is opened first, and then the inner filling hole is opened, the dust formed by the upper filling hole 31 will affect the slotting personnel of the subsequent inner filling hole 22. , causing the grooving personnel to absorb too much dust and affect their health.

Further, in the present invention, when drilling the top deck 3 of the box girder, the drill bit is required to feed in the direction perpendicular to the deck 3 at the top of the box girder; when the bridge pier 1 is drilled, the drill bit is also required to be perpendicular to the centerline of the bridge pier 1. Direction feeding, using the above-mentioned operation method, vertical holes can be formed on the bridge deck and pier at the top of the box girder. Compared with the inclined holes, the vertical holes are easier to open. In addition, in the present invention, the above-mentioned upper filling holes 31 , the lower filling hole 11, the bottom filling hole 221 and other filling holes are mainly used to load gunpowder, that is, to load the blasting gun body. In actual use, the above-mentioned filling holes are called blastholes; in the present invention, the blastholes are opened by the above-mentioned operation method, so that Drilling is easier, and the drilling accuracy is high. The size of the blasthole is consistent inside and outside. At the same time, the minimum resistance line of adjacent blastholes is also consistent inside and outside, so that the blasted ore blocks are uniform and will not be thrown too far. , the blasting heap is concentrated near the working face; it is conducive to rock loading.

Further, in the present invention, the depth of the upper filling holes 31 opened in the middle area of the box girder top deck 3 is less than the depth of the upper filling holes 31 opened in the areas on both sides of the box girder top deck 3; The thickness of the upper part of the middle part is smaller than the thickness of the upper part of the edge of the bridge deck. In order to achieve the same blasting effect, the depth of the upper filling hole 31 in the middle part of the bridge deck should be smaller than the depth of the upper filling hole 31 at the edge of the bridge deck, so that the explosive energy of the explosive loaded in the blast hole can be reduced. Equivalent to the energy required to destroy the medium around the hole; optimize the blasting effect.

Further, in the present invention, the edge guard 4 is provided with a plurality of side filling holes 41, and the plurality of the side filling holes 41 are dislocated and distributed; each of the side filling holes 41 is distributed in a plum blossom shape; the energy generated from blasting From the point of view of uniform distribution, the plum-shaped arrangement is more ideal, that is, by adopting the above distribution method, the flying stones generated by the blasting edge guardrail can be less and closer.

Further, in the present invention, the upper filling holes 31 are all rectangular holes; each of the upper filling holes 31 is distributed in a rectangular shape; in the present invention, the construction preparation time is short, in order to ensure that the blasting work is completed within the specified time, it is After considering the blasting effect and preparation time, the rectangular hole arrangement has the advantages of easier and more accurate positioning, fewer drilling rig movements, and shorter construction preparation time. Therefore, the rectangular hole arrangement is selected.

Further, in the present invention, the bridge pier 1 is provided with a plurality of lower filling holes 11; the plurality of lower filling holes 11 are dislocated and distributed, and each of the lower filling holes 11 is distributed in a plum blossom shape, and adopts a plum blossom arrangement and "More holes, less charge" makes the total charge dispersed, the single hole charge is micro-quantified, combined with the multi-stage differential blasting technology, the breaking speed is more uniform, the blasting vibration and shock wave damage and the ground-contact vibration after the bridge collapses are smaller. .

Further, in the present invention, the lower filling hole 11 on the bridge pier 1 is located in the middle area of the bridge pier 1; the upper end and the lower end of the bridge pier 1 are reserved with blank sections 12; Combined with the surrounding construction environment, the design scheme of in-situ collapse is adopted; Then, the position and height of the blasting incision are determined in combination with the "instability principle"; when the upper and lower parts of the bridge are simultaneously blasted and demolished, the blank section 12 can absorb excess energy by blasting in the middle of the pier 1, so that there is no excess energy to cause flying stones, It can only collapse in situ; if holes are opened at the upper and lower ends of pier 1, the energy generated by blasting will be greater than the energy required for the medium around the hole to achieve the expected blasting effect, and the medium structure will be destroyed. Harmful effects such as flying objects and earthquakes have an impact on the surrounding geology and buildings.

Further, in the present invention, the side filling holes 41 are arranged obliquely; such arrangement facilitates the placement of explosives and prevents the explosives from falling.

Further, in the present invention, the inner filling hole 22 includes a bottom filling hole 221 arranged at the bottom of the box girder 2 and a side filling hole 222 arranged on the side wall of the box girder 2; the edge filling hole 222 has a depth greater than The depth of the bottom filling hole 221; this arrangement can ensure that the side wall of the box girder is separated from the bottom of the box girder, so as to avoid the production of large pieces of flying rock at the bottom of the box girder after blasting, which will affect subsequent cleaning operations; in addition, in the present invention, the edge filling The holes 222 are arranged obliquely; this arrangement facilitates the placement of explosives and prevents the explosives from falling.

When implementing:

By analyzing the force of 2-1 of the cast-in-situ box-girder bridge with single-column pier and single-box chamber, summarizing and optimizing the blasting construction network, not only can the prestress of the cast-in-place box girder 2 girder slabs be safely released by blasting, but also the single column of the bridge can be safely released. The piers play the role of simultaneous demolition and speeding up the construction progress, thereby saving time and cost and improving economic and social benefits.

The main implementation process includes the following aspects:

Several construction notches 3-1 are cut on the bridge deck 3 at the top of the box girder, so that the operator can enter the inside of the box girder 2; it is convenient for the subsequent use of the bridge deck to arrange holes and charge the bottom of the box girder 2 to enhance the blasting effect and reduce the slag cleaning time. , compared to arranging holes at the bottom of the box girder 2 at the bottom of the bridge, it saves the time for erecting supports;

In addition, in the present invention, the bridge deck drilling adopts a vertical drilling method, wherein the depth of the bridge deck drilling on both sides of the box girder 2 is 0.35m, the two sides of the edge guardrail 4 adopt plum-shaped holes, and the rest adopt rectangular holes;

The pier 1 is drilled vertically, leaving 1m above and below each without drilling, and using plum-shaped holes;

Afterwards, blasting and crushing and cleaning are carried out as required.

The advantages of the present invention are:

The design of blasting holes on the plane and longitudinal plane of the cast-in-situ box girder 2 of the single box chamber is used to make the box girder 2 as small as possible after blasting, so as to facilitate the crushing and transportation; , to speed up the demolition efficiency of the bridge single-column pier; the whole process only needs to close the traffic in the blasting and crushing clearing stage, which can reduce the impact of the bridge demolition process on the society.

Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner, as long as various insubstantial improvements made by adopting the method concept and technical solution of the present invention are all within the protection scope of the present invention.

Claims (10)

1. A construction method for rapidly dismantling a single-column pier single-box chamber box girder bridge is characterized by comprising the following steps:

and blasting and dismantling the single-column pier single-box-chamber box girder bridge.

2. The construction method for rapidly dismantling the single-pier single-box girder bridge according to claim 1,

the blasting demolition construction comprises the following steps:

step 1: a construction notch is formed in a bridge floor at the top of a box girder in the box girder bridge; the construction notch is communicated with the interior of the box girder;

step 2: forming internal filling holes in the corresponding box girders through each construction notch; an upper filling hole is formed in the bridge floor at the top of the box girder; side face filling holes are formed in edge guardrails of the box girder bridge;

and step 3: arranging lower filling holes on piers of the box girder bridge;

and 4, step 4: after the step 3 is finished, filling explosives in the upper filling hole, the inner filling hole and the side filling hole respectively;

and 5: after the step 4 is finished, detonating explosives according to design requirements to demolish the box girder bridge; after blasting is finished, carrying out residue cleaning treatment on the box girder bridge after inspection is finished;

step 6: and (5) after the step 5 is finished, finishing the dismantling operation of one box girder bridge, and repeating the steps 1-5 if other box girder bridges need to be dismantled repeatedly.

3. The construction method for rapidly dismantling the single-column-pier single-box-chamber box girder bridge according to claim 2, wherein when the box girder top deck is drilled, a drill bit is required to feed in a direction vertical to the box girder top deck; the pier drilling also requires that the drill bit is fed along the direction vertical to the center line of the pier.

4. The construction method for rapidly dismantling the single box girder bridge with single column piers according to claim 2, wherein the depth of the upper filling hole formed in the middle area of the top deck of the box girder is smaller than the depth of the upper filling hole formed in the two side areas of the top deck of the box girder.

5. The construction method for rapidly dismantling the single-column-pier single-box-chamber box girder bridge according to claim 2, wherein a plurality of side face filling holes are formed in the edge guardrail and are distributed in a staggered manner; each side surface filling hole is distributed in a plum blossom shape.

6. The construction method for rapidly dismantling the single-pier single-box-chamber box girder bridge according to claim 2, wherein the upper filling holes are all rectangular holes; each upper filling hole is distributed in a rectangular shape.

7. The construction method for rapidly dismantling the single-column-pier single-chamber box girder bridge according to claim 2, wherein a plurality of lower filling holes are formed in the pier; the lower filling holes are distributed in a staggered mode, and the lower filling holes are distributed in a plum blossom shape.

8. The construction method for rapidly dismantling the single-column-pier single-box-chamber box girder bridge according to claim 2, wherein a lower filling hole on the bridge pier is arranged in the middle area of the bridge pier; blank sections are reserved at the upper end and the lower end of the pier.

9. The construction method for rapidly dismantling the single-pier single-box girder bridge according to claim 5, wherein the side filling holes are obliquely arranged.

10. The construction method for rapidly dismantling the single-pier single-box girder bridge according to claim 2, wherein the internal filling holes comprise bottom filling holes formed in the bottom of the box girder and side filling holes formed in the side walls of the box girder; the depth of the edge filling hole is greater than that of the bottom filling hole; the edge filling holes are arranged obliquely.

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