CN110714437A

CN110714437A - Construction method for installing and constructing four-foot hollow square blocks of coastal breakwater

Info

Publication number: CN110714437A
Application number: CN201911030963.5A
Authority: CN
Inventors: 高子双; 王久营; 刘杰章; 王建军; 徐鹏远; 于涛
Original assignee: CCCC TDC Yantai Environmental Protection Dredging Co Ltd
Current assignee: CCCC TDC Yantai Environmental Protection Dredging Co Ltd
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2020-01-21

Abstract

The invention relates to a construction method for installing a four-foot hollow square block of a sea-facing breakwater, which comprises the following steps of (1) screening stone materials in situ, throwing and filling block stones with larger grain sizes in construction, and throwing and filling block stones with smaller grain sizes in an upper layer; (2) adopting a marker post wire pulling method to perform block stone slope, calculating the design elevation of a corresponding point of the marker post according to the design section, marking the marker post with red paint, and then performing cushion block stone slope; (3) and marking the position of the stone surface by using RTK (real-time kinematic) in the measurement, directly transferring to a specified position by using a crane for installation, and manually finely adjusting the prefabricated part to fix the position. The method can avoid the operation of vertical putting down, optimize the construction process, reduce the damage to the components and improve the construction efficiency; the plane position of each four-foot hollow block is measured by using RTK before construction, the position of each four-foot hollow block can be determined through the operation, the four-foot hollow block is lifted to a specified position, and the prefabricated part is finely adjusted and fixed manually.

Description

Construction method for installing and constructing four-foot hollow square blocks of coastal breakwater

Technical Field

The invention belongs to the technical field of coastal channel improvement engineering, and particularly relates to a construction method for mounting four-foot hollow blocks of a coastal breakwater.

Background

The hollow square installation of breakwater four feet in the nearly sea channel renovation engineering, especially the installation to the hollow square of 2t four feet, because 100 ~ 150kg cushion piece stone specification below the hollow square of 2t four feet is big, reason slope flatness specification error is at 300mm, be difficult to satisfy the requirement that the adjacent block body difference in height of hollow square installation is not more than 150mm, consequently, higher requirement has been proposed to cushion piece stone reason slope, prior art is difficult to satisfy above-mentioned requirement, in addition, traditional mounting method adopts "C" type hoist construction in the construction of the preceding stage, need adopt 2 workman auxiliary member to keep flat, waste time and energy, damage to the component is also more simultaneously.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a construction method for installing four-foot hollow blocks of a sea-facing breakwater, which comprises the following steps in sequence:

(1) firstly, screening stone materials in situ, wherein the stone materials have small grain size when entering the field, then screening the stone materials, storing the stone materials in two places according to the grain size, throwing and filling the stone materials with larger grain size in the construction process, and throwing and filling the stone materials with smaller grain size on the upper layer; (please provide the specific particle size of the two stones)

(2) Adopting a marker post wire pulling method to perform block stone slope management, specifically arranging marker posts at the top of the block stone slope and every 10m of a side slope, calculating the design elevation of corresponding points of the marker posts according to the design section, marking the marker posts with red paint, pulling a striking red rope between the red paint marks of two adjacent marker posts, so that the plane of the block stone needs to be selected through bucket teeth of an excavator bucket to be exposed outwards, and then using the bucket surface of the excavator bucket to flap the set stone to be flat for bedding the block stone slope management;

(3) the measurement adopts RTK to emit the position of the upper side line and the pile number control point of the ninth four-foot hollow square at the top end of the first group of four-foot hollow squares and the lower side line of the bottommost four-foot hollow square on the stone surface, the position is marked on the flat stone surface by paint, then the position of the slope foot is pulled to the upper side line of the ninth four-foot hollow square at the top end, a red line is tied at the upper side line of each four-foot hollow square, the position of each component is determined according to the position of the red line, then the crane is adopted to directly transfer the components to the specified position for installation, the prefabricated components are manually finely adjusted, and the position is fixed.

Preferably, in the step (3), the four-footed hollow blocks are installed from bottom to top through a crane and a steel wire rope, the four-footed hollow blocks are installed at the slope footers firstly, then the four-footed hollow blocks for slope protection are installed from the first row to top, and finally the four-footed hollow blocks at the top of the slope are installed after the pouring of the retaining wall is completed, wherein the specific installation method comprises the following steps:

(1) transporting the four-foot hollow square blocks to the site by adopting a flat transport vehicle, loading and transporting a plurality of blocks by each vehicle, hoisting the four-foot hollow square blocks by a crane on the site through a hoisting tool and placing the four-foot hollow square blocks on a flat ground to be closely placed;

(2) fixing the four-foot hollow square block on a lifting appliance, lifting the four-foot hollow square block by a crane, and slowly lowering the four-foot hollow square block towards a preset installation position;

(3) placing the four-leg hollow square block at the lowest end according to a preset installation control line on the slope, and pulling two workers at the outer side of the hanger to assist in controlling the falling position when the four-leg hollow square block is 0.5m away from the slope, and lowering the block to a mark position;

(4) after the hollow square block is installed in place, a measurer retests the plane position and the elevation of the hollow square block, if the plane position has deviation, the crane lifts the four-foot hollow square block by about 0.3m, the four-foot hollow square block is adjusted by manually matching with the crane, and if the elevation does not meet the installation requirement, two pieces of stone are filled manually for leveling;

(5) the crane slowly falls down the hanging bracket, and the hanging bracket for fixing the four-foot hollow square blocks is loosened to finish the installation of the group of hollow square blocks.

Preferably in any one of the above schemes, the lifting appliance comprises a fixed plate, two sets of through holes are arranged on the fixed plate, a sleeve is arranged in the through hole, a clamping part is arranged at one end of the sleeve, the clamping part is of a circular structure, the diameter of the clamping part is larger than that of the through hole, a supporting plate is arranged at one end of the clamping part, a rotating rod is arranged on the clamping part, and three sets of lifting holes are arranged on the fixed plate.

In any of the above schemes, preferably, the specific operation of the lifting appliance for lifting and placing the four-foot hollow square blocks is as follows: aligning two sleeves of the lifting appliance to the middle hollow square part of the four-foot hollow square block, after the lifting appliance is placed in the four-foot hollow square block, rotating the sleeves after the sleeves penetrate through the lower surface of the four-foot hollow square block, enabling the supporting plate to clamp the lower surface of the four-foot hollow square block, starting lifting, rotating the sleeves after lifting is completed, taking out the sleeves, and sequentially operating.

In any of the above schemes, preferably, the method for calculating the tonnage of the selected crane comprises the following steps:

a＝arccos(S_max/L)

in the formula: a: hoisting angle under the condition of maximum horizontal distance hoisting;

S_max: a maximum horizontal distance;

primarily selecting a crane according to the weight of a lifted object and the maximum horizontal distance, measuring the arm length L of the crane, calculating the lifting angle a under the lifting condition of the maximum horizontal distance according to the calculation formula, and calculating the lifting angle a according to the a and the S_max comparing the mechanical performance table of the primarily selected crane, checking the load weight of the crane, and determining the load g on the lifting performance table of the crane<When the load weight Q is obtained, the crane must be selected again until Q is more than or equal to g.

In any of the above schemes, preferably, the tonnage calculation method of the crane is:

H_max＝H₁+H₂

H_l＝Lsina

a＝arcsin(H₁/L)

S＝Lcosa

in the formula: h_max: the maximum hoisting height;

H₁: the distance from the fixed pulley of the crane boom rod pulley block to the lower shaft of the suspension arm;

H₂: the distance between the lower shaft of the suspension arm and the ground;

l is the length of the suspension arm;

a, a is a hoisting angle;

s: and horizontally hoisting distance.

When the maximum hoisting height is limited, H_maxThe hoisting angle a and the horizontal distance S can be obtained by the formula, the loading weight g of the crane is checked according to a mechanical performance table of the initially selected crane compared with a and S, and when the hoisting weight q is a known value<And when the weight Q is loaded, the crane is reselected until Q is more than or equal to g.

In any of the above schemes, preferably, the method for calculating the allowable tension of the selected steel wire rope comprises:

[FG]＝AFG/K

in the formula: [ FG ] -allowable tension (KN) of the wire rope;

FG-the sum of wire breaking tensions (KN) of the wire ropes;

a-conversion factor;

k is the safety factor of the steel wire rope.

The invention has the beneficial effects that: according to the method, stones with large grain sizes are paved on the lower layer and stones with small grain sizes are paved on the upper layer by screening stones, a slope is managed by adopting a marker post bracing wire method, and the surface flatness error is controlled within 150 mm; the lifting appliance capable of being directly lifted in parallel is designed, so that the operation of vertically putting down can be avoided, the construction flow is optimized, the damage to components is reduced, and the construction efficiency is improved; the plane position of each hollow square with four feet is measured by using RTK before construction, a marker post is inserted, the upper side line of each block is provided with a red line, the position of each hollow square with four feet can be determined by the operation, the hollow square with four feet is only required to be lifted to a specified position, and the prefabricated part is finely adjusted and fixed in position manually.

Drawings

FIG. 1 is a schematic diagram of a hanger for a construction method for installing four-footed hollow blocks of a sea-facing breakwater according to the present invention;

FIG. 2 is another schematic view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a mounting effect diagram of a four-footed hollow block mounting construction method of the sea-facing breakwater according to the present invention;

fig. 5 is a schematic red line position diagram of a construction method for installing four-footed hollow blocks of the sea-facing breakwater according to the present invention.

The figures are labeled as follows: 1-fixing the plate; 2-lifting a hole; 3-rotating the rod; 4-a sleeve; 5-a supporting plate.

Detailed Description

In order that the invention may be further understood, the invention will now be described in detail with reference to specific examples.

Example one

Determining the tonnage of a crane through calculation

1. Calculated by maximum horizontal distance

The maximum horizontal distance is the horizontal distance from the lower shaft of the boom rod of the crane to the lifting hook, and the maximum horizontal distance S_maxThe method can be determined by the crane station position determined by the actual condition of the construction site, the basic position of equipment, the position of the placed hoisted objects and the like.

cosa＝S_max/L

a＝arccos(S_max/L)

S_max: the maximum horizontal distance.

Primarily selecting a crane according to the weight of a lifted object and the maximum horizontal distance, measuring the arm length L of the crane, calculating the lifting angle a under the lifting condition of the maximum horizontal distance according to the calculation formula, and calculating the lifting angle a according to the a and the S_maxComparing the initially selected mechanical performance table of the crane, checking the load weight of the crane, and determining the load g on the lifting performance table of the crane<When the load weight Q is obtained, the crane must be selected again until the Q is more than or equal to g, and the tonnage of the crane can be calculated by the method.

2. By calculation of maximum hoist height

In practical application, will receive site environment's influence, often the maximum hoist and mount height of crane can receive the restriction, and when the armed lever becomes certain angle with the horizontal plane, just can obtain the maximum hoist and mount height of crane, when satisfying hoist and mount horizontal distance, the maximum height that the lifting hook can reach can obtain following formula:

H_max＝H₁+H₂

H_l＝Lsina

a＝arcsin(H₁/L)

S＝Lcosa

in the formula: h_max: the maximum hoisting height;

l is the length of the suspension arm;

a, a is a hoisting angle;

s: and horizontally hoisting distance.

When the maximum hoisting height is limited, H_maxThe hoisting angle a and the horizontal distance S can be obtained by the formula, the loading weight g of the crane is checked according to a mechanical performance table of the initially selected crane compared with a and S, and when the hoisting weight q is a known value<When the weight Q is loaded, the crane is reselected until Q is more than or equal to g, and the tonnage of the crane can be calculated by the method.

3. Description of the calculation

(1) When the maximum hoisting height is not influenced by the field environment factors, the maximum hoisting height can be determined according to S_maxTo determine the tonnage of the crane, S is needed when the maximum hoisting height is influenced by site environment factors_maxAnd H_maxTwo aspects of the calculation, and the final decision by analysis of the comparison is to use S_maxOr by H_maxThe tonnage of the crane is determined.

(2) When using H_maxWhen determining the tonnage of the crane, the actual distance from the fixed pulley of the crane jib pulley block to the center of the lifting hook is determined according to the actual specification and the lifting point position of a lifted object.

(3) The tonnage of the crane is determined by the two methods, so that the waste of equipment shift in the hoisting construction process due to insufficient construction experience can be avoided, the construction cost is greatly reduced, and the safety and the reliability of the hoisting operation are improved.

4 calculation of wire rope tension

The allowable tension of the steel wire rope is calculated according to the following formula:

[FG]＝AFG/K

in the formula: [ FG ] -allowable tension (KN) of the wire rope;

FG-the sum of wire breaking tensions (KN) of the wire ropes;

a is conversion coefficient, taken according to Table 1;

k is the safety coefficient of the steel wire rope, and is taken according to the table 2.

TABLE 1 wire rope breaking force conversion factor

Steel wire rope structure	Conversion factor
		6×19	0.85
6×37	0.82
		6×61	0.8

TABLE 2 safety factor of the steel wire ropes

In principle, old steel wire ropes are not allowed to be used, and if the old steel wire ropes are used, the allowable tension is obtained by multiplying the old and new degrees of the steel wire ropes by a factor of 0.4-0.75.

Example two

The construction method for installing the four-foot hollow square blocks of the coastal breakwater comprises the following specific steps:

screening stones: firstly, screening stones in situ, wherein the stones have small grain size when entering the field, then screening the stones, storing the stones in two places according to the grain size (120 kg-150 kg of stones and 100 kg-120 kg of stones respectively), firstly throwing and filling stones with large grain sizes in construction, and throwing and filling stones with small grain sizes on the upper layer, thereby providing favorable conditions for follow-up slope management.

Slope management: adopting a marker post line pulling method to perform stone-clearing slope, arranging marker posts at the top of the 100-150 kg stone-clearing slope and every 10m of the side slope, and pulling lines: calculating the design elevation of the corresponding point of the marker post according to the design section, and marking the marker post with red paint: a striking red rope is pulled between two adjacent marker post red paint marks, the grain diameter of 100-150 kg of cushion block stones is large, so that the plane of the block stones needs to be selected through bucket teeth of a bucket of an excavator, the block stones are exposed outwards, then the bucket face of the bucket of the excavator is used for beating to enable the set stones to be flat, and cushion block stone slope management is carried out.

In the process of managing the slope, the excavator walks, the machine bucket beats the action such as stone surface and can shake in different degrees, and the sighting rod that will place is probably shifted to influence the slope quality, so survey crew need carry GPS equipment and look at in real time, guarantee the accuracy of sighting rod red line elevation, if the sighting rod red line position has already shifted, in time rectify, guarantee that surface flatness error is within 150 mm.

Installing four-foot hollow blocks: a surveyor uses RTK to emit the upper side line and the pile number control point position of the ninth block at the top end of the first block and the lower side line position of the hollow square block at the bottom end, the position is marked on the flat stone surface by paint, then the upper side line of the ninth block at the top end is pulled to the upper side line of the ninth block at the slope foot position, a red line (shown in figure 5) is tied at the upper side line of each block, the position of each component is determined according to the red line position, then the crane is directly transported to a specified position for installation, and only manual fine adjustment and fixing of the prefabricated component are needed.

Adopt the mode of from bottom to top installation, at first install four rows at the toe, follow nine blocks of first row upward installation bank protection again, two of last hillside tops wait that the barricade pours the completion after-installation, the concrete scheme is as follows:

(1) transporting the four-foot hollow blocks to the site by adopting a flat transport vehicle, loading 4-5 blocks in each vehicle, hoisting the hoisting blocks by 25t cars on the site to get off the vehicle, and laying the blocks in a group of 10 blocks on the flat ground;

(2) a 25t truck crane lifts a group of four-foot hollow squares, before lifting, whether the connection of a chain block, a steel wire rope, a clamping ring and the like is firm or not is checked, and the blocks are slowly lowered to a preset installation position;

(3) placing a block body at the lowest end according to a preset installation control line on the slope, and pulling 2 workers outside the hanging bracket to assist in controlling the falling position when the block body is 0.5m away from the slope, and lowering the block body to a mark position;

(4) after the hollow square block is installed in place, a measurer retests the plane position and the elevation of the hollow square block, if the plane position has deviation, the height of the crane is about 0.3m, and the crane is manually matched for adjustment; if the elevation does not meet the installation requirement, two pieces of stones are filled manually to be leveled;

(5) the crane slowly falls down the hanging bracket, and the chain block is loosened to finish the installation of the group of hollow blocks (as shown in figure 4).

EXAMPLE III

As shown in figures 1 to 3, the four-foot hollow block is connected by a crane connecting hanger in the hoisting operation of the invention for the four-foot hollow block, wherein the hanger comprises a steel wire rope, a chain block and a hanger, one end of the steel wire rope is connected to the crane, the other end of the steel wire rope is connected with one end of the chain block, the other end of the chain block is connected with the hanger, the lifting appliance comprises a fixing plate 1, two groups of through holes are arranged on the fixing plate 1, sleeves 4 are arranged in the through holes, one end of the sleeve 4 is provided with a clamping part which is of a circular structure, the diameter of the clamping part is larger than that of the through hole, therefore, the sleeve 4 can be clamped in the through hole through a clamping part, a supporting plate 5 is arranged at one end of the sleeve 4 far away from the clamping part, set up dwang 3 in the card portion, set up three lifting holes 2 on the fixed plate 1, the hoist is right the hollow square of four feet lifts by crane and the concrete operation of placing does: will two sleeve pipes 4 of hoist aim at the hollow square part in the middle of the hollow square of four feet, the hoist is after putting into the hollow square of four feet, treat behind sleeve pipe 4 passes the hollow square of four feet below, control dwang 3 is rotatory sleeve pipe 4 makes layer board 5 block below the hollow square of four feet, begin to lift by crane, rotate again after accomplishing the hoist sleeve pipe 4, take out sleeve pipe 4, operate in proper order can.

Example four

Materials and apparatus

TABLE 3 Equipment details

Serial number	Device name	Model number	Number of	Function of
					1	Crawler crane	70 ton of	2 vehicle	Facing block mounting
2	Plate trailer	12.5m long	4 vehicles	Facing block transport
					3	Truck crane	25 ton of	1 vehicle	Facing block mounting
4	RTK	Lycra (Lycra)	1 table	Position of measurement and control

Benefit analysis

Practice proves that after construction is completed, the construction method almost has no damage to the lifting hole and surrounding concrete, but in the traditional lifting process, the steel wire rope can generate larger pressure or damage to the concrete surrounding the lifting hole box. The construction method is flexible, can ensure the apparent quality of the blocks and obtains good quality benefit.

Work efficiency analysis

From the condition of lifting, the lifting process is optimized, 120 blocks can be installed every day when the traditional lifting appliance is used, 150 blocks can be installed every day, the construction efficiency is improved by 25%, and the construction period can be expected to be saved by 12 days. The overall construction progress can be greatly advanced, and meanwhile, the mechanical cost, the labor cost, the management cost and the indirect cost can be greatly saved.

Take Laiyang as an example: the labor cost is about 300 yuan/day, the 25t truck crane cost is 1600 yuan/shift, the crawler crane cost is 2500 yuan/shift, the plate trailer is 300 yuan/shift, and the cost can be saved by 12 days in the construction period as shown in table 4:

TABLE 4 cost-saving watch

Examples of the applications

2t four-leg hollow blocks 8038 are installed in the first exhibition area of the cultural city project of the constant great century by the supply and demand of the artificial beach permanent embankment project of the cigarette platform. In order to reduce the construction cost and shorten the construction period, the traditional block hoisting process is improved, and the construction flow is optimized. The construction efficiency and the quality are obviously improved. By adopting the process, 150 blocks can be installed in each construction team one day, 7600 blocks are completed at present, the installation quality is good, and the collision phenomenon of components is less.

It will be understood by those skilled in the art that the construction method for installing the four-footed hollow block of the sea breakwater according to the present invention includes the above-mentioned summary and detailed description of the invention and any combination of the parts shown in the drawings, which are not described in detail and are not intended to be construed as a brief description of the description. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for installing and constructing a four-foot hollow square block of a coastal breakwater comprises the following steps in sequence:

(1) firstly, screening stone materials in situ, wherein the stone materials have small grain size when entering the field, then screening the stone materials, storing the stone materials in two places according to the grain size, throwing and filling the stone materials with larger grain size in the construction process, and throwing and filling the stone materials with smaller grain size on the upper layer;

2. The construction method for installing the four-footed hollow blocks of the sea-facing breakwater according to claim 1, wherein in the step (3), the four-footed hollow blocks are installed from bottom to top by a crane and a steel wire rope, the four-footed hollow blocks are installed at the slope footer first, then the four-footed hollow blocks of the slope protection are installed from the first row upwards, and finally the four-footed hollow blocks at the top of the slope are installed after the pouring of the retaining wall is completed, and the specific installation method is as follows:

3. The offshore breakwater four-legged hollow block installation and construction method according to claim 2, wherein the hanger comprises a fixing plate, two sets of through holes are formed in the fixing plate, sleeves are arranged in the through holes, a clamping portion is arranged at one end of each sleeve, the clamping portion is of a circular structure, the diameter of the clamping portion is larger than that of the through holes, a supporting plate is arranged at one end, away from the clamping portion, of each sleeve, a rotating rod is arranged on each clamping portion, and three sets of hanging holes are formed in the fixing plate.

4. The offshore breakwater four-footed hollow block installation and construction method according to claim 3, wherein the concrete operations of lifting and placing the four-footed hollow block by the lifting appliance are as follows: aligning two sleeves of the lifting appliance to the middle hollow square part of the four-foot hollow square block, after the lifting appliance is placed in the four-foot hollow square block, rotating the sleeves after the sleeves penetrate through the lower surface of the four-foot hollow square block, enabling the supporting plate to clamp the lower surface of the four-foot hollow square block, starting lifting, rotating the sleeves after lifting is completed, taking out the sleeves, and sequentially operating.

5. The offshore breakwater four-legged hollow block installation and construction method according to claim 2, wherein a tonnage calculation method of a crane is selected as follows:

a＝arccos(S_max/L)

smax: a maximum horizontal distance;

primarily selecting a crane according to the weight of a lifted object and the maximum horizontal distance, measuring the arm length L of the crane, calculating the lifting angle a under the lifting condition of the maximum horizontal distance according to the calculation formula, and calculating the lifting angle a according to the a and the S_maxComparing the initially selected mechanical performance table of the crane, checking the load weight of the crane, and determining the load g on the lifting performance table of the crane<When the load weight Q is obtained, the crane must be selected again until Q is more than or equal to g.

6. The offshore breakwater four-legged hollow block installation and construction method according to claim 2, wherein the tonnage calculation method of the crane is selected as follows:

H_max＝H₁+H₂

H_l＝Lsina

a＝arcsin(H₁/L)

S＝Lcosa

in the formula: h_max: the maximum hoisting height;

l is the length of the suspension arm;

a, a is a hoisting angle;

s: and horizontally hoisting distance.

When the maximum hoisting height is limited, H_maxIs a known quantity. Primarily selecting a crane, wherein L is also a known quantity, obtaining a hoisting angle a and a horizontal distance S through the formula, comparing a mechanical performance table of the primarily selected crane according to a and S, checking the load weight g of the crane, and judging the load weight q when the load is lifted<And when the weight Q is loaded, the crane is reselected until Q is more than or equal to g.

7. The offshore breakwater four-legged hollow block installation and construction method according to claim 2, wherein the method for calculating the allowable tension of the steel wire rope is selected from the following methods:

[FG]＝AFG/K

in the formula: [ FG ] -allowable tension (KN) of the wire rope;

FG-the sum of wire breaking tensions (KN) of the wire ropes;

a-conversion factor;

k is the safety factor of the steel wire rope.