When drilling 5m deep, the verticality of the drill pipe should be checked and calibrated in time
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The size of steel casings is less than 5m in length and 180mm in width
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During the formal construction, it is necessary to check whether there are pipelines 3 meters above the ground, and communicate with the supervision unit in time to solve some problems
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When installing the reinforcement cage, the double ditch lifting method is generally adopted
.
At this time, the cohesive force of mud colloid can be used to make the sediment be taken out of the hole with the circulating flow of mud, so as to achieve the effect of cleaning the sediment
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The first step is after the hole is formed, and the second step is after the installation of reinforcement cage and conduit
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Standard operation ﹣ before drilling, the staff should clear the hole of the equipment, water pipes, electric pipelines, machines and tools of the drilling machine, and ensure that these equipment can operate normally
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In the construction process, the construction personnel should fully consider the process of bored pile, and strictly and scientifically manage and control the system and construction process, so as to ensure the construction quality of bored pile
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After the reinforcement is vertical, one lifting point can be removed and the first section of reinforcement can be placed behind the pile hole
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Hole cleaning construction: the hole cleaning process runs through the process of suspending the sediment at the bottom when the mud is flowing
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After reaching the standard, it can be accelerated
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After that, the construction personnel should use the retaining pile to restore, recheck the center pile of the pier according to the bridge axis control pile, use the total station to set out the center pile of each bored pile hole, and set the retaining pile points around
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When the underground water level is relatively high, the height of the Earth Island to be filled must be more than 1.5m higher than the top of the casing and the construction water, and the width of the top surface must be consistent with the width of the drilling machine equipment
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On the basis of ensuring that the mechanical properties of reinforcement materials meet the relevant technical requirements, the welding ends of main reinforcement shall be fixed with channel steel to ensure stability in a horizontal plane
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Balanced and symmetrical pouring: it depends on the eccentricity determined in the design
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During the construction of bored pile for bridge, it is not necessary to clean mud and hole in the whole manual process, but need to press casing link to observe and calibrate verticality at any time
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It is necessary to control the dosage of admixtures, mix the admixtures, inspect the mud after mixing, and make the mud according to the requirements applicable to the basic construction conditions
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Bored pile construction process and existing problems bored pile of beam bridge is usually the bored pile construction of building bridge
.
2
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The foundation of bridge construction is pile foundation, which is the “support” of the whole construction
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In view of this, in the actual work, we should prepare the site, build the workbench, install the drilling machine, insert the pressure casing, drill into the hole, fix the reinforcement cage, install the anti conduit, pour the concrete, pull the casing, and finally check the quality
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After a certain amount of mud is input into the orifice, the drilling can be carried out
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3.3 mud production problems: to make mud, we need to use high-quality bentonite, mud mixer, mud separator, mud pit, precipitator and other equipment to form mud production and circulation separation system
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In the process of construction, the position and direction of the bit should be checked in time
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Mastering the specific process is of great significance to the quality of the bridge
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3 reinforcement cage construction: first of all, the reinforcement cage should be made by long line method
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However, in deep water construction, reinforced concrete casing should be used
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3.2 the burying and preparation of casing should be done first, but there are two burying methods: filling and digging
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Methods and measures of bored pile construction technology ﹣ 1
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In the construction of bridge engineering, the mechanical drilling method is used to drill in the soil of the engineering base, and then the concrete is poured in the drilling area to form the bored pile
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The methods of hole cleaning include slurry replacement, slurry extraction, slag removal, mortar replacement, air compressor injection, etc
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in the drilling site shall be removed, and then the clay with a depth of 52cm shall be used for filling, which shall be leveled and compacted by bulldozers, and then bedded by sleepers
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At this time, the casing should be placed directly into the pit, and the center of the casing should be consistent with the center of the hole at the bottom of the pit, and finally compacted
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In accordance with the bridge engineering bored pile construction process operation
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Compared with the two, the advantages of bored pile construction are less noise, less vibration, larger diameter of pile, close bearing capacity between piles and wide range of foundation
.
4
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After the self-made mud meets the standard, it can be used to complete the drilling construction
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At the beginning of drilling, the drilling speed should be slow and uniform
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The safety technical measures of Bored Pile Construction: after the preparatory work of drilling, the relevant mechanical equipment and various preparatory work should be verified again to ensure the safety of operation
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In bad geological conditions, we should use mud to protect the wall, in order to better ensure the quality of the hole
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In order to facilitate future testing, the acoustic tube should be installed
.
The main reinforcement of reinforcement cage is usually connected by sleeve
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Secondly, the production of casing
.
Generally, when the main span L ≤ 80m, the quantity of asymmetric pouring concrete shall not exceed 5M3
.
To set the lifting point at the connection point of the main reinforcement and stirrup, it is best to lift successfully at one time
.
2
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In the whole process, there are not only bored pile construction, but also cast-in-place pile construction and bored pile construction
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3 problems to be solved in bored pile construction bored pile reinforcement can enhance its bending bearing capacity, inhibit the development of cracks, reduce structural deformation and improve the strength bearing capacity of bridge materials
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First of all, the staff should start the mud pump and let it idle for a while
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For the summary of the key points of bored pile construction technology in bridge engineering, the main contents of construction method are as follows
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The method of digging and burying is suitable for when the underground water level is more than 1m above the ground, it is necessary to dig a round pit (the length of the round hole should be 40cm larger than the casing itself, and the diameter should be about 45 cm larger than itself), and then fill 40cm clay at the bottom of the pit
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The length of each section of casing should be about 2m, the thickness should be about 9cm, and the pipe wall must be flat and uniform
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Generally speaking, there are two steps in the hole cleaning process
.
Finally, the reinforcement cage is lengthened on site with straight thread sleeve
.
At present, the main beam reinforcement technology and external prestressed reinforcement technology are widely used, among which the bored pile construction reinforcement technology is the most widely used
.
It is necessary to formulate corresponding safety technical measures for the installation and positioning of the bridge hanging basket, the stress and back anchor of the hanging basket, the balanced and symmetrical pouring, the movement of the hanging basket, the removal of the hanging basket, etc
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The process of bored pile is operated in strict accordance with the process of bridge bored pile, which plays a very important role in the stiffness and bearing capacity of bridge structure
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Because the bored pile construction technology has concealment in the whole construction process, the construction personnel should strictly control the quality of the whole project according to this characteristic
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During operation, long-term stress monitoring system and health inspection system should be set up in key parts.
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For example, according to the design of the main tower of the bridge is hollow or solid tower operation, the general height below 80m can use turnover formwork construction, and turnover formwork construction is the main source of danger is the dismantling and lifting of the formwork, as well as the safety fence setting of construction workers
.
During the construction of bridge tower, the main tower with different section and height has different construction methods, and different construction methods have different risks
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Only in this way can the bridge engineering be more solid and firm
.
Bridge engineering construction belongs to high-altitude construction work, such as bridge main tower construction, stay cable construction, cantilever pouring construction and so on is more dangerous
.
At present, there are more steel casings
.
3.1 site leveling and positioning: before the construction, the debris, hard rock, silt, etc
.
In the process of construction, it is necessary to constantly clean up the sediment, waste mud and dirt in the sedimentation tank, and pay attention to environmental protection when cleaning these
.
Before construction, a complete construction organization design must be prepared and approved by the supervision engineer
.
