CN103046569B - Construction method for large-sized open caisson to penetrate through cement interlayer in deepwater - Google Patents

Abstract

The invention discloses a construction method for a large-sized open caisson to penetrate through a cement interlayer in deepwater and relates to the field of bridge foundation construction. The method includes the steps: using an iron sheet to make a cylindrical shell, arranging an energy gathering shield on the inner bottom of the shell, filling water-gel explosive in a space between the shell and the energy gathering shield, inserting detonators, and covering a sealing cover; and allowing blasting personnel to transport an energy gathering blaster to an open caisson hole platform, slowly descending the energy gathering blaster by the aid of a lifting rope, leading a nonel along the lifting rope to the top face of the open caisson until the energy gathering blaster is stably placed on the top face of a gravel cement interlayer needed to be blasted underwater, manually detonating the energy gathering blaster to complete blasting operations, and cleaning scrap cement layer blocks out of the open caisson hole through an air suction dredger to enable the open caisson to sink smoothly. Using the deepwater attachment blasting method for breaking the gravel cement interlayer is fine in blasting effect, the open caisson can pass through the cement interlayer safely and smoothly, and sinking construction progress of the open caisson is guaranteed.

Description

The construction method that the medium-and-large-sized open caisson of deep water passes through cementing interlayer

Technical field

The present invention relates to bridge foundation construction field, particularly relate to the construction method that the medium-and-large-sized open caisson of a kind of deep water passes through cementing interlayer.

Background technology

Open caisson foundation is with the underground structure of drop shaft sinking construction and a kind of pattern of deep foundation.The general works that is first made into a pit shaft shape on earth's surface, i.e. open caisson then passes through constantly to cut the earth in well under the going along with sb. to guard him of the borehole wall, and open caisson is sunk gradually under Gravitative Loads, reaches after predetermined design absolute altitude, then carries out back cover, constructs internal construction.Open caisson foundation is widely used in the construction basis of bridge, chimney, water tower, also can be used as the active well of the deep-well structure such as pump house, oil cellar, pond vertical shaft and shield structure or push pipe, technical safer reliable, shoveling amount is few, impact on adjacent structure is smaller, open caisson foundation is embedding darker, and good stability can support larger load.The advantages such as open caisson foundation is large with its rigidity, good stability, quick construction are more and more applied in Longspan Bridge basis.

Well sinking adopts airlift suction dredger suck sediment subsidence, punching to grab the construction method such as sinking, strand suction sinking conventionally, but for the open caisson in specific condition and special sandwich, such as: large-scale well-sinking sinks in the higher cementing interlayer of profundal zone intensity, all there is larger difficulty in above-mentioned construction method: cementing interlayer intensity is high, be difficult to fragmentation, punching is grabbed and is needed corresponding crane gear, strand to inhale equipment construction to be limited in scope etc.

Describe as example to close good fortune railway Tongling Yangtze Bridge below.

1, the geological conditions of design:

Shown in Figure 1, the long limit of bottom plane of open caisson direction across bridge is of a size of 62.4m, is highly 68m, and bottom is the high steel open caisson of 50m, and top is 18m high concrete open caisson, and open caisson top mark height is+6.0m that end absolute altitude is-62.0m.Shown in Figure 2, the planar dimension of open caisson interlude is 62mx38m, and open caisson is divided into 12 wellholes by the borehole wall and separation, and wellhole is according to from north orientation south, and from west, serial number is eastwards N1～N4, M1～M4, S1～S4.Shown in Figure 3, open caisson along bridge to bottom plane minor face be of a size of 38.4m.Shown in Figure 4, open caisson top planar dimension is 64mx40m.

The open caisson region from top to bottom engineering properties brief introduction of each soil layer is as follows:

Flour sand: lark, saturated, loose shape, composition taking quartz, feldspar is as main, a small amount of mica, matter is purer.

Silty clay: lark, grey, hard plastic shape, matter inequality, folder silt, flour sand thin layer, the top root system of plant of mixing; Mainly be layered distribution in inaction bank covering layer middle and upper part.

Thin circle gravel soil: grey, lark, saturated, closely knit shape, containing 50～75% ovum cobbles; Cobble composition is taking quartz sandstone as main, and degree of rounding is medium; Powder sand filling is main, and a small amount of medium coarse sand, cohesive soil filling, be layered distribution.

Table 1, each soil layer mechanical index statistical form

According to above-mentioned geological conditions, adopt that mobility is strong, better economy, the less demanding airlift suction dredger of crane gear (being aided with jetting) carried out to suck sediment subsidence.

2, the geology of finding in open caisson construction changes:

In the geologic information of design, there is no cementing interlayer, but the mud extraction situation during according to suction mud and the lump feature of taking out in dredging tube, and water detection event under Divers, judge and have cementing interlayer in the part wellhole of open caisson, approximately 1～2m of cementing thickness of interlayer, compressive strength 20～25Mpa.

The detection event of diving under water in cementing interlayer and suction mud situation are as follows:

(1) be probably positioned at-45.2m of cementing interlayer place in N1 wellhole, cementing sandwiching surface is ramped shaped, and internal partition wall corner is higher, utilizes respectively with suction dredge is inhaled mud, and mud extraction effect is all very poor, and when loop wheel machine pine hook, at the bottom of suction dredge, mouth has obviously to middle sliding phenomenon, and cementing interlayer intensity is higher, utilizes suction dredge to smash downwards, and cementing interlayer does not destroy.

(2) be probably positioned at-44.4m of cementing interlayer place in M1 wellhole, cementing sandwiching surface is down infundibulate, and in storehouse, middle landform is high, at the bottom of surrounding, when loop wheel machine pine hook, at the bottom of suction dredge, mouth has obvious sliding phenomenon, utilizes suction dredge to smash downwards, and local broken rear mud extraction effect is better, main containing silt and cobble in mud, be black, while inhaling mud to-46.8m, mud extraction poor effect.

(3) in M2, M3 wellhole, cementing interlayer is thinner, utilizes suction dredge to smash to pieces, is scattered and has a large amount of cementing interlayer fragments, mud extraction poor effect in storehouse.

(4) be probably positioned at approximately-45m of cementing interlayer place in S1 wellhole, the cementing sandwiching surface discrepancy in elevation is little, mud extraction effect is poor, there is once in a while boulder to go out with slurry, soil contains the cementing interlayer block of large particle diameter and cobble herein, dredging tube is repeatedly blocked, and is cementing interlayer block or cobble and is stuck in mouth at the bottom of suction dredge.

(5) be probably positioned at-44.8m of cementing interlayer place in S2 wellhole, cementing sandwiching surface is ramped shaped, and the gradient is steeper, high in the south and low in the north, and under Divers, water is felt and is found that there is column dell, high 1.3 meters of left and right, hole wall is very steep, and geology is more closely knit.

(6) be probably positioned at-44.2m of cementing interlayer place in S3 wellhole, cementing sandwiching surface is infundibulate, middle low, and under Divers, water is felt a large amount of cementing interlayer fragments that are scattered in discovery storehouse, and particle diameter is larger.

Because cementing interlayer intensity is high, thickness is larger, is difficult to fragmentation, the suction mud effect extreme difference of suction dredge, well sinking is obstructed, and causes subsidence velocity very slow, has a strong impact on well sinking progress.

Summary of the invention

The object of the invention is the deficiency in order to overcome above-mentioned background technology, a kind of deep water construction method that medium-and-large-sized open caisson passes through cementing interlayer is provided, adopt the cementing interlayer of deep water veneer blasting method broken pebble, demolition effect is better, make open caisson safety smoothly by cementing interlayer, ensure the construction speed of well sinking.

The construction method that the medium-and-large-sized open caisson of deep water provided by the invention passes through cementing interlayer, comprises the following steps:

S1, making CUMULATIVE BLASTING device: adopt iron sheet to make the closed cylindrical shell of CUMULATIVE BLASTING device, conical energy gathering cap is arranged in to the inner bottom surface of shell, aqueous gels are packed between shell and energy gathering cap, then insert detonator, cover again seal cover, utilize the medicine containing opening of O type circle can upper surface, utilize resin glue to seal the eyelet of the seal cover that inserts detonator, detonator is connected with plastic detonating tube;

S2, lay CUMULATIVE BLASTING device: the powder charge of CUMULATIVE BLASTING device, sealed after, explosion personnel are properly transported to CUMULATIVE BLASTING device on open caisson wellhole platform, to hang rope system is connected on CUMULATIVE BLASTING device iron wire handle, utilization hangs rope and slowly transfers CUMULATIVE BLASTING device, detonator causes open caisson end face along hanging rope, until CUMULATIVE BLASTING device is steadily placed in the end face that needs the cementing interlayer of the cobble of explosion under water, in the process hanging, keep CUMULATIVE BLASTING device not contact with open caisson wellhole downwards, keep detonator smooth-going;

S3, manually ignite CUMULATIVE BLASTING device: after CUMULATIVE BLASTING device is in place, explosion personnel from platform to open caisson end face, all non-bursting work personnel evacuate to safety area, suction dredge stops inhaling mud, and dredging tube is placed on one jiao of wellhole, and properly temporary fixed with wire rope, explosion commander blows a whistle and confirms after everything in readiness, explosion personnel utilize initiator to excite magnetoelectricity detonator, ignite CUMULATIVE BLASTING device, complete bursting work;

S4, the cleaning of cementing interlayer block: by airlift suction dredger, the cementing interlayer block of scraping is cleaned out to open caisson wellhole, open caisson is sunk smoothly.

In technique scheme, the thickness of iron sheet described in step S1 is 1.2～1.8mm.

In technique scheme, the thickness of iron sheet described in step S1 is 1.6mm.

In technique scheme, aqueous gels described in step S1 adopt water-fast aqueous gels under the water pressure of 0.5Mpa.

In technique scheme, in step S1, described aqueous gels are to cone or hemispherical.

In technique scheme, detonator described in step S1 adopts the detonator that can not naturally detonate under the pressure of 0.5Mpa.

In technique scheme, the design formulas of described CUMULATIVE BLASTING device size design is as follows:

$m=\mathrm{\ρ}.V=\mathrm{\ρ}(\frac{\mathrm{\π}{D}^2}{4}H-\frac{\mathrm{\π}{D}^2}{12}h),$

Wherein: m is aqueous gels quality, ρ is aqueous gels density; V is cumulative cartridge bag volume; D is cumulative cartridge bag internal diameter; H is cumulative cartridge bag height; H is energy gathering cap height.

In technique scheme, D:H=2:3, h=0.5D.

Compared with prior art, advantage of the present invention is as follows:

(1) the present invention adopts the cementing interlayer of deep water veneer blasting method broken pebble, select and can resist the quick-fried detonator of leading of 0.5Mpa water pressure and aqueous gels as Blasting in deep water equipment, and adopt the special CUMULATIVE BLASTING device of making in deep water, to carry out little dose explosion, demolition effect is better, make open caisson safety smoothly by cementing interlayer, ensure the construction speed of well sinking, the defect that adopts drilling and blasting method in deep water be can overcome, the suction mud poor effect of the cementing interlayer of cobble in caisson sinking construction process, the problem that well sinking is obstructed solved.

(2) due to the depth of water explosion in 50m left and right, explosive quantity is little, and bursting work sealing wellhole in carry out, near environment without impact, without consider explosion on navigating, the impact of building, also do not consider the impact of slungshot on ground or water surface the above persons.

(3) equipment that the present invention uses is simple, processing ease, maneuverability, strong adaptability.

Brief description of the drawings

Fig. 1 is the structural representation of the positive facade of open caisson direction across bridge.

Fig. 2 is the floor map of open caisson interlude.

Fig. 3 be open caisson along bridge the structural representation to side elevation.

Fig. 4 is the structural representation of open caisson top plane.

Fig. 5 is the structural representation of CUMULATIVE BLASTING device in the embodiment of the present invention.

In figure: 1-shell, 2-energy gathering cap, 3-aqueous gels, 4-detonator, 5-detonator, 6-seal cover.

Detailed description of the invention

Below in conjunction with drawings and the specific embodiments, the present invention is described in further detail.

The embodiment of the present invention adopts the special CUMULATIVE BLASTING device of making in deep water, to carry out little dose explosion.Shown in Figure 5, CUMULATIVE BLASTING device comprises shell 1, energy gathering cap 2, aqueous gels 3, detonator 4, detonator 5, seal cover 6, shell 1 is cylindrical, employing iron sheet is made, it is conical that energy gathering cap 2 is, be positioned at the inner bottom surface of shell 1, between shell 1 and energy gathering cap 2, be filled with aqueous gels 3, the iron sheet center of shell 1 upper surface has medicine containing opening, medicine containing opening place is provided with the seal cover 6 for sealing medicine containing opening, the center of seal cover 6 has eyelet, and detonator 5 is connected with detonator 4, and detonator 4 inserts the eyelet that is positioned at seal cover 6 centers.

The embodiment of the present invention provides a kind of deep water construction method that medium-and-large-sized open caisson passes through cementing interlayer, comprises the following steps:

S1, making CUMULATIVE BLASTING device:

The main equipment of preparing has: aqueous gels, nonpriming material detonator, composite high-strength plastic detonating tube, CUMULATIVE BLASTING device, initiator, hang rope, iron wire, resin glue, Walkie talkie, Blasting in deep water for carrying out explosion under approximately 50 meters of conditions of the depth of water, common explosive cannot operation, therefore select and can resist the quick-fried detonator of leading of 0.5Mpa water pressure and aqueous gels, and the special CUMULATIVE BLASTING device of making of employing, meet anti-deep-water pressure requirement, reach demolition effect.

Employing thickness is the closed cylindrical shell 1 that the iron sheet of 1.2～1.8mm (preferably 1.6mm) is made CUMULATIVE BLASTING device, plays the object that cartridge bag is shaped and seals explosive; The inner bottom surface that conical energy gathering cap 2 is arranged in to shell 1, utilizes the cumulative action of CUMULATIVE BLASTING device, improves the crushing effect of blast.

For preventing that explosion from producing and destroying caisson structure, be generally no more than 2kg in the dosage of open caisson well downhole explosion, accordingly the size of dose design CUMULATIVE BLASTING device.

The design formulas of CUMULATIVE BLASTING device size design is as follows:

$m=\mathrm{\ρ}.V=\mathrm{\ρ}(\frac{\mathrm{\π}{D}^2}{4}H-\frac{\mathrm{\π}{D}^2}{12}h)$

Wherein: m is aqueous gels quality; ρ is aqueous gels density, is taken as 1.15g/cm ³; V is cumulative cartridge bag volume; D is cumulative cartridge bag internal diameter; H is cumulative cartridge bag height; H is energy gathering cap height; D, H, h determine according to dosage, D:H=2:3, h=0.5D.

Water-fast aqueous gels 3 under the water pressure of 0.5Mpa are packed between shell 1 and energy gathering cap 2, and aqueous gels 3 are cone or hemispherical; Then be inserted in the detonator 4 that can not naturally detonate under the pressure of 0.5Mpa, prevent from naturally detonating under deep-water pressure, ensure can detonate smoothly under Artificial Control simultaneously; Cover seal cover 6 again, utilize the medicine containing opening of O type circle can 1 upper surface, utilize resin glue to seal the eyelet of the seal cover 6 that inserts detonator 4, detonator 4 is connected with plastic detonating tube 5.

S2, lay CUMULATIVE BLASTING device:

The powder charge of CUMULATIVE BLASTING device, sealed after, explosion personnel are properly transported to CUMULATIVE BLASTING device on open caisson wellhole platform, to hang rope system is connected on CUMULATIVE BLASTING device iron wire handle, utilization hangs rope and slowly transfers CUMULATIVE BLASTING device, detonator causes open caisson end face along hanging rope, until CUMULATIVE BLASTING device is steadily placed in the end face that needs the cementing interlayer of the cobble of explosion under water, require energy gathering cap steadily to place, must not turn on one's side, topple over phenomenon.Shock wave by blast smashes cementing interlayer, does not need underwater drilling that explosive is installed.In the process hanging, to keep CUMULATIVE BLASTING device not contact with open caisson wellhole downwards, keep detonator smooth-going, prevent from tearing detonator, guarantee not affect the follow-up operation of detonating.

S3, manually ignite CUMULATIVE BLASTING device:

After CUMULATIVE BLASTING device is in place, explosion personnel are to open caisson end face from platform, and all non-bursting work personnel such as site operation personnel evacuate to safety area, and suction dredge stops inhaling mud, and dredging tube is placed on one jiao of wellhole, and properly temporary fixed with wire rope.Explosion commander blows a whistle and confirms that after everything in readiness, explosion personnel utilize initiator to excite magnetoelectricity detonator, ignites CUMULATIVE BLASTING device, completes bursting work.

S4, the cleaning of cementing interlayer block:

By airlift suction dredger, the cementing interlayer block of scraping is cleaned out to open caisson wellhole, open caisson is sunk smoothly.

Obviously, those skilled in the art can carry out various changes and modification and not depart from the spirit and scope of the present invention the present invention, if these amendments of the present invention and within modification belongs to the scope of the claims in the present invention and equivalent technologies thereof, the present invention comprises these changes and modification interior.

The content not being described in detail in this manual belongs to the known prior art of professional and technical personnel in the field.

Claims (8)

1. the construction method that the medium-and-large-sized open caisson of deep water passes through cementing interlayer, is characterized in that, comprises the following steps:

S1, making CUMULATIVE BLASTING device: adopt iron sheet to make the closed cylindrical shell (1) of CUMULATIVE BLASTING device, conical energy gathering cap (2) is arranged in to the inner bottom surface of shell (1), aqueous gels (3) are packed between shell (1) and energy gathering cap (2), then insert detonator (4), cover again seal cover (6), utilize the medicine containing opening of O type circle can (1) upper surface, utilize resin glue to seal the eyelet of the seal cover (6) that inserts detonator (4), detonator (4) is connected with plastic detonating tube (5);

S2, lay CUMULATIVE BLASTING device: the powder charge of CUMULATIVE BLASTING device, sealed after, explosion personnel are properly transported to CUMULATIVE BLASTING device on open caisson wellhole platform, to hang rope system is connected on CUMULATIVE BLASTING device iron wire handle, utilization hangs rope and slowly transfers CUMULATIVE BLASTING device, detonator causes open caisson end face along hanging rope, until CUMULATIVE BLASTING device is steadily placed in the end face that needs the cementing interlayer of the cobble of explosion under water, in the process hanging, keep CUMULATIVE BLASTING device not contact with open caisson wellhole downwards, keep detonator smooth-going;

S3, manually ignite CUMULATIVE BLASTING device: after CUMULATIVE BLASTING device is in place, explosion personnel from platform to open caisson end face, all non-bursting work personnel evacuate to safety area, suction dredge stops inhaling mud, and dredging tube is placed on one jiao of wellhole, and properly temporary fixed with wire rope, explosion commander blows a whistle and confirms after everything in readiness, explosion personnel utilize initiator to excite magnetoelectricity detonator, ignite CUMULATIVE BLASTING device, complete bursting work;

S4, the cleaning of cementing interlayer block: by airlift suction dredger, the cementing interlayer block of scraping is cleaned out to open caisson wellhole, open caisson is sunk smoothly.

2. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 1 passes through cementing interlayer, is characterized in that: the thickness of iron sheet described in step S1 is 1.2～1.8mm.

3. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 2 passes through cementing interlayer, is characterized in that: the thickness of iron sheet described in step S1 is 1.6mm.

4. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 1 passes through cementing interlayer, is characterized in that: aqueous gels described in step S1 (3) adopt water-fast aqueous gels under the water pressure of 0.5Mpa.

5. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 1 passes through cementing interlayer, is characterized in that: in step S1, described aqueous gels (3) are to cone or hemispherical.

6. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 1 passes through cementing interlayer, is characterized in that: detonator described in step S1 (4) adopts the detonator that can not naturally detonate under the pressure of 0.5Mpa.

7. the construction method that the medium-and-large-sized open caisson of the deep water as described in any one in claim 1 to 6 passes through cementing interlayer, is characterized in that: the design formulas of described CUMULATIVE BLASTING device size design is as follows:

$m=\mathrm{\ρ}.V=\mathrm{\ρ}(\frac{\mathrm{\π}{D}^2}{4}H-\frac{\mathrm{\π}{D}^2}{12}h),$

Wherein: m is aqueous gels quality, ρ is aqueous gels density; V is cumulative cartridge bag volume; D is cumulative cartridge bag internal diameter; H is cumulative cartridge bag height; H is energy gathering cap height.

8. the construction method that the medium-and-large-sized open caisson of deep water as claimed in claim 7 passes through cementing interlayer, is characterized in that: D:H=2:3, h=0.5D.