Method for sealing bottom of concrete under direct irrigation

Abstract

The invention discloses a method for sealing the bottom of concrete under direct injection water. The method comprises the following steps that construction is prepared; first seal condition acceptance; pouring construction is conducted through the first row of main guide pipes according to the prepared positions of the first row of main guide pipes to the last row of main guide pipes which are sequentially arranged in the cofferdam from upstream to downstream in advance; pouring construction is conducted through the second row of main guide pipes; pouring construction is conducted through the next row of main guide pipes till the last two rows of main guide pipes; pouring construction is conducted through the last row of main guide pipes; pouring construction is conducted through the last but one row of main guide pipes; and ending construction. The method has the beneficial effects that a novel method, namely a direct filling bottom sealing method, is adopted, and the defects that a traditional central concentrated feeding pouring period is long, procedures are complex, cross construction is more, and the concrete retarding requirement is high are overcome. By means of the method, the pouring speed is high, the pouring quality is high, equipment investment is small, functional areas are clear, cross-free construction is achieved, the single-time pouring amount is large, and the construction period is short.

Description

Technical Field

[0001] The present application belongs to the technical field of bridge foundation (or other underwater concrete foundation) construction, and specifically relates to a method for direct pouring underwater concrete bottom sealing, which is suitable for all underwater rapid bottom sealing construction, especially ultra-large underwater bottom sealing, which is more economical and efficient. Background Art

[0002] Bottom sealing construction is an important process for bridges or other structures to achieve water-proof and dry construction. In traditional bottom sealing construction, a pouring method using a pump truck to feed materials or a central collecting hopper to disperse materials is used. The bottom sealing construction is gradually completed through continuous feeding from the central collecting hopper.

[0003] Traditional backfill construction relies entirely on equipment placement. Due to site restrictions and limited equipment input, the backfill pouring speed is difficult to exceed 200m 3 / h; it is difficult to clearly divide the site into functional areas such as pouring area, traffic area, equipment area, etc., and cross-construction seriously affects the pouring speed of the bottom concrete. In recent years, it has exceeded 10,000m 3 There are more and more bottom sealing concrete structures, and the traditional bottom sealing technology is not suitable for the one-time pouring construction requirements of super-large bottom sealing concrete. It can only adopt the underwater compartment method to pour the bottom sealing concrete in blocks, which has a long construction period, complicated procedures and difficult to guarantee quality. Summary of the invention

[0004] The purpose of this application is to provide a method for direct pouring underwater concrete bottom sealing, which solves the construction difficulties or common problems limited by traditional bottom sealing technology, accelerates the bottom sealing construction speed, reduces construction risks, ensures the quality of bottom sealing casting, and realizes one-time high-quality and rapid completion of ultra-large-scale bottom sealing construction.

[0005] The purpose of this application is achieved through the following technical solutions:

[0006] A method for directly pouring underwater concrete bottom sealing comprises the following steps:

[0007] Step S01, construction preparation;

[0008] Step S02, first seal condition acceptance;

[0009] Step S03, according to the planned positions of the first row to the last row of main pipes arranged in sequence from upstream to downstream in the cofferdam in advance, casting construction is performed through the first row of main pipes;

[0010] Step S04, performing pouring construction through the second row of main pipes;

[0011] Step S05, pouring construction is performed through the next row of main pipes until the last two rows of main pipes;

[0012] Step S06, performing pouring construction through the last row of main pipes;

[0013] Step S07, performing pouring construction through the second to last row of main pipes;

[0014] Step S08, finishing construction.

[0015] Furthermore, the method generally adopts the full-platform direct injection method; the first sealing adopts the mobile hopper positioning plugging method; the first opening adopts the insertion method; the material replenishment adopts the multi-point balanced alternating direct injection method; the construction sequence is from upstream to downstream, and from the surroundings to the middle row by row.

[0016] Furthermore, the method includes an annular construction platform, a cofferdam is arranged inside the construction platform, a bottom-sealed working space is inside the cofferdam, a pouring platform is arranged between the upstream and downstream sides of the construction platform, and an annular one-way traffic path is formed between the construction platform and the pouring platform.

[0017] Furthermore, tower cranes, crawler cranes, truck pumps and sand and gravel pumps are arranged on the construction platform.

[0018] Furthermore, the first to twelfth rows of conduits are arranged in sequence from upstream to downstream in the cofferdam, the first, fourth, seventh, ninth and twelfth rows are main conduits, and the second, third, fifth, sixth, eighth, tenth and eleventh rows are spare conduits.

[0019] Furthermore, the first sealing adopts the mobile hopper positioning plugging method, and the first opening adopts the pipe insertion method; except for the first sealing and the first opening, all main pipe points adopt the direct filling method; each row of main pipe points adopts the alternating direct filling method.

[0020] Furthermore, when the seventh row of ducts is being poured, leveling is gradually carried out from the first row to the fourth row. When the twelfth row of ducts is being poured, leveling is gradually carried out from the fourth row to the seventh row. After the ninth row of ducts is poured, leveling is gradually carried out from the seventh row to the twelfth row.

[0021] Furthermore, the method also includes bottom measurement, which includes test measurement, pouring measurement, partition leveling measurement and slurry monitoring measurement. The bottom measurement also includes at least one of cofferdam monitoring measurement and platform scour monitoring measurement.

[0022] Furthermore, the test measurement contents are: measuring the elevation of the front and back concrete surfaces of the same steel casing at the same time;

[0023] The measurement contents of pouring measurement are: measurement of the initial bottom concrete surface elevation before the first sealing and opening; measurement of the buried depth of the conduit and the concrete thickness after the first sealing and opening; measurement of the current pouring row, the next row and the previous row monitoring during the pouring process. The current pouring row measurement content is the concrete surface elevation measurement, the next row measurement content is the concrete thickness measurement, and the previous row measurement content is the concrete surface elevation measurement after stopping pouring, before and after pipe removal; the measurement content on the river side and the bank side is the measurement of the concrete flow front line;

[0024] The measurement contents of the zone leveling measurement are: leveling the zone; after the two adjacent rows of main pouring points reach the designed elevation, the leveling density point measurement is carried out in the zone until the concrete filling is completed;

[0025] The measurement content of the floating slurry monitoring measurement is: when the front line of concrete flow reaches the second to last and last row of pipes for the first time, the muddy water in the downstream cofferdam is pumped out;

[0026] The measurement contents of the cofferdam monitoring measurement are: measuring the plane position and elevation of the four corners of the cofferdam;

[0027] The measurement contents of platform scour monitoring measurement are: measurement of mud surface elevation below the platform outside the upstream cofferdam, and observation of settlement of the platform, pier and cofferdam.

[0028] Furthermore, the finishing construction includes: re-measurement of the concrete top surface; removal of the conduit; dismantling of temporary facilities; and evacuation of equipment.

[0029] Principle of this application: The "direct pouring" bottom sealing method is to build a working platform on the cofferdam after the cofferdam and other supporting structures are put in place, and set up functional areas such as direct pouring area, vehicle traffic area, equipment area, and measurement area. The direct pouring conduit is arranged in advance in the direct pouring area, and a chute is set up away from the platform conduit to the platform to realize direct pouring; walking warning signs are set up in the vehicle traffic area; the auxiliary equipment stations are set up in advance in the equipment area; and the measuring area is equipped with a hammer in advance to monitor the bottom pouring elevation in real time. After the first seal is completed, the concrete can be poured directly into the water by a tank truck, eliminating the processes of pump truck feeding or aggregate hopper separation, significantly improving the pouring efficiency, significantly enhancing the overall quality of the bottom seal concrete, and achieving one-time high-quality and rapid completion.

[0030] Beneficial effects of the application: The new method - direct pouring and bottom sealing method is adopted to overcome the shortcomings of the traditional centralized feeding and pouring method, such as long pouring cycle, complex process, multiple cross-construction, and high requirements for concrete slow setting. Using this method, the pouring speed is fast, the pouring quality is high, the equipment investment is small, the functional area is clear and there is no cross-construction, the single pouring volume is large, and the construction period is short.

[0031] The aforementioned main scheme of the present application and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection in the present application; and in the present application, (non-conflicting options) can also be freely combined with each other and with other options. After understanding the scheme of the present application, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present application, and they are not exhaustively listed here. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the overall layout plan of this application.

[0033] Figure 2 It is the construction layout plan of this application.

[0034] Figure 3 It is a plan view of the catheter arrangement of this application.

[0035] Figure 4 It is a plan view of the conduit casting sequence of this application.

[0036] Figure 5 It is a plan view of the test measurement point layout of this application.

[0037] Figure 6 It is a plan view of the arrangement of the perfusion measurement points of this application.

[0038] In the figure: 001-construction platform, 002-cofferdam, 003-pouring platform, 004-conduit, 005-steel casing, 006-tower crane, 007-crawler crane, 008-truck pump, 009-sand and gravel pump; 1-12-the first to twelfth rows of conduits, Za-b-main conduits (a is 1, 4, 7, 9 or 12, b is 1-7), B1-45-spare conduits, S1-16-test measuring points, Cc-pouring measuring points (c is 011-019, 021-029...121-129). DETAILED DESCRIPTION

[0039] The following non-limiting examples are provided to illustrate the present application.

[0040] Embodiment 1:

[0041] refer to Figure 1 to Figure 6 As shown in the figure, a method of direct pouring underwater concrete bottom sealing is generally adopted. The method generally adopts the full platform direct pouring method; the first sealing adopts the mobile hopper positioning plugging method; the first opening adopts the insertion method; and the filling adopts the multi-point balanced alternating direct pouring method. The construction sequence is from upstream to downstream, and from the surrounding to the middle row by row.

[0042] The method includes a construction platform 001, a cofferdam 002, a pouring platform 003, a conduit 004, a steel casing 005, a tower crane 006, a crawler crane 007, a truck pump 008 and a sand and gravel pump 009.

[0043] Construction platform 001 is a U-shaped steel structure platform built in advance and above the water surface, serving as the basic working surface for construction. Construction platform 001 is equipped with cofferdam 002, which is also a U-shaped steel structure. The cofferdam 002 is a bottom-sealed working space. On the one hand, it is used to block the outflow of the bottom-sealed concrete to ensure that the bottom-sealed concrete in the cofferdam forms the designed geometric shape; on the other hand, it is used to block the water from the outside to prevent water from entering the bottom-sealed working space.

[0044] Two pouring platforms 003 along the river are provided between the upstream and downstream sides of the construction platform 001, through which the two sides of the construction platform are connected. The pouring platform 003 spans above the bottom cover working space, so that pouring operations and dedicated passages can be carried out above the pouring platform.

[0045] The shore and river sides of construction platform 001 are designated as equipment areas, the upstream and downstream sides of construction platform 001 and the middle of pouring platform 003 are designated as traffic areas, and the two sides of pouring platform 003 facing the river and the shore are designated as pouring areas. A circular one-way traffic path is formed between the upstream and downstream sides of construction platform 001 and the two pouring platforms 003, namely the traffic area, which enables one-way travel of concrete transport vehicles and facilitates pouring operations.

[0046] The upstream and downstream of construction platform 001 and the two pouring platforms 003 along the river in the cofferdam form a circular channel. A channel in the direction of the river is set up on the downstream side of construction platform 001 for vehicles to pass during the stage of pumping out floating slurry downstream of the sand and gravel pump. The channel in the cofferdam formed by pouring platform 003 is a three-lane channel. The middle lane of the three lanes is the main traffic lane. No unloading point shall be arranged, and concrete transport vehicles shall not be stranded in the middle lane. The lanes on both sides are pouring lanes, which are used for pouring after the transport vehicles are in place. All vehicles are one-way circulation to avoid traffic jams.

[0047] The concrete transport trucks gradually increase according to the pouring intensity. When the concrete transport trucks need to wait on site, they can wait in the free area of ​​construction platform 001 and pouring platform 003, but the number of transport trucks shall not exceed twice the number of holes (i.e. 1 for use and 1 for standby). On-site transport trucks shall not park on the deck of the navigation trestle. If they really need to stop and wait temporarily, the front and rear clearance of two vehicles shall not be less than 15m. The equipment area of ​​construction platform 001 is arranged with tower crane 006, crawler crane 007, automobile pump 008 and sand and gravel pump 009. The main equipment arranged in the equipment area is 2 tower cranes (1# and 2# 600t.m tower cranes), 4 crawler cranes (1# 200t crawler crane, 2~4# 135t crawler cranes), and 4 automobile pumps (except 3# with a 47m arm length, the rest are 62m arm length). There are 4 sand and gravel pumps, 1 each at the corners on the shore side and the river side, and 2 in the middle. The standby generator is arranged next to the box transformer, and the standby pump truck is parked outside the trestle. The river and shore side platforms of construction platform 001 are equipment areas, where crawler cranes and truck pumps are parked. They are used for the first opening and sealing of the duct. The crawler cranes are also used to lift the circulating ducts, and the truck pumps are also used to assist in laying materials.

[0048] The first to twelfth rows of conduits (corresponding to numbers 1 to 12) are arranged in sequence from upstream to downstream in the cofferdam. All conduit points meet the requirements of direct unloading by the conveyor truck or channel chute. The first, fourth, seventh, ninth and twelfth rows are main conduits, and the second, third, fifth, sixth, eighth, tenth and eleventh rows are spare conduits. The construction sequence is the first, fourth, seventh, twelfth and ninth rows of conduits. When the main conduit pouring effect is not good, the spare conduits are used around the corresponding positions for remediation.

[0049] The diffusion radius of the conduit is 7m. The conduit layout rule: the main conduit is 100cm away from the cofferdam and at the intersection of the diagonal lines of the casing. The number of conduits: 35 main conduits in 5 rows and 7 columns (corresponding to the labels Za-b, a is 1, 4, 7, 9 or 12, b is 1 to 7), 45 spare conduits (corresponding to the labels B1 to 45), a total of 80.

[0050] Duct installation: a total of 28 sets of ducts in the first, fourth, seventh and twelfth rows are installed in place before bottom sealing; the first sealed duct is less than 20cm from the bottom; the first opened duct in the first row is 60cm from the bottom; the fourth row duct is more than 200cm from the bottom; the remaining ducts are more than 500cm from the bottom (the first seal means there is no concrete at this location and the first concrete is poured; the first opening means the concrete has already flowed to this location but this location is poured with concrete for the first time, that is, the first seal is the first row and the first opening is the remaining rows).

[0051] The method comprises the following steps: Step S01, construction preparation. Step S02, first sealing condition acceptance.

[0052] Step S03, according to the planned positions of the first row to the last row of main conduits arranged in sequence from upstream to downstream in the cofferdam in advance, casting construction is performed through the first row of main conduits (ie, the first row of conduits 1).

[0053] Construction sequence: 2 first closures (Z1-1, Z1-7), 5 first openings; the first closure sequence is Z1-1 and Z1-7, which can be closed simultaneously. The first opening sequence is Z1-2→Z1-3→Z1-4, Z1-6→Z1-5.

[0054] Construction standards: The flatness of the concrete surface at the bottom of the first sealed conduit must meet the requirement of 10cm, and the height of the conduit from the bottom shall not exceed 20cm. If there is no leveling layer at the bottom of the pit, an anti-collision steel plate shall be added to the bottom of the conduit; no less than 6 trucks of concrete shall be in place before the first sealing of a single conduit, and continuous pouring shall be carried out after the plug is pulled out; the first opening shall meet the requirement that the concrete thickness at the conduit is greater than 50cm, and the conduit mouth shall not be more than 10cm away from the concrete surface; the concrete in the first opening hopper drops to the bottom of the hopper and the conduit is inserted, with a depth of 30cm; when the first sealing or opening is carried out, the main hook of the crawler crane suspends the middle hopper and the auxiliary hook suspends the plug-pulling plate; the buried depth of the conduit shall be measured in time after the first sealing or opening, and a small hopper shall be replaced for continuous feeding after the buried depth stabilizes; during normal pouring, the concrete suspension time of the conduit hole shall not exceed 30min, and the conduit shall be controlled according to the maximum buried depth of 300cm and the minimum buried depth of 50cm; when the concrete reaches the design elevation, the pouring shall be stopped for 1h and the conduit can be removed only after the concrete surface is stable.

[0055] Construction technology: The first sealing adopts the "mobile hopper positioning plugging method", and the first opening adopts the "insertion method"; except for the first sealing and the first opening, all main pipe points adopt the direct irrigation method; each row of main pipe points adopts the alternating direct irrigation method.

[0056] Equipment layout: The first sealing and first opening both use 1~4 pump trucks + 1~4 crawler cranes; the first sealing uses 19m 3 Large hopper +5m 3 The middle hopper is 3m 3 Middle hopper; crawler crane or tower crane can be used to put the conduit in place; the positions of pump truck and crawler crane are shown in the figure; during the continuous pouring stage, it is recommended that the conveyor truck adopts 1+1 configuration (1 for pouring, 1 for waiting) to ensure orderly organization on site.

[0057] Concrete supply: The first closure uses self-built station concrete, with emphasis on testing concrete performance indicators such as concrete slump, diffusion, and air content before and after leaving the station; the number of direct pouring is gradually increased from 1 to 7, with 4 truck-mounted pumps, and concrete production and transportation are adjusted according to the on-site pouring strength; after the first closure, the amount of concrete supplied by the commercial concrete station is determined based on the pouring strength; the truck-mounted pumped concrete is mainly self-built station concrete; because the intermediate duct point chute is located on the shore side, the concrete supply is tilted toward the shore side.

[0058] Construction measurement: concrete front line measurement; when the first row of concrete reaches the design elevation, carry out test measurement.

[0059] Step S04, performing pouring construction through the second row of main conduits (ie, the fourth row of conduits 4).

[0060] Construction sequence: The first opening order is Z4-2 and Z4-3 after Z4-1, and Z4-6 and Z4-5 after Z4-7. The specific first opening order is determined according to the site conditions.

[0061] Construction standards: The first opening standard is that the concrete thickness at the fourth row of ducts is greater than 1m; the first opening pipe insertion standards, hopper plug suspension, normal pouring and pipe removal requirements are the same as the first row.

[0062] Construction technology: The construction technology is the same as that of the first row of ducts; continue to pay attention to the flow position of concrete; pay attention to the use of sand and gravel pumps to pump out mud and water when the concrete front line reaches the eleventh row, and pump out floating slurry when it reaches the twelfth row.

[0063] Equipment layout: Except for the crawler crane in the two pump workshops which can be moved as needed, the positions of other equipment remain unchanged; the lifting and hoisting equipment, the first opening concrete pumping equipment, the first opening middle hopper, and the direct filling method after the first opening are all the same as the first row of first opening; the sand and gravel pump is activated to pump out the floating slurry as needed.

[0064] Concrete supply: direct pouring points gradually increased from 7 points (first row) to 14 points (first row and fourth row), and 4 truck pumps started pumping concrete or maintaining pumps for the first time; concrete supply entered the normal supply stage, and the three mixing stations supplied materials normally, focusing on concrete production and transportation matters; strengthening the control of performance indicators such as concrete slump, slump and air content before leaving the station and after arriving at the site.

[0065] Construction measurement: The fourth row of concrete reaches the design elevation, and test measurements and leveling measurements are conducted within the range of the first to fourth rows.

[0066] Step S05, casting construction is performed through the next row of main conduits until the last two rows of main conduits, specifically the seventh row of conduits 7, are cast.

[0067] Construction sequence: The first opening sequence is the same as the fourth row requirements, that is, the first opening sequence is Z7-2 and Z7-3 after Z7-1, and Z7-6 and Z7-5 after Z7-7. The specific first opening sequence is determined according to the site conditions.

[0068] Construction standards: The concrete thickness at the seventh row of ducts is greater than 1m; the requirements for the first opening of the pipe, hopper plug suspension, normal pouring and pipe removal are the same as those for the first row.

[0069] Construction technology: The construction technology is the same as the first row; continue to pay attention to the twelfth row of concrete slurry. If there is sedimentation, organize the tower crane to suspend and pump it out in time; start to gradually advance the leveling from the first row to the fourth row.

[0070] Equipment layout: The truck pumps are relocated, and before the first opening of the seventh row, the 2# and 4# pump trucks are moved to the downstream corner point, and the 1# and 3# pump trucks are moved to the fifth row; the crawler crane can be moved as needed in the two pump workshops; the lifting and hoisting equipment, the first opening concrete pumping equipment, the first opening middle hopper, and the direct filling method after the first opening are the same as the first opening of the fourth row; the sand and gravel pump is used to pump out the slurry as needed; the tower crane is used to suspend the mobile pumping when the slurry is pumped out, and a hoist is used to hang on the cofferdam wall when the pumping is stopped.

[0071] Concrete supply: The number of on-site pouring points and pouring methods remain basically unchanged, and the concrete supply and concrete performance index control remain the same as the fourth row.

[0072] Construction measurement: The seventh row of concrete reaches the design elevation, and test measurements and leveling measurements are conducted within the range of the fourth to seventh rows.

[0073] Step S06, performing pouring construction through the last row of main conduits (ie, the twelfth row of conduits 12).

[0074] Construction sequence: The initial order is Z1-1→Z1-2→Z1-3→Z1-4, Z1-7→Z1-6→Z1-5.

[0075] Construction standards: The concrete thickness at the twelfth row of pipes is greater than 50cm; the requirements for the first opening of pipes, hopper plug suspension, normal pouring and pipe removal are the same as those for the first row.

[0076] Construction technology: The construction technology is the same as that of the first row. Before the first opening, a special person is responsible for organizing the pumping of floating slurry to the concrete surface. The pumping method is the same as that of the seventh row. Start leveling gradually from the fourth row to the seventh row.

[0077] Equipment layout: Equipment layout is the same as the seventh row.

[0078] Concrete supply: Concrete supply is the same as that of the seventh row, and concrete quality control continues to be strengthened.

[0079] Step S07, performing pouring construction through the second to last row of main conduits (ie, the ninth row of conduits 9).

[0080] Construction sequence: The first opening sequence is the same as that of the seventh row, that is, the first opening sequence is Z9-2 and Z9-3 after Z9-1, and Z9-6 and Z9-5 after Z9-7. The specific first opening sequence is determined according to the site conditions.

[0081] Construction standards: The concrete thickness at the ninth row of pipes is greater than 1m; the requirements for the first pipe insertion standard, hopper plug suspension, normal pouring and pipe removal are the same as those for the first row.

[0082] Construction technology: The process standards and requirements of the first opening pipe insertion method, middle hopper feeding method, plug pulling suspension method, normal pouring, mud extraction, etc. are the same as those of the first opening of the seventh row.

[0083] Equipment layout: The functions and positioning of other equipment are the same as those of the seventh row.

[0084] Concrete supply: The amount of direct concrete pouring will be gradually reduced, and the amount of concrete supplied by commercial concrete mixing stations will be gradually controlled; the control of concrete production, transportation and performance indicators is the same as the fourth row.

[0085] The method also includes bottom cover measurement, which includes test measurement, pouring measurement, partition leveling measurement, slurry monitoring measurement, cofferdam monitoring measurement and platform scour monitoring measurement.

[0086] The test points are divided into two groups. The first group of points is arranged on the downstream side of 41, 42, 43, 44# steel casings (corresponding to the number S1~8), and the second group of points is arranged on the downstream side of 27, 28, 29, 30# steel casings (corresponding to the number S9~16). The test measurement content is: the front and back concrete surface elevations of the same steel casing are measured at the same time. The measurement time is from the pouring of the first row (Z1) to the seventh row (Z7) reaching the design elevation, and the monitoring frequency is 2h / time.

[0087] Arrangement of grouting measuring points: Arrangement rules: the catheter point also serves as the measuring point, one measuring point is arranged on the downstream side of each casing, measuring points are arranged on the inner wall of the cofferdam corresponding to the casing position and the four corner points, and local encrypted measuring points are temporarily arranged; Number of measuring points: 80 catheter points, 117 section measuring points, 16 catheter points and measuring points overlap, a total of 181 measuring points (corresponding to label Cc, c is 011~019, 021~029...121~129).

[0088] The measurement contents of the main pouring point measurement are: measurement of the initial bottom concrete surface elevation before the first sealing and the first opening; measurement of the buried depth of the conduit and the concrete thickness after the first sealing and the first opening; measurement of the current pouring row, measurement of the next row and monitoring measurement of the previous row during the pouring process. The measurement content of the current pouring row is the measurement of the concrete surface elevation, the measurement content of the next row is the measurement of the concrete thickness, and the measurement content of the previous row is the measurement of the concrete surface elevation after stopping pouring, before and after pipe removal.

[0089] The measurement content of the concrete flow front line measurement point is: measure on both sides of the railings of the channel platform on the river side and the bank side, and find the cross-section position where the concrete thickness reaches 20cm; the measurement frequency is 2h / time.

[0090] The measurement contents of zone leveling measurement are: Leveling zone: divided into 3 zones, Zone 1 is the first to fourth rows, Zone 2 is the fourth to seventh rows, Zone 3 is the seventh to twelfth rows; Measurement time: After the main pouring points of two adjacent rows reach the design elevation, leveling encryption point measurements are carried out within the zone until the concrete filling is completed; The measurement frequency is 2h / time.

[0091] The measurement content of the slurry monitoring measurement is: when the front line of concrete flow reaches the second to last row (eleventh row) and the last row (twelfth row) of ducts for the first time, notify the on-site person in charge to organize the pumping of mud and water in the downstream cofferdam.

[0092] The cofferdam monitoring measurement includes: measuring the plane position and elevation of the four corners of the cofferdam. The measurement frequency is to measure the cofferdam posture once before the bottom casting, during the casting (the second day after the opening), and after the casting, for a total of 3 times.

[0093] The platform scour monitoring measurement includes: measurement of mud surface elevation below the platform outside the upstream cofferdam, and observation of settlement of the platform, trestle and cofferdam. The measurement frequency is once a day.

[0094] The pouring process also includes leveling construction. The order of leveling is: Zone 1 → Zone 2 → Zone 3; Zone 1, that is, when the fourth row is poured to the design elevation, start leveling from the first row to the fourth row; Zone 2, that is, when the seventh row is poured to the design elevation, start leveling from the fourth row to the seventh row; Zone 3, that is, after the twelfth and ninth rows are poured to the design elevation, start leveling from the seventh row to the twelfth row; when it does not affect the first opening, use a pump truck to add material from upstream to downstream row by row.

[0095] Leveling and filling method: After the sections of two adjacent main conduit points reach the designed elevation, the height difference of the concrete surface between the two sections shall be measured more frequently. If the height difference is not greater than 30cm, it is recommended not to do leveling, and only level individual points with large height differences (more than 50cm). For points below 50cm outside the casting platform, the suspended pipe method shall be used for leveling. For points below 50cm under the casting platform, the leveling method shall be decided after temporary research.

[0096] Construction technology: The method of inserting pipes for material replenishment is the same as the method of first opening pipes at the main pouring point; the replenishment material is pumped by a pump truck to control the volume of pumped concrete replenishment material.

[0097] Equipment layout: crawler cranes are used for hoisting and concrete feeding is carried out by truck pumps. The equipment is located at the same location as the main pouring point. Concrete supply: self-built concrete supply is recommended for all supplementary concrete. Measurement: leveling measurement is performed in different areas.

[0098] Step S08, finishing construction: Re-measurement of the concrete top surface: The surveyor re-measures the elevation and flatness of the bottom concrete surface to ensure that it meets the design requirements; Pulling out the conduit: After the concrete pouring at the conduit point is completed, the crane pulls out the conduit or lifts it up and suspends it at least 2m above the concrete surface. After pulling it out, the conduit is cleaned and removed in time; Dismantling of temporary facilities: Dismantle temporary facilities in reverse order to strengthen safety management and control; Equipment evacuation: Equipment arranged on site is gradually evacuated from the site according to construction and production needs.

[0099] In a real project, the outer contour plane size of the main pier cofferdam is 80.6m×52.6m, the total height is 42.75m, and the bottom casting volume is 21800m 3 , continuous pouring for 36 hours, the pouring is completed, the average pouring strength is 605m 3 / h, the maximum pouring intensity during peak period reaches 780m 3 / h. The new construction method significantly speeds up the pouring speed, greatly improves the construction efficiency, and significantly improves the quality of the cofferdam bottom concrete. One-time continuous pouring of 21,800m 3 The back cover is a world first!

[0100] The aforementioned basic examples and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection in this application. In the scheme of this application, each selected example can be arbitrarily combined with any other basic examples and selected examples.

[0101] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for direct pouring underwater concrete bottom sealing, It is characterized in that The steps include: Step S01, construction preparation; Step S02, first seal condition acceptance; Step S03, according to the planned positions of the first row to the last row of main pipes arranged in sequence from upstream to downstream in the cofferdam in advance, casting construction is performed through the first row of main pipes; Step S04, performing pouring construction through the second row of main pipes; Step S05, pouring construction is performed through the next row of main pipes until the last two rows of main pipes; Step S06, performing pouring construction through the last row of main pipes; Step S07, performing pouring construction through the second to last row of main pipes; Step S08, finishing construction.

2. The direct-irrigation underwater concrete bottom sealing method according to claim 1, Features: This method generally adopts the full-platform direct injection method; the first sealing adopts the mobile hopper positioning plugging method; the first opening adopts the insertion method; the material replenishment adopts the multi-point balanced alternating direct injection method; the construction sequence is from upstream to downstream, and from the surroundings to the middle row by row.

3. The direct-irrigation underwater concrete bottom sealing method according to claim 1, Features: The method comprises an annular construction platform (001), wherein a cofferdam (002) is arranged inside the construction platform (001), a bottom-sealed working space is arranged inside the cofferdam (002), a pouring platform (003) is arranged between the upstream side and the downstream side of the construction platform (001), a circular one-way passage is formed between the construction platform (001) and the pouring platform (003), and a passage for vehicles to pass in the cross-river direction is arranged on the downstream side of the construction platform (001).

4. The direct-irrigation underwater concrete bottom sealing method according to claim 3, Features: The platform near the river and the shore of the construction platform (001) is the equipment area. A tower crane (006), a crawler crane (007), a truck pump (008) and a sand and gravel pump (009) are arranged on the construction platform (001).

5. The direct-irrigation underwater concrete bottom sealing method according to claim 1, Features: The first to twelfth rows of ducts are arranged in sequence from upstream to downstream in the cofferdam. The first, fourth, seventh, ninth and twelfth rows are main ducts, and the second, third, fifth, sixth, eighth, tenth and eleventh rows are spare ducts. All duct points meet the requirements of direct unloading by conveying vehicles or self-unloading by channel chutes.

6. The direct-irrigation underwater concrete bottom sealing method according to claim 5, Features: The first sealing adopts the mobile hopper positioning plugging method, and the first opening adopts the insertion method; Except for the first sealing and first opening, all main pipe points adopt direct irrigation method; Alternating direct irrigation method is adopted for each row of main pipe points.

7. The direct-irrigation underwater concrete bottom sealing method according to claim 5, Features: When pouring the seventh row of ducts, leveling is carried out step by step from the first row to the fourth row. When pouring the twelfth row of ducts, leveling is carried out step by step from the fourth row to the seventh row. After the pouring of the ninth row of ducts is completed, leveling is carried out step by step from the seventh row to the twelfth row.

8. The direct-irrigation underwater concrete bottom sealing method according to claim 1, Features: The method also includes bottom cover measurement, which includes test measurement, pouring measurement, partition leveling measurement and slurry monitoring measurement. The bottom cover measurement also includes at least one of cofferdam monitoring measurement and platform scour monitoring measurement.

9. The direct-irrigation underwater concrete bottom sealing method according to claim 8, Features: The test measurement content is: measuring the elevation of the front and back concrete surfaces of the same steel casing at the same time; The measurement contents of pouring measurement are: measurement of the initial bottom concrete surface elevation before the first sealing and opening; measurement of the buried depth of the conduit and the concrete thickness after the first sealing and opening; measurement of the current pouring row, the next row and the previous row monitoring during the pouring process. The current pouring row measurement content is the concrete surface elevation measurement, the next row measurement content is the concrete thickness measurement, and the previous row measurement content is the concrete surface elevation measurement after stopping pouring, before and after pipe removal; the measurement content on the river side and the bank side is the measurement of the concrete flow front line; The measurement contents of the partition leveling measurement are: leveling the partition; After the main filling points of two adjacent rows reach the designed elevation, the leveling and density point measurements are carried out in the partition until the concrete filling is completed; The measurement content of the floating slurry monitoring measurement is: when the front line of concrete flow reaches the second to last and last row of pipes for the first time, the muddy water in the downstream cofferdam is pumped out; The measurement contents of the cofferdam monitoring measurement are: measuring the plane position and elevation of the four corners of the cofferdam; The measurement contents of platform scour monitoring measurement are: measurement of mud surface elevation below the platform outside the upstream cofferdam, and observation of settlement of the platform, pier and cofferdam.

10. The direct-irrigation underwater concrete bottom sealing method according to claim 1, Features: The finishing construction includes: re-measurement of concrete top surface; removal of conduit; dismantling of temporary facilities; and evacuation of equipment.

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