CN112252349A - Sinking construction method without drainage for open caisson - Google Patents
Sinking construction method without drainage for open caisson Download PDFInfo
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- CN112252349A CN112252349A CN202010950466.3A CN202010950466A CN112252349A CN 112252349 A CN112252349 A CN 112252349A CN 202010950466 A CN202010950466 A CN 202010950466A CN 112252349 A CN112252349 A CN 112252349A
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- open caisson
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- pipe
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D23/00—Caissons; Construction or placing of caissons
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D23/00—Caissons; Construction or placing of caissons
- E02D23/08—Lowering or sinking caissons
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D23/00—Caissons; Construction or placing of caissons
- E02D23/08—Lowering or sinking caissons
- E02D23/14—Decreasing the skin friction while lowering
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- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
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- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The application relates to a non-drainage sinking construction method for an open caisson, which comprises the following steps: s1, water jetting pipes are arranged along the periphery of the open caisson, water is sprayed to soil around the open caisson at high pressure, and the soil in the side wall area of the open caisson is cut and softened; s2, spraying water into the open caisson at high pressure, punching soil at the bottom of the open caisson by high-pressure water, digging the bottom of the open caisson into a pot bottom shape with a concave center, mixing the soil and water to form slurry, pumping the slurry out of the open caisson, and squeezing the soil at the blade foot of the open caisson to sink; s3, spraying water at high pressure to the soil body in the newly sinking area of the open caisson through a water injection pipe in a sectional water injection mode when the open caisson sinks for a certain distance; s4, after the open caisson is sunk to the designed position, grouting is carried out on the soil outside the open caisson by a water jet pipe in a retreating type sectional grouting mode, and the soil outside the open caisson is reinforced; and S5, performing concrete bottom sealing on the bottom of the open caisson. The construction method of non-drainage sinking can reduce the problems of inclination, sudden sinking and water burst when the open caisson sinks.
Description
Technical Field
The application relates to the field of open caisson construction, in particular to a non-drainage sinking construction method for an open caisson.
Background
Open caisson is a construction process commonly used in underwater construction. The construction method is mainly used for bridge foundation construction, and has the forms of square, round, oval and the like, a first section is poured in advance during construction, the lower part is hollowed after solidification, a concrete block begins to sink, the upper part is continuously poured, the upper part is hollowed again after completion, and the steps are sequentially circulated until the bottom of a foundation is excavated.
In the traditional sinking process of the open caisson during drainage and sinking of the large open caisson with poor soil quality and high water content, accidents such as inclination, sudden sinking, water burst at the bottom of the well, sand burst and the like often occur. Therefore, designing a sinking construction method without drainage for the open caisson to prevent the above accidents and improve the sinking construction efficiency of the open caisson becomes a technical problem to be solved urgently by technical personnel in the technical field.
Disclosure of Invention
In order to solve the technical problems of inclination, sudden sinking and water burst of the conventional open caisson drainage sinking method, the application provides a non-drainage sinking construction method for the open caisson.
The application provides a construction method for sinking of open caisson without drainage, which adopts the following technical scheme:
a sinking construction method without water drainage for open caisson comprises the following steps:
s1, water jetting pipes are arranged along the periphery of the open caisson, and water is jetted to soil around the open caisson at high pressure in a sectional water injection mode to cut and soften the soil in the side wall area of the open caisson;
s2, spraying water into the open caisson at high pressure, punching soil at the bottom of the open caisson by high-pressure water, digging the bottom of the open caisson into a pot bottom shape with a concave center, mixing the soil and water to form slurry, pumping the slurry out of the open caisson, and squeezing the soil at the blade foot of the open caisson to sink;
s3, spraying water at high pressure to the soil body in the newly sinking area of the open caisson through a water injection pipe in a sectional water injection mode when the open caisson sinks for a certain distance;
s4, after the open caisson is sunk to the designed position, grouting is carried out on the soil outside the open caisson by a water jet pipe in a retreating type sectional grouting mode, and the soil outside the open caisson is reinforced;
and S5, performing concrete bottom sealing on the bottom of the open caisson.
By adopting the technical scheme, the method ensures the water pressure inside and outside the open caisson in the open caisson sinking process by using the non-drainage sinking method, and reduces the problems of water burst, sand burst and the like in the open caisson sinking process; in addition, before the open caisson begins to sink, a water jetting pipe is arranged around the open caisson, soil outside the wall of the open caisson is cut and softened in advance, resistance of the soil outside the open caisson to the sinking of the open caisson is reduced, the open caisson is slightly influenced by external resistance, and the open caisson can sink uniformly; then, the sinking of the open caisson without drainage is realized by matching high-pressure water spraying and pumping drainage of a slurry pump, the sinking efficiency of the open caisson is improved, and the open caisson is ensured to sink uniformly;
and moreover, the water jetting pipe sprays water to disturb and soften the soil outside the open caisson, so that the friction force between the soil and the open caisson is reduced, after the open caisson sinks to a design position, the fixing capacity of the soil to the open caisson is weakened, the open caisson is easily caused to continuously sink, and the sinking amount exceeds a design range.
Preferably, a water injection hole is formed in one half of the pipe wall of the water injection pipe close to the side wall of the open caisson.
By adopting the technical scheme, the water jetting hole is formed in one side, close to the open caisson, of the water jetting pipe, so that the phenomenon that when soil is softened, the water jetting pipe is completely softened all around is avoided, and the soil around the water jetting pipe is moved together when the open caisson sinks.
Preferably, the plurality of water jetting holes are arranged along the circumferential direction of the water jetting pipe at intervals, and a plurality of lines are arranged along the length direction of the water jetting pipe, the distance between every two adjacent water jetting holes is 5-10mm, the distance between every two adjacent water jetting holes is 10-15mm, and the diameter of each water jetting hole is 1 mm.
By adopting the technical scheme, the water injection hole with the diameter of 1mm meets the requirement of outwards spraying water, and the water injection pipe can be prevented from being blocked by soil outside the water injection pipe; in addition, the water spraying amount is controlled, and the influence on the sinking of the open caisson caused by excessive softening of a soil body sprayed with water is avoided.
Preferably, the step S1 of injecting water in sections is inserting a grouting pipe into the water jet pipe, wherein a sealing plug is sleeved at an end of the grouting pipe inserted into the water jet pipe at an interval, the sealing plug is sealed in the water jet pipe in a sliding manner, and the high-pressure water is sprayed out from the designated area of the water jet pipe through a grout outlet on the grouting pipe.
Through adopting above-mentioned technical scheme, carry out the fixed point water spray to the injection pipe through the slip casting pipe, avoid the soil body that softens to spray water many times and soften, cause the soil body excessively to soften, sink to cause the influence to the open caisson.
Preferably, the caisson water level is maintained above the groundwater level in step S2.
By adopting the technical scheme, the phenomena of sinking inclination, sand gushing and water gushing of the open caisson caused by the fact that sand, stone and muddy water outside the open caisson flow into the open caisson are avoided.
Preferably, in step S2, the central scouring depth of the bottom of the open caisson is not more than 1.0m, and the width of the soil ridge of the edge foot around the open caisson is 80 cm.
By adopting the technical scheme, the open caisson is ensured to sink uniformly and stably.
Preferably, in step S3, when the open caisson sinks for 1-2m, high-pressure water is sprayed to the soil mass in the newly sunk area of the open caisson through the water injection pipe in a segmented water injection manner.
By adopting the technical scheme, the problems that the sunk well sinks too much, the friction force between un-softened soil and the sunk well is too large, the stress of the sunk well is uneven, and the sunk well sinks obliquely are avoided.
Preferably, in step S4, the soil body is grouted by using a grouting pipe.
By adopting the technical scheme, the grouting pipe is adopted for water injection and grouting, and the operation is convenient.
Preferably, the grouting slurry is a cement-water glass double slurry.
Through adopting above-mentioned technical scheme, spout the two thick liquids of muddy water glass in to the disturbance soil body through the penetrating pipe, make the soil body solidify fast, closely knit and two thick liquids with the adhesion between soil body and the open caisson, increase the interlock ability of open caisson and soil body, increase the frictional force between soil body and the open caisson, improve the fixed ability to the open caisson, reduce the open caisson from sinking.
In summary, the present application includes at least one of the following beneficial technical effects:
according to the method, before the open caisson begins to sink, the water injection pipe is arranged around the open caisson, so that soil outside the wall of the open caisson is cut and softened in advance, the resistance of the soil outside the open caisson to the sinking of the open caisson is reduced, the influence of external resistance on the open caisson is small, and the open caisson can sink uniformly; and then the non-drainage sinking of the open caisson is realized by matching the high-pressure water spray and the pumping drainage of a slurry pump, the sinking efficiency of the open caisson is improved, and the open caisson is ensured to sink uniformly.
In addition, the water jetting pipe jets water to disturb and soften the soil outside the open caisson, so that the friction force between the soil and the open caisson is reduced, after the open caisson sinks to a design position, the fixing capacity of the soil to the open caisson is weakened, the open caisson is easily caused to continuously sink, and the sinking amount exceeds a design range.
Detailed Description
The present application is described in further detail below.
The embodiment of the application discloses a construction method for sinking an open caisson without draining water. The sinking construction method without water drainage for the open caisson comprises the following steps:
and S1, drilling holes along the periphery of the open caisson, drilling a water injection pipe into the drilled holes, and drilling the water injection pipe until the designed bottom elevation of the open caisson is reached. The half pipe wall of the water jetting pipe close to the side wall of the open caisson is provided with a plurality of water jetting holes along the circumferential direction of the water jetting pipe, and the water jetting pipes are provided with a plurality of rows along the length direction of the water jetting pipe, the distance between every two adjacent water jetting holes is 5-10mm, the distance between every two adjacent water jetting holes is 10-15mm, the diameter of each water jetting hole is 1mm, the water jetting holes with the diameter of 1mm meet the requirement of outwards spraying water, and the water jetting pipe can be prevented from being blocked by soil outside the water jetting pipe; in addition, the water spraying amount is controlled, and the influence on the sinking of the open caisson caused by excessive softening of a soil body sprayed with water is avoided.
Water spraying: and a sectional water injection mode is adopted, water is injected into the wall area of the open caisson, high-pressure water injection is adopted during water injection, the water injection pressure is not lower than 1.2Mpa, high-pressure water is sprayed out from the water injection holes, the soil outside the open caisson is cut and disturbed, the soil is softened, the friction force between the open caisson and the surrounding soil is reduced, and the open caisson can sink uniformly. The injection pipe is inserted into the water injection pipe, the sealing plug is arranged at the interval sleeve of one end of the water injection pipe, the sealing plug is arranged in the water injection pipe and can seal the water injection pipe, a plurality of slurry outlet holes are formed in the area, located between the two sealing plugs, of the injection pipe, the injection pipe is inserted into the area to be sprayed with water, and high-pressure water spraying is carried out.
And S2, injecting water into the open caisson at high pressure to keep the water level in the open caisson above the underground water level line, so as to prevent the internal pressure of the open caisson from being small, and prevent a large amount of external slurry mixture from flowing into the open caisson, wherein the water injection pressure is not lower than 1.2 Mpa. And punching the soil body at the bottom of the open caisson by using high-pressure water through a water gun nozzle, mixing the soil body with water to form slurry, and discharging the slurry out of the open caisson by using a slurry pump. When the water gun nozzle punches the soil body, the bottom of the open caisson is dug into a semi-ellipsoid shape with a concave center (namely, the bottom of the open caisson is dug into a big bottom shape with a concave center), the central scouring depth of the bottom of the open caisson is not more than 1.0m, the soil ridges of the cutting edges at the periphery of the bottom of the open caisson are kept at 80cm, and meanwhile, the water quantity injected into the open caisson by the high-pressure water gun is controlled to be consistent with the mud pumping quantity of the mud pump. When the water gun nozzle is washed, the sunk well is sunk by squeezing soil at the blade foot.
And S3, spraying water to the soil body of the newly-sunk area of the open caisson through the water injection pipe by using a sectional water injection mode every time the open caisson sinks for 1-2m, and cutting and softening the soil body. And repeating the step S3 to continue sinking the open caisson.
S4, after the open caisson is sunk in place, keeping the water level in the open caisson to be higher than the underground water level line, determining the thickness of bottom sealing concrete, excavating the soil body under the bottom plate to the depth required by the thickness of the bottom sealing, arranging the diver to touch and arrange the bottom, flushing and contacting the bottom sealing concrete with the edge foot face slurry, and continuously observing for 8 hours after cleaning.
During observation, a retreating sectional grouting mode is adopted, high-pressure grouting is carried out on soil bodies in the wall area of the open caisson through a grouting pipe, cement-water glass double grout is adopted as grout, the solidification efficiency of the cement grout is increased, the soil bodies on the outer wall of the open caisson are reinforced, the friction force between the soil bodies and the open caisson is increased, and the self-sinking amount of the open caisson is reduced.
And S5, when the sinking amount is less than 10mm, throwing and filling a crushed stone cushion layer with the thickness of 25cm-30cm into the open caisson, and pouring underwater concrete into the open caisson by adopting a guide pipe normal direction for bottom sealing.
According to the method, before the open caisson begins to sink, the water injection pipe is arranged around the open caisson, so that soil outside the wall of the open caisson is cut and softened in advance, the resistance of the soil outside the open caisson to the sinking of the open caisson is reduced, the influence of external resistance on the open caisson is small, and the open caisson can sink uniformly; and then the non-drainage sinking of the open caisson is realized by matching the high-pressure water spray and the pumping drainage of a slurry pump, the sinking efficiency of the open caisson is improved, and the open caisson is ensured to sink uniformly.
In addition, the water jetting pipe jets water to disturb and soften the soil outside the open caisson, so that the friction force between the soil and the open caisson is reduced, after the open caisson sinks to a design position, the fixing capacity of the soil to the open caisson is weakened, the open caisson is easily caused to continuously sink, and the sinking amount exceeds a design range.
The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (9)
1. The non-drainage sinking construction method of the open caisson is characterized by comprising the following steps of:
s1, water jetting pipes are arranged along the periphery of the open caisson, and water is jetted to soil around the open caisson at high pressure in a sectional water injection mode to cut and soften the soil in the side wall area of the open caisson;
s2, spraying water into the open caisson at high pressure, punching soil at the bottom of the open caisson by high-pressure water, digging the bottom of the open caisson into a pot bottom shape with a concave center, mixing the soil and water to form slurry, pumping the slurry out of the open caisson, and squeezing the soil at the blade foot of the open caisson to sink;
s3, spraying water at high pressure to the soil body in the newly sinking area of the open caisson through a water injection pipe in a sectional water injection mode when the open caisson sinks for a certain distance;
s4, after the open caisson is sunk to the designed position, grouting is carried out on the soil outside the open caisson by a water jet pipe in a retreating type sectional grouting mode, and the soil outside the open caisson is reinforced;
and S5, performing concrete bottom sealing on the bottom of the open caisson.
2. The non-drainage sinking construction method of the open caisson according to claim 1, wherein: and a water injection hole is formed in the half pipe wall of the water injection pipe close to the side wall of the open caisson.
3. The non-drainage sinking construction method of the open caisson according to claim 2, wherein: the water injection holes are arranged along the circumferential direction of the water injection pipe at intervals, a plurality of rows are arranged along the length direction of the water injection pipe, the distance between every two adjacent water injection holes is 5-10mm, the distance between every two adjacent water injection holes is 10-15mm, and the diameter of each water injection hole is 1 mm.
4. The non-drainage sinking construction method of the open caisson according to claim 1, wherein: the step S1 of injecting water in sections is inserting a grouting pipe into the water jet pipe, wherein a sealing plug is sleeved at an end of the grouting pipe inserted into the water jet pipe at intervals, the sealing plug is sealed in the water jet pipe in a sliding manner, and high-pressure water is sprayed out from a designated area of the water jet pipe through a grout outlet on the grouting pipe.
5. The non-drainage sinking construction method of the open caisson according to claim 1, wherein: the caisson water level is maintained above the groundwater level in step S2.
6. The non-drainage sinking construction method of the open caisson according to claim 1, wherein: in step S2, the central scouring depth of the bottom of the open caisson is not more than 1.0m, and the width of the soil ridge of the edge leg around the open caisson is 80 cm.
7. The non-drainage sinking construction method of the open caisson according to claim 1, wherein: and in the step S3, when the open caisson sinks for 1-2m, high-pressure water is sprayed to the soil body in the newly sinking area of the open caisson through the water injection pipe in a sectional water injection mode.
8. The non-drainage sinking construction method of the open caisson according to claim 4, wherein: and in the step S4, soil is grouted by using the grouting pipe.
9. The method for constructing the open caisson by non-drainage sinking according to claim 8, wherein: the grouting slurry is cement-water glass double slurry.
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CN202010950466.3A CN112252349A (en) | 2020-09-11 | 2020-09-11 | Sinking construction method without drainage for open caisson |
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CN202010950466.3A CN112252349A (en) | 2020-09-11 | 2020-09-11 | Sinking construction method without drainage for open caisson |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113756351A (en) * | 2021-09-23 | 2021-12-07 | 黄河建工集团有限公司 | Construction method for sinking of non-drainage open caisson |
CN113846664A (en) * | 2021-08-05 | 2021-12-28 | 上海市基础工程集团有限公司 | Continuous soil-taking and sinking machine for non-drainage open caisson |
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CN105386453A (en) * | 2015-10-16 | 2016-03-09 | 上海市基础工程集团有限公司 | Grouting process for preventing secondary settlement of open caisson |
CN107023026A (en) * | 2017-06-02 | 2017-08-08 | 中国矿业大学 | A kind of sealing bottom type caisson wall and construction method |
CN110565670A (en) * | 2019-08-09 | 2019-12-13 | 中铁八局集团有限公司 | sinking construction system without water drainage for open caisson and construction method thereof |
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KR20070058787A (en) * | 2005-12-05 | 2007-06-11 | 주식회사 우지스건설 | Well foundation water-proofing grouting apparatus and its well foundation construction method |
CN103088837A (en) * | 2013-02-27 | 2013-05-08 | 上海市基础工程有限公司 | Mud anti-drag sink-assisting device in open caisson sinking construction |
CN105386452A (en) * | 2015-10-16 | 2016-03-09 | 上海市基础工程集团有限公司 | Construction method for assisting in sinking of open caisson through high-pressure water |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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CN113846664A (en) * | 2021-08-05 | 2021-12-28 | 上海市基础工程集团有限公司 | Continuous soil-taking and sinking machine for non-drainage open caisson |
CN113846664B (en) * | 2021-08-05 | 2023-03-10 | 上海市基础工程集团有限公司 | Continuous soil-taking and sinking machine for non-drainage open caisson |
CN113756351A (en) * | 2021-09-23 | 2021-12-07 | 黄河建工集团有限公司 | Construction method for sinking of non-drainage open caisson |
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