CN105973082B - The bore distribution method of reinforced concrete brace demolition blasting in a kind of foundation ditch - Google Patents

Abstract

The invention relates to a hole layout method for blasting demolition of a reinforced concrete support beam in a foundation pit. The technical solution is: an arc-shaped tube group (1) is pre-embedded in the reinforced concrete support beam (3) in the foundation pit along the longitudinal direction, and the arc-shaped tubes in the arc-shaped tube group (1) are 1 or 3 , the nozzles at both ends of each arc-shaped tube are upward, the straight-line distance between the two ends of the nozzles L=1800~2300mm, the center line of the same-end nozzles of each arc-shaped tube in the arc-shaped tube group (1) perpendicular to the long side of the reinforced concrete support beam (3). Two straight pipes (2) are pre-buried in the middle of the arc pipe groups (1), each straight pipe (2) is perpendicular to the upper plane of the reinforced concrete support beam (3), each straight pipe (2 ) The distance between the upper end nozzle and the upper end nozzle of the adjacent arc tubes on both sides is equal. The invention has the characteristics of convenient construction, short construction period, low cost, can improve the safety and reliability of blasting demolition, and can enhance the effect of blasting demolition.

Description

A Hole Distribution Method for Blasting Demolition of Reinforced Concrete Support Beams in Foundation Pit

technical field

The invention belongs to the technical field of hole layout for blasting demolition of reinforced concrete support beams. In particular, it relates to a hole layout method for blasting demolition of reinforced concrete support beams in foundation pits.

Background technique

With the development of construction technology, various large deep foundation pits have increased, and the amount of reinforced concrete support beams in the foundation pits has gradually increased. The currently used demolition methods mainly include: blasting demolition method, mechanical demolition method and manual chisel removal method. Compared with the latter two demolition methods, the blasting demolition method has the characteristics of short demolition period, fast slag discharge, recyclable waste steel bars and resource saving, so it is currently the most widely used in the demolition of reinforced concrete support beams.

The blasting demolition method is usually to prefabricate vertical blastholes in the process of pouring reinforced concrete support beams. When demolishing, explosives are buried in the prefabricated vertical blastholes of reinforced concrete support beams, and the demolition is carried out by blasting and fragmentation. This method of vertically arranging the blastholes along the longitudinal direction of the reinforced concrete support beam increases the number of prefabricated blastholes and the workload of hole layout, which usually prolongs the construction period and increases the cost of demolition by blasting; and due to the size factor of the reinforced concrete support beam section The depth of the blast hole is limited, often resulting in a small amount of single-hole explosive or insufficient plugging length of the blast hole, resulting in insufficient blasting and fragmentation of the reinforced concrete support beam or the occurrence of blasting incidents, increasing the cost of mechanical secondary crushing and demolition.

Contents of the invention

The present invention aims to overcome the disadvantages of the prior art. The purpose is to provide a hole layout method for blasting demolition of reinforced concrete support beams in foundation pits which is convenient in construction, short in construction period, low in cost, can improve the safety and reliability of blasting demolition, and can enhance the effect of blasting demolition.

In order to achieve the above tasks, the technical solution adopted by the present invention is: before the reinforced concrete support beam in the foundation pit is poured, an arc-shaped tube group is pre-embedded in the reinforced concrete support beam in the foundation pit along the longitudinal direction, and each arc-shaped tube group The planes formed by the arc-shaped tubes are all parallel to the side of the reinforced concrete support beam, the nozzles at both ends of each arc-shaped pipe are upward, and the straight-line distance between the two ends of the nozzles is L=1800～2300mm; The horizontal line connecting the centers of the nozzles at the same end of each arc-shaped pipe is perpendicular to the long side of the reinforced concrete support beam.

The distance between the arc tube groups r=0.38H～0.42H.

Two straight pipes are pre-embedded in the middle of the arc-shaped pipe groups, each straight pipe is perpendicular to the upper plane of the reinforced concrete support beam, and the upper end of each straight pipe is connected to the upper end of the adjacent arc-shaped pipes on both sides. The distance is equal, the upper end of each straight pipe is flush with the two ends of the arc pipe group, and they are all 40-60mm higher than the upper plane of the reinforced concrete support beam.

The pre-embedded number of the arc tube group is: a) when the width R of the reinforced concrete support beam is less than 700mm, the arc tube is arranged as a single piece in the reinforced concrete support beam; b) when the width R of the reinforced concrete support beam When it is greater than or equal to 700mm, the arc tubes are arranged in three in the reinforced concrete support beam, and the distance between the arc tubes on both sides of the middle arc tube is a=0.35R～0.4R.

The radius of curvature ρ1 _of the middle arc tube when the arc tube group is arranged in three

The radius of curvature _ρ2 of the arc tubes on both sides when the arc tube group is three arranged or a single arc tube

In formula (i) and formula (ii): L represents the linear distance between the two ends of the arc tube, mm;

H represents the height of the reinforced concrete support beam, mm.

The arc tubes in the arc tube group are made of PVC, and the diameter of each arc tube is 40-50mm.

The distance between the lower port of the straight pipe and the lower surface of the reinforced concrete support beam is 2H/9-3H/9; the material of the straight pipe is PVC, and the diameter of the straight pipe is 40-50mm.

Owing to adopting above-mentioned technical scheme, the present invention has following positive effect compared with prior art:

In the present invention, before the reinforced concrete support beam 3 is poured, arc-shaped tube groups 1 with different curvature radii are pre-buried along the longitudinal direction of the reinforced concrete support beam 3, and arc-shaped tubes 1 perpendicular to the steel bars are arranged between adjacent arc-shaped tube groups 1. The horizontal straight pipe 2 on the plane of the concrete support beam 3, the arc pipe group 1 and the straight pipe 2 are prefabricated blastholes. The coordinated arrangement of the pre-buried arc tube group 1 and the straight tube 2 makes the energy after the explosion of the explosives in each prefabricated blasthole coupled to each other, makes the explosion load distribution in the reinforced concrete support beam 3 more uniform, and can effectively avoid The entity of the reinforced concrete support beam 3 is excessively crushed or insufficiently crushed, and the like occurs. Moreover, embedding arc-shaped pipes with different curvature radii along the longitudinal direction of the support beam can greatly reduce the number of embedding vertical blastholes, reduce construction costs, shorten the construction period, and enhance the effect of blasting demolition.

The invention can greatly reduce the number of pre-embedded blastholes and the material cost of the prefabricated blastholes for demolition of the reinforced concrete support beam 3; can effectively avoid the occurrence probability of blasting incidents, and reduce the safety threat to the surrounding environment; make the reinforced concrete support beam 3 The blasting is fully broken, which can effectively shorten the construction period of blasting demolition and improve economic benefits. The invention is not only applicable to the blasting demolition of reinforced concrete support beams in foundation pits, but also can be widely used in blasting demolition projects such as frame structure buildings, factory buildings and viaducts.

Therefore, the present invention has the characteristics of convenient construction, short construction period, low cost, improved safety and reliability of blasting demolition, and enhanced effect of blasting demolition.

Description of drawings

Fig. 1 is the top view of a kind of method for laying holes of the present invention;

FIG. 2 is a schematic cross-sectional view of the A-A step section in FIG. 1 .

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, which is not intended to limit its protection scope.

Example 1

The invention discloses a hole layout method for the blasting demolition of reinforced concrete support beams in foundation pits. The size of the cross-section of the reinforced concrete support beam in the foundation pit described in this embodiment is: the width R is 800 mm; the height H is 600 mm.

The hole layout method described in this embodiment is shown in Figure 1 and Figure 2: before the reinforced concrete support beam 3 in the foundation pit is poured, an arc-shaped pipe group 1 is pre-embedded in the reinforced concrete support beam 3 in the foundation pit along the longitudinal direction, The plane formed by each arc tube in the arc tube group 1 is parallel to the side of the reinforced concrete support beam 3, the nozzles at both ends of each arc tube are upward, and the straight-line distance between the two ends L=2000mm ; The line connecting the centers of the nozzles at the same end of each arc tube in the arc tube group 1 is perpendicular to the long side of the reinforced concrete support beam 3 .

As shown in Figure 1: the distance between arc tube groups 1 r=0.38H～0.42H

＝(0.38～0.42)×600mm

=228~252mm.

As shown in Figure 1 and Figure 2: 2 straight pipes are pre-buried in the middle of the arc pipe group 1, each straight pipe 2 is perpendicular to the upper plane of the reinforced concrete support beam 3, and each straight pipe 2 upper end pipe The distance between the mouth and the upper end of the adjacent arc tubes on both sides is equal, the upper end of each straight pipe 2 is flush with the two ends of the arc tube group 1, and they are all 40mm higher than the upper plane of the reinforced concrete support beam 3 .

As shown in FIG. 1 , the pre-embedded number of the arc tube group 1 is: since the width R=800mm of the reinforced concrete support beam 3 is greater than 700mm, three arc tubes are arranged on the reinforced concrete support beam 3 .

As shown in Figures 1 and 2, the distance a between the nozzles of the curved tubes on both sides when the arc tube group 1 is arranged in three

a=(0.35～0.4)×R

＝(0.35～0.4)×800

=280~320mm.

As shown in Fig. 1 and Fig. 2, the radius of curvature ρ ₁ of the middle arc tube when the said arc tube group 1 is three arranged

As shown in Figures 1 and 2, the radius of curvature _p2 of the arc tubes on both sides when the arc tube group 1 is three arranged

In formula (i) and formula (ii): L represents the linear distance between the two ends of the arc tube, mm;

H represents the height of the reinforced concrete support beam 3, mm.

Substitute L=2000mm and H=600mm into formula (i) and formula (ii) respectively, then

ρ ₁ =2203mm;

ρ ₂ =1450 mm.

The material of the arc tubes in the arc tube group 1 is PVC, and the aperture of each arc tube is 40mm.

The distance between the lower port of the straight pipe 2 and the lower surface of the reinforced concrete support beam 3 is 2H/9～3H/9=600(2/9～3/9)=133～200mm; the material of the straight pipe 2 is PVC, the hole diameter of the straight pipe 2 is 40mm.

Example 2

The invention discloses a hole layout method for the blasting demolition of reinforced concrete support beams in foundation pits. The size of the cross-section of the reinforced concrete support beam in the foundation pit described in this embodiment is: the width R is 1000mm; the height H is 800mm.

The hole layout method described in this embodiment is shown in Figure 1 and Figure 2: before the reinforced concrete support beam 3 in the foundation pit is poured, an arc-shaped pipe group 1 is pre-embedded in the reinforced concrete support beam 3 in the foundation pit along the longitudinal direction, The plane formed by each arc tube in the arc tube group 1 is parallel to the side of the reinforced concrete support beam 3, the nozzles at both ends of each arc tube are upward, and the straight-line distance between the two ends L=2300mm ; The line connecting the centers of the nozzles at the same end of each arc tube in the arc tube group 1 is perpendicular to the long side of the reinforced concrete support beam 3 .

It is located at the intersection line between the upper plane of the reinforced concrete support beam 3 and the corresponding cross section.

As shown in Figure 1, the distance r=(0.38～0.42)H between arc tube groups 1

＝(0.38～0.42)×800mm

=304~336mm.

As shown in Figure 1 and Figure 2: 2 straight pipes are pre-buried in the middle of the arc pipe group 1, each straight pipe 2 is perpendicular to the upper plane of the reinforced concrete support beam 3, and each straight pipe 2 upper end pipe The distance between the mouth and the upper end of the adjacent arc tubes on both sides is equal, the upper end of each straight pipe 2 is flush with the two ends of the arc tube group 1, and they are all 50mm higher than the upper plane of the reinforced concrete support beam 3 .

As shown in Fig. 1, the pre-embedded number of the arc tube group 1 is: since the width R=1000mm of the reinforced concrete support beam 3 is greater than 700mm, three arc tubes are arranged in the reinforced concrete support beam 3.

As shown in Figures 1 and 2, the arc tube group 1 is the distance a between the nozzles of three arc tubes arranged on both sides

a=0.35R～0.4R

＝(0.35～0.4)×1000

=350~400mm.

As shown in Figures 1 and 2, the arc tube group ₁ is the radius of curvature ρ1 of the middle arc tubes in the arrangement of three

As shown in Figures 1 and 2, the arc tube group 1 is the curvature radius ρ2 of the arc tubes on both sides in the arrangement of _three

In formula (i) and formula (ii): L represents the linear distance between the two ends of the arc tube, mm;

H represents the height of the reinforced concrete support beam 3, mm.

Substitute L=2300mm and H=800mm into formula (i) and formula (ii) respectively, then

ρ ₁ =2226mm;

ρ ₂ =1506mm.

The arc tubes in the arc tube group 1 are made of PVC, and the aperture of each arc tube is 50 mm.

The distance between the lower port of the straight pipe 2 and the lower surface of the reinforced concrete support beam 3 is 2H/9～3H/9=800(2/9～3/9)=178～267; the material of the straight pipe 2 is PVC, the hole diameter of the straight pipe 2 is 50mm.

Example 3

The invention discloses a hole layout method for the blasting demolition of reinforced concrete support beams in foundation pits. The size of the cross-section of the reinforced concrete support beam in the foundation pit described in this embodiment is: the width R is 600mm; the height H is 400mm.

The hole layout method described in this embodiment is: before the reinforced concrete support beam 3 in the foundation pit is poured, an arc-shaped tube group 1 is pre-embedded in the reinforced concrete support beam 3 in the foundation pit along the longitudinal direction, and the arc-shaped tube group 1 The plane formed by each arc-shaped tube is parallel to the side of the reinforced concrete support beam 3, the two ends of each arc-shaped tube are upward, and the straight-line distance between the two ends of the tube is L=1800mm; the arc-shaped tube group 1 The line connecting the centers of the nozzles at the same end of each arc-shaped pipe is perpendicular to the long side of the reinforced concrete support beam 3.

As shown in Figure 1, the distance between arc tube groups 1 r=0.38H～0.42H

＝(0.38～0.42)×400mm

=152~168mm.

As shown in Figure 1: two straight pipes are pre-buried in the middle of the arc pipe group 1, each straight pipe 2 is perpendicular to the upper plane of the reinforced concrete support beam 3, and the upper end of each straight pipe 2 is connected to the two The distances between the upper end nozzles of the adjacent arc tubes are equal, and the upper end nozzles of each straight pipe 2 are flush with the two ends of the arc tube group 1, and are all higher than the reinforced concrete support beam 3 upper plane 60mm.

The pre-embedded number of the arc tube group 1 is: when the width R=600 of the reinforced concrete support beam 3 is less than 700 mm, the arc tubes are arranged as a single piece in the reinforced concrete support beam 3 .

The radius of curvature ρ of the single arranged arc tube

In formula (ⅰ): L represents the linear distance between the two ends of the arc tube, mm;

H represents the height of the reinforced concrete support beam 3, mm.

Substitute L=1800mm and H=400mm into formula (i), then

ρ=1652mm.

The material of the single arc tube is PVC, and the aperture of each arc tube is 40mm.

The distance between the lower port of the straight pipe 2 and the lower surface of the reinforced concrete support beam 3 is 2H/9～3H/9=400(2/9～3/9)=130; the material of the straight pipe 2 is PVC, The diameter of the straight pipe 2 is 40mm.

Compared with the prior art, this specific embodiment has the following positive effects:

In this specific embodiment, before the reinforced concrete support beam 3 is poured, arc-shaped tube groups 1 with different curvature radii are pre-buried along the longitudinal direction of the reinforced concrete support beam 3, and vertical The horizontal straight pipe 2 on the plane of the reinforced concrete support beam 3, the arc pipe group 1 and the straight pipe 2 are prefabricated blastholes. The coordinated arrangement of the pre-buried arc tube group 1 and the straight tube 2 makes the energy after the explosion of the explosives in each prefabricated blasthole coupled to each other, makes the explosion load distribution in the reinforced concrete support beam 3 more uniform, and can effectively avoid The entity of the reinforced concrete support beam 3 is excessively crushed or insufficiently crushed, and the like occurs. Moreover, embedding arc-shaped pipes with different curvature radii along the longitudinal direction of the support beam can greatly reduce the number of embedding vertical blastholes, reduce construction costs, shorten the construction period, and enhance the effect of blasting demolition.

This specific embodiment can significantly reduce the number of pre-embedded blastholes and the material cost of prefabricated blastholes for demolition of the reinforced concrete support beam 3; it can effectively avoid the probability of blasting incidents, and reduce the security threat to the surrounding environment; make the reinforced concrete support Beam 3 is sufficiently broken by blasting, which can effectively shorten the construction period of blasting demolition and improve economic benefits. This specific embodiment is not only applicable to the blasting demolition of reinforced concrete support beams in foundation pits, but also can be widely used in blasting demolition projects such as frame structure buildings, factory buildings and viaducts.

Therefore, this specific embodiment has the characteristics of convenient construction, short construction period, low cost, and can improve the safety and reliability of blasting demolition and can enhance the effect of blasting demolition.

Claims (3)

1. the bore distribution method of reinforced concrete brace demolition blasting in a kind of foundation ditch, it is characterised in that the bore distribution method is： Before reinforced concrete brace (3) is poured, curved pipe group is embedded with along the longitudinal direction in the reinforced concrete brace (3) (1) side of the plane that, every curved pipe in curved pipe group (1) is constituted each parallel to the reinforced concrete brace (3) Face, the two ends mouth of pipe of every curved pipe is upward, air line distance L=1800~2300mm between the mouth of pipe of two ends；In curved pipe group (1) Every curved pipe same end pipe mouthful the line of centres perpendicular to the long side of reinforced concrete brace (3)；

Between curved pipe group (1) apart from r=0.38H~0.42H, H represents the height of reinforced concrete brace (3), mm；

Middle position between curved pipe group (1) is embedded with 2 straight tubes, and every straight tube (2) is perpendicular to reinforced concrete brace (3) upper plane, every straight tube (2) the upper end mouth of pipe is equal with the distance for the curved pipe upper end mouth of pipe that both sides are neighbouring, every straight tube (2) the upper end mouth of pipe is concordant with the two ends mouth of pipe of curved pipe group (1), be higher by plane 40 on reinforced concrete brace (3)~ 60mm；

The pre-buried number of the curved pipe group (1) is：A) when the width R of reinforced concrete brace (3) is less than 700mm, arc Pipe is single arrangement in reinforced concrete brace (3)；B) when the width R of reinforced concrete brace (3) is more than or equal to During 700mm, curved pipe is 3 arrangements, the curved pipe mouth of pipe spacing of medial arc pipe both sides in reinforced concrete brace (3) A=0.35R~0.4R.

2. according to claim 1 in foundation ditch reinforced concrete brace demolition blasting bore distribution method, it is characterised in that institute The radius of curvature ρ of medial arc pipe when stating curved pipe group (1) for 3 arrangements₁

<mrow> <msub> <mi>&amp;rho;</mi> <mn>1</mn> </msub> <mo>=</mo> <mfrac> <mrow> <mn>5</mn> <msup> <mi>L</mi> <mn>2</mn> </msup> </mrow> <mrow> <mn>16</mn> <mi>H</mi> </mrow> </mfrac> <mo>+</mo> <mfrac> <mi>H</mi> <mn>5</mn> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mi>i</mi> <mo>)</mo> </mrow> </mrow>

The radius of curvature ρ of both sides curved pipe when the curved pipe group (1) is 3 arrangements or curved pipe when being single arrangement₂

<mrow> <msub> <mi>&amp;rho;</mi> <mn>2</mn> </msub> <mo>=</mo> <mfrac> <mrow> <mn>3</mn> <msup> <mi>L</mi> <mn>2</mn> </msup> </mrow> <mrow> <mn>16</mn> <mi>H</mi> </mrow> </mfrac> <mo>+</mo> <mfrac> <mi>H</mi> <mn>3</mn> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mi>i</mi> <mi>i</mi> <mo>)</mo> </mrow> </mrow>

In formula (I) and formula (II)：L represents the air line distance between the mouth of pipe of curved pipe two ends, mm,

H represents the height of reinforced concrete brace (3), mm；

The curved pipe material of the curved pipe group (1) is PVC, and the aperture of every curved pipe is 40~50mm.

3. according to claim 1 in foundation ditch reinforced concrete brace demolition blasting bore distribution method, it is characterised in that institute It is 2H/9~3H/9 that the lower port of straight tube (2), which is stated, with the distance of reinforced concrete brace (3) lower surface；The straight tube (2) Material is PVC, and the aperture of straight tube (2) is 40~50mm.