Prefabricating process for ultrahigh and oversized asymmetric barrel type foundation

Abstract

The invention provides an ultra-high and ultra-large asymmetric barrel type foundation prefabrication process which comprises the steps that a barrel type foundation is at least divided into two parts, the height of the upper half part is smaller than that of the lower half part, then prefabrication is conducted according to the sequence from bottom to top, and each part is constructed in a layered pouring mode; the layered pouring is divided into at least three layers, and each layer is prefabricated according to the sequence of steel bar binding, formwork installation, concrete pouring and formwork removal; in the layered pouring, each layer is divided into a plurality of compartments, an inner mold in each compartment is of an integral structure, and a demolding state or a demolding state is formed among the compartments by hoisting and adjusting screw rods; in the formwork installation process, a sealing process is carried out on the outer formwork, and the sealing process comprises the step that trapezoidal chamfers and rubber sealing strips are formed on the top and the lower portion of the outer formwork through rubber respectively.

Description

Technical Field

[0001] The invention relates to the technical field of prefabrication of bucket foundations, and in particular to a prefabrication process for an ultra-high and ultra-large asymmetric bucket foundation. Background Art

[0002] In the existing technology, bucket foundations are all symmetrical structures, with relatively simple prefabrication processes, and the large formwork and pouring processes involved are symmetrical in the axisymmetric direction. However, this project uses an asymmetrical bucket foundation, and the large formwork needs to be spliced ​​and combined, which requires a higher level of control over the appearance of the concrete. The pouring method and pouring volume must be calculated in detail, requiring a higher level of sophistication in the process. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a prefabrication scheme for a bucket foundation with an asymmetric structure, which not only enables the prefabrication of a bucket foundation with a complex structure but also improves the overall quality.

[0004] In order to solve the above technical problems, the technical solutions provided by the present invention are as follows:

[0005] A super-high and super-large asymmetric bucket foundation prefabrication process, wherein the bucket foundation is divided into at least two parts to form an upper bucket body and a lower bucket foundation, and the height of the upper bucket body is less than the height of the bucket foundation, and then prefabrication is performed in order from bottom to top, and each part is constructed by layered pouring;

[0006] The layered pouring is divided into at least three layers, and each layer is prefabricated in the order of steel bar binding, formwork installation, concrete pouring and formwork removal;

[0007] In the layered casting, each layer is divided into a number of compartments, and the inner mold in each compartment adopts an integral structure. The compartments are connected by lifting and adjusting screws to form a demoulding state or a demoulding state;

[0008] The template installation also includes a sealing process at the outer template, and the sealing process includes using rubber to form trapezoidal chamfers and rubber sealing strips at the top and bottom of the outer template respectively.

[0009] Furthermore, the template installation includes bottom template installation, and the bottom template installation specifically forms a construction area with a fixed bottom template, and the movable bottom template is transported to a set position in the construction area by a module vehicle.

[0010] Furthermore, the fixed bottom formwork includes a concrete foundation and a steel box beam, and the movable bottom formwork includes a steel box beam located on a jack and assembled through a steel cushion beam.

[0011] Furthermore, it also includes a slurry leakage structure located outside the bottom mold, and the slurry leakage structure forms a semi-enclosed cavity extending obliquely from the outside to both sides of the end of the bottom mold.

[0012] Furthermore, the template installation also includes the installation of side templates, specifically using arc segment templates and straight segment templates to splice together to form a lower barrel structure or an upper foundation structure.

[0013] Furthermore, tie rods are provided on both the upper and lower sides of the side formwork, and the tie rods are pre-buried in the existing building or the constructed layer so that the tie rods form a pair of tie rods. ---27 pages

[0014] Furthermore, the inner molds of the several compartments in the template installation are installed in the order of the middle first, then the surroundings, and finally the four corners, and after each inner mold is hoisted and installed, the inner mold is spread out.

[0015] Furthermore, the length of the barrel foundation is less than or equal to 36-40m, and the length of the upper barrel body is less than the length of the lower foundation.

[0016] Furthermore, the length of the lower foundation is 10-14m, and the lower structure is divided into at least 12 compartments.

[0017] Furthermore, the upper barrel body is a rectangular structure with a width of 14-13.6m, and the rectangular structure is divided into at least compartments.

[0018] The present invention has the following beneficial effects:

[0019] The prefabrication process of the present invention satisfies the prefabrication construction of a large asymmetric structure with a length of 40 m, so that it can be applied to the construction of ship docks and the like to improve the overall construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of a super-high and super-large asymmetric barrel foundation prefabrication process provided by the present invention;

[0021] Figure 2 A schematic structural diagram of the super-high and super-large asymmetric barrel foundation provided by the present invention; 100, an upper barrel body; 200, a lower barrel body. DETAILED DESCRIPTION

[0022] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0023] See attached Figure 1As shown, a super-high and super-large asymmetric bucket foundation prefabrication process in this embodiment is characterized in that the bucket foundation is divided into at least two parts to form an upper bucket body 100 and a lower bucket foundation, and the height of the upper bucket body 100 is less than the height of the bucket foundation, and then prefabrication is carried out in order from bottom to top, and each part is constructed by layered pouring;

[0024] The layered pouring is divided into at least three layers, and each layer is prefabricated in the order of steel bar binding, formwork installation, concrete pouring and formwork removal;

[0025] In the layered casting, each layer is divided into a number of compartments, and the inner mold in each compartment adopts an integral structure. The compartments are connected by lifting and adjusting screws to form a demoulding state or a demoulding state;

[0026] The template installation also includes a sealing process at the outer template, and the sealing process includes using rubber to form trapezoidal chamfers and rubber sealing strips at the top and bottom of the outer template respectively.

[0027] Specifically, the template installation includes bottom template installation, and the bottom template installation specifically forms a construction area with a fixed bottom template, and the movable bottom template is transported to a set position in the construction area by a module vehicle.

[0028] Furthermore, the fixed bottom formwork includes a concrete foundation and a steel box beam, and the movable bottom formwork includes a steel box beam located on a jack and assembled through a steel cushion beam.

[0029] In this embodiment, a slurry leakage structure is also included on the outside of the bottom mold, and the slurry leakage structure forms a semi-enclosed cavity extending obliquely from the outside to both sides of the end of the bottom mold.

[0030] In this embodiment, the template installation also includes the installation of side templates, specifically using arc segment templates and straight segment templates to splice together to form a lower barrel structure or an upper foundation structure.

[0031] In this embodiment, tie rods are provided on the upper and lower sides of the side formwork, and the tie rods are pre-buried in the existing building or the constructed layer so that the tie rods form a pair of tie rods.

[0032] In this embodiment, the order of installing the inner molds of the several compartments in the template installation is to install the middle first, then the surroundings, and finally the four corners, and after each inner mold is hoisted and installed, the inner mold is spread out.

[0033] In this embodiment, the length of the barrel foundation is less than or equal to 36-40 m, and the length of the upper barrel body 100 is less than the length of the lower foundation.

[0034] In this embodiment, the length of the lower foundation is 10-14 m, and the lower structure is divided into at least 12 compartments.

[0035] In this embodiment, the upper barrel body 100 is a rectangular structure with a width of 14-13.6 m, and the rectangular structure is divided into at least compartments.

[0036] In this embodiment, the ultra-high and ultra-large asymmetric barrel foundation is specifically formed, including an upper barrel body 100 and a lower barrel body 200, and the barrel body with an upper rectangular structure is set away from the center line of the lower cylindrical barrel body structure, so that it is not only asymmetric from top to bottom, but also the center lines of the upper and lower structures are deviated, forming an asymmetric structure.

[0037] In the prior art, the maximum height of a general hydraulic structure is 20m, the size is 20*10m, and the mass is 1000T. In this embodiment, the barrel foundation has a size of 40*20m, a height of 40m, and a weight of more than 6000T.

[0038] The technical solution of the present invention is used in a certain partially confidential project, and the relevant introduction is as follows:

[0039] 1. Project introduction

[0040] This project mainly includes the container terminal project in the operation area and the supporting workboat terminal project. The workboat terminal adopts a barrel-type foundation structure, and the components are produced in a prefabrication plant.

[0041] In this embodiment, the workboat dock has a total of 30 barrel-type foundation structures, which are composed of three sizes. The statistical table is shown in Table 1:

[0042] Table 1 Barrel type basic dimensions

[0043]

[0044] As can be seen from Table 1, the barrel foundation structure consists of a lower foundation barrel and an upper barrel. The long axis of the lower foundation barrel is 40 / 36.6m, the short axis is 20m, the height is 10-14m, the outer barrel wall thickness is 400mm, the lower barrel top cover is 300mm thick, and the cast-in-place surface layer is 200mm. The barrel is divided into 15 / 12 compartments by partitions, and the partition thickness is 300mm. There are 2 partitions arranged along the long axis of the barrel and 4 / 3 partitions arranged along the short axis.

[0045] The upper barrel is rectangular, 20m long, 14m / 13.6m wide, 9-12.5m high, with an outer barrel wall thickness of 400mm. The barrel is divided into 6 compartments by 3 partitions, and the partitions are 300mm thick.

[0046] Second, the prefabrication is introduced by taking the barrel as an example.

[0047] In this embodiment, taking the highest barrel-type foundation structure of lower barrel 14m + upper barrel 12.5m as an example, the barrel-type foundation structure is manufactured in layers on a production pedestal, and concrete is poured 7 times from bottom to top, including 3 times for the lower barrel body, 1 time for the top cover plate and 3 times for the upper barrel body.

[0048] The lower barrel body is divided into 3 layers. The steel bars are tied on the pedestal in sequence and then cast in the formwork. The top plate of the lower barrel adopts the composite plate construction process. After the prefabricated plate is installed, the cast-in-place surface layer is carried out. The upper barrel body steel bars are hoisted onto the lower barrel body after the overall tying in the special area, and cast in 3 layers.

[0049] The lower barrel body is layered as follows: the first layer is 5.3m, the second layer is 4m, and the third layer is 4.2m. It is constructed to the bottom of the cover plate. After the prefabricated cover plate is installed, a 0.5m cast-in-place cover plate layer is poured. The upper barrel body is poured in 3 layers, the first layer is 2m, the second layer is 5.25m, and the third layer is 5.25m.

[0050] In this embodiment, the prefabrication process of the barrel foundation formed by the lower barrel body is as follows:

[0051] The lower barrel is prefabricated in three layers. The first, second and third layers of steel bars are tied on the pedestal and then cast in a vertical formwork.

[0052] 1. Bottom mold process.

[0053] The overall length of the bottom formwork is 40 meters, the width is 20 meters, and the height is 0.39 meters. It adopts the form of "fixed bottom formwork + movable bottom formwork", in which the module vehicle walking area (16 meters wide) adopts 3 movable bottom formworks, and the movable bottom formwork is a structure of 0.39m high steel box beam + 0.6 steel cushion beam + jack. The area outside the module vehicle walking adopts the fixed bottom formwork, which includes a 0.9m wide and 1.21m high concrete foundation and a 0.39m high steel box beam, with a total height of 1.6m.

[0054] In this embodiment, the bottom formwork structure has a construction area formed by fixed bottom forms on both sides, and then the movable bottom forms are distributed at both ends and the middle position, so that relevant movable construction movements can be carried out in the construction area. Then, prefabricated foundation barrels are respectively set on the fixed bottom formwork and the movable bottom formwork, so that the fixed bottom formwork and the movable bottom formwork form a support. For example, for the fixed bottom formwork, a steel box beam is set on the concrete foundation, and then a prefabricated foundation barrel is set on the steel box beam. For the movable bottom formwork, the steel box beam is supported by a jack, and then a prefabricated foundation barrel is set on the steel box beam.

[0055] In this embodiment, when the bottom formwork is erected, the floor is first cleaned, the position of the bucket foundation is measured and laid out, and the steel bottom formwork is installed. The outer dimensions of the bucket foundation are mainly controlled by the bottom formwork. The processing and installation of the bottom formwork require precision. The height difference of the bottom formwork is less than 5mm. The steel bottom formwork after installation requires good integrity. Dovetail rubber strips are used on the sides to prevent concrete leakage. Specifically, the dovetail rubber strip forms a semi-enclosed cavity that extends obliquely from the outside to both sides of the bottom formwork end. That is, from the outside to the inside, the openings are concentrated inward, and the openings of the two leakage structures are close.

[0056] 2. Side mold process.

[0057] In this embodiment, the outer side template of the lower barrel is supported by three layers, and the layer height is 5.3m+4m+4.2m.

[0058] The outer formwork consists of 8 pieces of outer formwork, including 4 pieces of straight segments and 4 pieces of 1 / 4 arc segments. The weight of a single piece of formwork is about 11-18t. The formwork surface is formed by a combination of 8mm thick stainless steel composite panels and [12# channel steel transverse ribs. [10# channel steel is welded into a truss structure as a vertical back rib. Two tie rods are set up above and below the formwork, and no through-wall tie rods are set to ensure the air tightness of the barrel. When pouring the second and third sections of the lower barrel, the upper outer formwork is placed on the truncated cone nut pre-buried on the top of the lower barrel, and also serves as a tie rod at the bottom of the upper formwork.

[0059] The template assembly uses the shipping channel between the two prefabrication lines as the site, and the assembled forming templates are circulated between the pedestals or temporarily stored in the area between the two pedestals.

[0060] The template is assembled with an 80t truck crane, and after assembly is completed, it is hoisted to the prefabricated pedestal line and installed with a gantry crane. The template weighs about 30t at its heaviest, is about 9.25m long, has a central hoisting point of about 6m, and a hoisting height of 10m. Check the 80t truck crane performance table to see if it meets the requirements.

[0061] In this embodiment, in order to ensure good appearance quality, a rubber trapezoidal chamfer is set on the top of the outer template, and a rubber sealing strip is installed at the bottom to ensure that the joint does not leak mortar and prevent sand from returning.

[0062] In this embodiment, during the layered casting, each layer is divided into a number of compartments, and the inner mold in each compartment adopts an integral structure. The compartments are connected by lifting and adjusting screws to form a demoulding state or a demoulding state; the specific description is as follows:

[0063] In this embodiment, the inner mold of each compartment adopts an integral structure, and the template can be retracted and extended into a "demolding state" and a "molding state" by using an adjusting screw. When installing the template, the integral inner mold in the "demolding state" is first hoisted into the compartment by a gantry crane, and then the template is assembled into a "molding state" by using an adjusting screw.

[0064] Each layer of each lower barrel body is composed of 15 inner molds. The template surface is formed by a combination of 8mm thick steel plates and transverse ribs of [12# channel steel. [10# channel steel is welded into a truss structure as a vertical support structure.

[0065] After the reinforcement is tied, the inner formwork is erected first, and then the outer formwork is installed. The side formwork of each compartment is hoisted as a whole; the formwork is adjusted and reinforced as a whole, and concrete is poured after passing the acceptance. In order to ensure that the geometric dimensions of the concrete meet the requirements of the standard, the verticality, elevation and plane dimensions are controlled layer by layer when the formwork is erected, and the bolts are tightened.

[0066] The inner formwork is installed from the middle to the surroundings. The binding platform is hoisted out first according to the numbering sequence, and then the inner formwork is hoisted in and the formwork is opened in time to ensure the stability of the steel skeleton. Finally, the steel binding platforms at the four corners (12#, 13#, 14#, 15#) are hoisted out, the inner formwork at the four corners is hoisted in, and the formwork is opened in time.

[0067] The installation sequence of the outer mold is based on the installation sequence of the inner mold. When removing the template, first remove the inner mold, then remove the outer mold, the order is the same as when installing. That is, first construct the lower half of the barrel foundation, and then construct the upper barrel body.

[0068] 3. Steel bar technology.

[0069] In this embodiment, the steel bars are processed and manufactured in a steel bar processing plant of an offshore engineering base, and after being formed, they are transported to the pedestal by a flatbed truck for lifting and installation.

[0070] According to the characteristics of the process, the steel bars are constructed in a modular manner, and a tying platform is set up in the lower barrel for layered tying. After the bottom formwork is installed and passed the acceptance, the steel bar tying platform is hoisted into the bottom formwork compartment, and the operator ties the steel bars on the platform according to the layered pouring height.

[0071] The assembly of the steel bar binding frame utilizes the shipping channel between the two prefabrication lines as the site. The assembled steel bar binding frame circulates between the pedestals or is temporarily stored in the area between the two pedestals.

[0072] The steel bar binding frame is assembled with an 80t truck crane. After assembly, it is hoisted to the prefabricated pedestal line and then hoisted into the compartment by a gantry crane. The maximum weight of the steel bar binding frame is about 15t. Check the performance table of the 80t truck crane to meet the requirements.

[0073] For steel bar binding, first install and fix the steel bar frame with hanging wire, arrange it with a spacing of 1.5 meters, then pass the horizontal reinforcement, and finally increase the density of vertical reinforcement. The steel bar joints are made of binding joints.

[0074] The steel pads are arranged in a diamond shape with a spacing of 1m. To prevent the concrete pads from shifting or tipping over during the formwork installation process, diamond pads are used at the bottom and 3cm thick round pads are used for the side walls.

[0075] 4. Concrete engineering.

[0076] (1) Concrete configuration.

[0077] 1) Design requirements.

[0078] The concrete structures of this project all use high-durability concrete. High-durability concrete should have high resistance to chloride ion penetration, high dimensional stability and good workability; it should comply with the relevant provisions of the "Water Transport Engineering Concrete Quality Control Standard", "Water Transport Engineering Concrete Construction Specification" and "Water Transport Engineering Structure Durability Design Standard".

[0079] The relevant technical requirements for adding harbor concrete anti-corrosion enhancer (CPA) to the barrel cover plate and the concrete structure above the barrel foundation structure are as follows:

[0080] a. Specific surface area ≥ 300m 2 / kg.

[0081] b. Setting time: initial setting time ≥ 45 minutes, final setting time ≤ 10 hours.

[0082] c. Standard test limit expansion rate (10% internal doping): 7 days in water> 0.025%; 21 days in air> -0.015%.

[0083] d. Compressive strength ratio: According to the strength test method of GB / T 50081, the 7-day strength ratio shall be ≥90%; the 28-day strength ratio shall be ≥100%.

[0084] e. Chloride ion permeability resistance (C) <1000 coulomb.

[0085] f. The dosage of anti-corrosion enhancer is 40kg / m 3 .

[0086] 2) Laboratory mix ratio

[0087] According to the design requirements, after raw material comparison and mix trial, the mix ratio is determined as shown in Table 2 below. The lower barrel structure adopts the 1# mix ratio, and the lower barrel cover plate and the above concrete structure adopt the 2# mix ratio.

[0088] Table 2

[0089]

[0090] (2) Concrete pouring

[0091] Concrete is centrally supplied by mixing stations, transported horizontally by tank trucks, and pumped into molds by pump trucks.

[0092] The production capacity of two 4-cubic-meter mixers is 160 cubic meters per hour, the pouring speed is 70 cubic meters per hour, the first layer with the largest volume is about 367 cubic meters, and the planned pouring time is 5-6 hours.

[0093] During pouring, two pump trucks pour symmetrically, placing materials in layers from the outer circle to the partition wall. The first layer is controlled at a height of 80cm, and the remaining layers are placed at a height of no more than 50cm.

[0094] The concrete pump truck is configured with 2 units of 47m+53m each. The barrel foundation structure is 25.5m high, 40m wide, and 20m from one side to the center. The length of the pump truck can meet the construction requirements.

[0095] Since the lower barrel is divided into 15 compartments, in order to ensure that the vibration is in place, the vibrating personnel need to carry out construction work in the compartments, with 2 to 3 people and 2 vibrating rods in each compartment, and the vibration length each time is 12-13 meters.

[0096] When vibrating concrete, the vibration time of each vibration point is until the concrete is compacted until the surface shows floating slurry and no longer sinks; when vibrating concrete, first outside and then inside, the vibration interval is 300mm, and the continuous vibration time of each vibration point is 15-20s, until the concrete surface shows cement slurry and no longer sinks. The vibrating rod is inserted vertically into the concrete, and it is inserted quickly and pulled out slowly, and pumped up and down to ensure that the upper and lower layers of concrete are combined into a whole. The vibrating rod is inserted into the lower layer of concrete for 5-10cm; to ensure that the vibrator is inserted into the concrete to an appropriate length, a marking line is tied to the vibrating rod hose, with a spacing of 50cm. The vibration time of each vibration point is 2 seconds. When each layer is ashed to the top, a secondary vibration is carried out to remove the floating slurry and ensure that the top of each layer is not loose. And use 5cm*5cm*50cm long wooden strips to press the groove to ensure the connection of the upper and lower layers of concrete.

[0097] (3) Concrete curing

[0098] After the surface concrete is poured, it should be covered with geotextiles or other materials with good water retention in time to prevent water loss due to wind drying and sun exposure. Moisturizing maintenance should be started immediately after hardening.

[0099] 12 hours before removing the formwork, loosen the fastening nuts of the side formwork to allow the curing water to seep down along the surface where the formwork and concrete are separated to cure the concrete side. When the temperature is low, pay attention to covering with insulation materials to keep the concrete moist and warm. During the entire curing period, especially in the initial stage of curing from final setting to removing the formwork, ensure that the concrete is in a temperature and humidity environment that is conducive to hardening and strength growth. Curing at room temperature for at least 14 days.

[0100] The inner side of the barrel is maintained with curing liquid, and the outer side is maintained with water spraying.

[0101] 5. Top plate construction

[0102] The cover plate prefabrication is completed in the cover plate prefabrication area. The cover plate prefabrication and installation process specifically includes bottom formwork laying, steel bar binding, side formwork installation, concrete pouring, formwork removal and maintenance, and installation.

[0103] After the cover is prefabricated, it is transported to the storage site by flatbed truck for storage. The cover is stored in 3 layers, and each layer is separated by 15*15cm wooden blocks. During installation, it is transported to the lower barrel where the cover needs to be installed by flatbed truck, and installed by gantry crane.

[0104] After the cover plate is installed, the next step is to cast the panel in situ. The process of casting the panel in situ includes steel bar binding, side form installation, concrete pouring, plastering, and formwork removal and maintenance.

[0105] Before pouring concrete, the steel bars, edge angles, embedded iron parts, and formwork supports should be checked and accepted, cleaned, and moistened with water.

[0106] After leveling, take out the horizontal pipe, add concrete immediately, fill and level the footprints and steel pipe marks, and vibrate to maintain the uniformity of the concrete; use a 2m long scraper to level to control the water dispersion slope. Use a long scraper to scrape the surface slurry and segregated water out of the surface layer to increase the density and tensile strength of the concrete, and reduce the water from penetrating into the concrete and then freeing and escaping to form cracks.

[0107] The finishing should be carried out according to the requirements of the specifications. Generally, the suspended finishing is adopted three times. After leveling, beating the slurry and rough leveling, first use a wooden scraper to smooth the elevation to make the concrete initially level. After the concrete has a certain strength, smooth it again. Finally, wait for the moisture precipitated on the surface of the concrete to evaporate before pressing it for the third time with an iron plate.

[0108] After the cast-in-place surface layer is completed, timely maintenance is carried out. For maintenance, plastic film is covered on the surface concrete, and then a layer of damp geotextile is covered on it, so that the concrete structure can be maintained under the condition of heat preservation and moisture retention, thereby improving the tensile strength of the concrete and reducing the temperature difference between the inside and the outside.

[0109] Third, prefabricate the upper barrel body.

[0110] In this embodiment, the prefabrication process of the upper barrel body formed by the upper barrel body is as follows:

[0111] 1. Steel bar technology

[0112] The first 2m high layer of the upper barrel body steel bars is tied in situ on the pedestal, and the next two layers are tied and hoisted as a whole according to the layered height. The steel cage is tied on a separate binding platform outside the field, and after completion, it is hoisted as a whole using a special hanger.

[0113] Before hoisting, the steel bars must be fixed and supported. The hanger and the steel bars must be securely fixed to prevent the steel bars from falling off during the hoisting process. A guy rope should be set for the hoisted objects to prevent the steel cage from shaking significantly.

[0114] 2. Side mold process

[0115] The outer formwork of the upper barrel is supported by three layers, with each layer having a height of 2m+5.25m+5.25m. The overall formwork is similar to the lower barrel formwork.

[0116] When installing the upper barrel formwork, install the inner formwork first. After the formwork is reinforced, install the outer formwork. Use upper and lower layers of tie rods for reinforcement. Use U-shaped bolts to pull the outer side of the bottom toe plate back on the embedded steel bars on the top of the lower barrel body. After the first layer of formwork is erected, start pouring concrete. After the concrete pouring is completed, erect the second layer of formwork.

[0117] The inner mold of a single compartment of the upper barrel is mainly divided into a hoisting frame, a panel and a truss. The panel and the truss are supported by the hoisting frame. When the inner mold is installed, adjustment and reinforcement measures should be taken immediately after a template is put into the mold. The panel and the truss should be supported in place using the adjusting screw, and slurry stopping and reinforcement measures should be taken.

[0118] 3. Concrete Engineering

[0119] During pouring, two pump trucks pour symmetrically, placing materials in layers from the outer circle to the partition wall. The first layer is controlled at a height of 80cm, and the remaining layers are placed at a height of no more than 50cm.

[0120] Since the upper barrel is divided into 6 compartments, in order to ensure that the vibration is in place, the vibrating personnel need to carry out construction work in the compartments.

[0121] Part 4: Shipment of barrel foundation.

[0122] After the barrel foundation is prefabricated, its shipment is mainly completed by module vehicles. The module vehicles enter each prefabricated pedestal, lift up the barrel foundation and directly move it onto a semi-submersible barge.

[0123] In this embodiment, it also includes on-site transportation, and the process is as follows:

[0124] 1. Module car layout plan

[0125] 2.43m modular vehicles are used for transportation, with a total of 176 axles and 5 power module units (PPUs). Five single vehicle groups are used for transportation, and all vehicle groups are divided into four large groups. The 5 vehicle groups are supported by four points as a whole, and the lifting pressure of the vehicle groups in the same group is equal.

[0126] The prefabrication process of the present invention has the following characteristics:

[0127] 1. Formwork Engineering

[0128] (1) The barrel foundation structure is a thin-walled, large-volume concrete structure, most of which is operated at high altitude. The formwork uses a large steel structure composite formwork. Before the formwork is made, it is required to verify the strength, rigidity, and integrity of the formwork to ensure that the rigidity, deflection, and safety of the formwork meet the requirements of the specification.

[0129] (2) When erecting the bottom formwork, first clean the floor, lay out and measure the position of the bucket foundation, and install the steel bottom formwork. The outer dimensions of the bucket foundation are mainly controlled by the bottom formwork. The processing and installation of the bottom formwork require precision. The height difference of the bottom formwork is less than 5mm. After installation, the steel bottom formwork requires good integrity. Use triangular rubber strips on the sides to prevent concrete leakage.

[0130] (3) Side formwork support: After the reinforcement is tied, the inner formwork is supported first. The side formwork of each cabin is assembled using the assembly and disassembly formwork frame. The side formwork of each cabin is hoisted as a whole; then the outer formwork is supported. The formwork is adjusted and reinforced as a whole, and concrete is poured after acceptance. In order to ensure that the geometric dimensions meet the requirements of the specifications and standards, the verticality, elevation and plane dimensions of the supported formwork are controlled layer by layer, and the bolts are tightened.

[0131] (4) Except for the embedded steel pipes opened for negative pressure sinking, it is strictly prohibited to open holes in the outer wall, partition and top plate of the foundation barrel.

[0132] (5) Before erecting the formwork, clean the surface and evenly apply the release agent. The release agent should be produced by a professional manufacturer with many years of experience in use. It is suitable for steel formwork demoulding and has a beautiful appearance of concrete after demoulding.

[0133] (6) When the concrete strength reaches the design requirements, the formwork is removed and the formwork is required to be cleaned and oiled for maintenance. It is required to be cleaned again and the release agent is applied before it is used again.

[0134] (7) After the reinforcement is tied, the position of the embedded steel plate and bolt holes must be carefully measured to determine the position of the embedded steel plate. After the steel plate is positioned, it must be carefully re-measured to ensure that it is consistent with the design.

[0135] After the embedded steel plate is positioned, it is welded together with the steel frame to ensure that no displacement occurs during concrete pouring.

[0136] 2. Steel bar engineering

[0137] (1) Before processing the steel bars, they must be straightened, rusted, and degreased.

[0138] (2) When tying steel bars, tie them from inside to outside and from longitudinal to transverse.

[0139] (3) The steel bar binding requires one-time forming. Butt welding joints are used when making steel bars. The steel bar joints tied on site are lap welded. Lap welding is used along the circumference of the barrel foundation and the connection between the upper barrel and the lower barrel. Butt welding joints are used as much as possible. Pay attention to staggering lap welds to ensure that the joints in the same section are less than half of the total number of steel bars in the section. When prefabricating the cover plate, pay attention to reserving the toe plate steel bars and lap steel bars of the upper barrel.

[0140] (4) The arrangement, binding size, and specifications of the steel bars must meet the design requirements. The steel bars must have sufficient rigidity after forming to avoid bending and deformation of the steel bar skeleton after forming. The binding wires must be pressed inwards uniformly.

[0141] (5) When tying the steel bars, be careful to avoid the cone nuts.

[0142] (6) The steel bar protective layer pads are made by machines, and their strength and chloride ion penetration resistance are not lower than the design requirements of the components themselves. The thickness deviation of the pads meets the specifications and standards. The pads are firmly supported, with no less than 4 per square meter, to ensure that the steel bars do not move or deform during the concrete pouring process.

[0143] (7) Embedded parts must be inspected upon arrival, including material, thickness, hole position, plane dimensions, etc. The installation of embedded parts must ensure accuracy, and the positioning plate must be welded to the steel bars after installation to ensure a firm connection. Acceptance must be carried out before sealing the mold.

[0144] 3. Concrete Engineering

[0145] (1) The raw materials and quality of concrete must comply with the current industry standard "Concrete Construction Specifications for Water Transport Engineering (JTS202-2011)" and the relevant national standards.

[0146] (2) The concrete mix design should comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering" (JTS202-2011) and other relevant provisions.

[0147] (3) The total chloride ion content and alkali content in concrete should comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering" (JTS202-2011).

[0148] (4) The strength of concrete must meet the design requirements and should comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering".

[0149] (5) For concrete with requirements for frost resistance and water-resistance, its frost resistance and water-resistance should comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering" and other relevant provisions.

[0150] (6) The chloride ion permeability resistance of concrete should meet the design requirements and comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering".

[0151] (7) The location and treatment of construction joints should meet the design requirements and comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering".

[0152] (8) Concrete maintenance should comply with the relevant provisions of the current industry standard "Concrete Construction Specifications for Water Transport Engineering" and other relevant regulations.

[0153] (9) Consider adding rust inhibitors and other factors to concrete and appropriately extend the mixing time as required by the specifications to ensure that the concrete is mixed evenly.

[0154] (10) When vibrating concrete, vibrate outside first and then inside, with a vibration interval of 300mm. The continuous vibration time at each vibration point is 15 to 20 seconds, and the vibrating rod is inserted vertically into the concrete, and inserted quickly and pulled out slowly, pumping up and down to ensure that the upper and lower layers of concrete are combined into a whole. The vibrating rod should be inserted into the lower layer of concrete for no less than 5cm. To avoid excessive floating slurry on the top, reduce water in layers.

[0155] (11) In order to control the vibration of each layer of concrete, mark the vibrator hose with tape or other means, and control the insertion depth of the vibrator according to the mark.

[0156] (12) As the air tightness of the barrel is extremely important, it is the focus of control:

[0157] a. Control the slump of concrete so that it is not too large. After pouring, drain the floating slurry on the top, roughen the construction joints, and remove the cement film, loose stones and weak concrete layer on the hardened concrete surface.

[0158] b. The upper layer of concrete can only be poured after the compressive strength of the lower layer of concrete reaches 1.2MPa.

[0159] c. Before pouring new concrete, first wet the old concrete surface with water, and do not allow water to accumulate in low-lying areas. Then lay a layer of cement mortar with a thickness of 10 to 30 mm. The water-cement ratio of the cement mortar is less than that of the concrete.

[0160] d. Considering that the barrel is installed by air flotation and sinking under negative pressure, the air tightness requirements for the base barrel are relatively high. The two construction joints of the base barrel are required to be grooved, roughened and installed with water stop strips.

[0161] e. After the construction is completed, an airtightness check should be carried out to check whether there are cracks on the barrel cover, exterior wall and partition wall, whether there are honeycombs or damage on the partition wall, whether the concrete in the joints is dense, etc.

[0162] 4. Bucket-type foundation structure shipment

[0163] (1) The operator should concentrate on the correct operation. The formal operation can only be carried out after the trial lifting operation is confirmed to be normal. It is strictly forbidden to make or answer calls while driving. The operation of various parts of the machine and the instrument indication values ​​must be monitored at any time. If any abnormality is found, the machine should be stopped immediately for maintenance.

[0164] (2) Operators must strictly abide by relevant traffic regulations and prohibit speeding and overloading; the fully loaded driving speed should be controlled within 0.3 to 0.5 km / h.

[0165] (3) During loading operations, the operator and supervisor should stand 3 to 5 meters in front of or behind the module vehicle.

[0166] (4) If a vehicle breaks down during transportation, the goods need to be supported during the repair process, and the suspended parts should be padded; the support valves of the four supporting points of the module vehicle should be closed, and the oil stains on the ground should be cleaned up in time after the repair is completed.

[0167] (5) If any of the following situations occur during construction, work should be stopped immediately and construction can only be continued when the safety conditions for the operation are met.

[0168] The barrel foundation in this embodiment is not the integral cylindrical structure in the prior art, but a rectangular structure, and the lower layer is a normal barrel-type, forming an asymmetric structure. Moreover, its overall specifications are relatively large, forming an ultra-high and ultra-large asymmetric structure. Therefore, the prior art is difficult to meet the prefabrication of this special structure. The scheme in the present invention realizes the prefabrication process of the asymmetric structure and improves the overall construction efficiency.

[0169] In this embodiment, the maximum barrel structure length is 40m, width is 20m, the lower barrel height is 14m, the upper barrel height is 12.5m, and the weight is 5492 tons, forming an ultra-large asymmetric structure. In this embodiment, the movable setting of the bottom mold, etc., and then the entire space layout, etc., meet the barrel foundation transportation requirements and the requirements that the module vehicle can enter and exit smoothly; in this embodiment, the assembly sequence of the side mold and the inner mold is adjusted to make the assembly quality meet the corresponding requirements; and at the joints of the prefabricated sections, sealing is used to meet the water-stopping requirements.

[0170] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0171] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A super-high and super-large asymmetric barrel foundation prefabrication process, characterized in that: The bucket foundation is divided into at least two parts to form an upper bucket body and a lower bucket foundation, and the height of the upper bucket body is less than the height of the bucket foundation, and then prefabrication is carried out in order from bottom to top, and each part is constructed by layered pouring; The layered pouring is divided into at least three layers, and each layer is prefabricated in the order of steel bar binding, formwork installation, concrete pouring and formwork removal; In the layered casting, each layer is divided into a number of compartments, and the inner mold in each compartment adopts an integral structure. The compartments are connected by lifting and adjusting screws to form a demoulding state or a demoulding state; The template installation also includes a sealing process at the outer template, and the sealing process includes using rubber to form trapezoidal chamfers and rubber sealing strips at the top and bottom of the outer template respectively.

2. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 1 is characterized in that: The template installation includes bottom template installation, and the bottom template installation specifically forms a construction area with a fixed bottom template, and the movable bottom template is transported to a set position in the construction area by a module vehicle.

3. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 2 is characterized in that: The fixed bottom formwork includes a concrete foundation and a steel box beam, and the movable bottom formwork includes a steel box beam located on a jack and assembled through a steel cushion beam.

4. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 2 is characterized in that: It also includes a slurry leakage structure located outside the bottom mold, and the slurry leakage structure forms a semi-enclosed cavity extending obliquely from the outside to both sides of the end of the bottom mold.

5. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 1 is characterized in that: The template installation also includes the installation of side templates, specifically using arc segment templates and straight segment templates to splice together to form a lower barrel structure or an upper foundation structure.

6. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 5 is characterized in that: Tie rods are provided on the upper and lower sides of the side formwork, and the tie rods are pre-buried in the existing building or the constructed layer so that the tie rods form opposite tie rods.

7. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 1 is characterized in that: The order of installing the inner molds of the several compartments in the template installation is to install the middle first, then the surroundings, and finally the four corners, and after each inner mold is hoisted and installed, the inner mold is spread out.

8. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 1 is characterized in that: The length of the barrel foundation is less than or equal to 36-40m, and the length of the upper barrel body is less than the length of the lower foundation.

9. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 8 is characterized in that: The length of the lower foundation is 10-14m, and the lower structure is divided into at least 12 compartments.

10. The ultra-high and ultra-large asymmetric barrel foundation prefabrication process according to claim 8 is characterized in that: The upper barrel body is a rectangular structure with a width of 14-13.6m, and the rectangular structure is divided into at least compartments.

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