CN101353894B

CN101353894B - Filling pile construction pore-creating method of pervious ultra-deep loose backfill two-piece stone zone

Info

Publication number: CN101353894B
Application number: CN2008101190883A
Authority: CN
Inventors: 金传宏; 杨爱国; 周飞
Original assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Current assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Priority date: 2008-08-28
Filing date: 2008-08-28
Publication date: 2010-06-09
Anticipated expiration: 2028-08-28
Also published as: CN101353894A

Abstract

The invention discloses a drilling method for the construction of a cast-in-place pile of a dank ultra-deep loose refilling rubble area, which comprises the following steps: step 1: a slope area of 4m to 6m is arranged in an area right ahead an arranged pile casing to serve as a slurry return flow line, and a slurry pool is dug outside the slope area; step 2: residue is drawn out once every 1 hour to 3 hours during a punching process; step 3: all the drawn-out slurry flows backwards into a drilling hole by utilizing the slope area; step 4: when punching work is carried out, the proportion of the slurry in the hole is increased, thereby being capable of increasing wall retaining capability and reducing hole collapse risk; and step 5: after drilling is carried out to a stable stratum of certain depth, the proportion of the slurry in the hole is gradually reduced; slurry containing the residue is discharged; and the slurry is discharged once every 2 hours to 3 hours. By adopting the method that the slurry flows backwards naturally, the method of the invention changes the traditional mode of slurry circulation, maintains the balance of the slurry, simplifies the construction process and lowers the construction risk.

Description

A kind of filling pile construction pore-creating method of pervious ultra-deep loose backfill two-piece stone zone

Technical field

The present invention relates to a kind of filling pile construction pore-creating method of pervious ultra-deep loose backfill two-piece stone zone.

Background technology

Existing conventional pouring pile hole technology roughly has several:

1, non-soil compaction mode pore-forming: for example do working system brill (digging) pore-forming, mud off brill (digging) pore-forming, a complete set of pipe follow-up retaining wall method brill (digging) pore-forming; Wherein,

Dried working system bores (digging) pore-forming and mud off bores the place construction that (digging) pore-forming is applicable to that engineering geological conditions is good, the basic difficult hole of collapsing that produces;

A complete set of pipe follow-up retaining wall method is bored (digging) drilling construction expense cost height, generally exceeds 1/3 than additive method.

2, part soil compaction mode pore-forming: long spiral press pore-forming, punching pore-forming, boring squeezed hole, preboring pore-forming are squeezed into (static pressure) preformed pile; Wherein,

The long spiral press pore-forming is applicable to the construction of the good place of engineering geological conditions, and basic being difficult for produces the hole of collapsing, and is mainly used in minor diameter (d≤250mm), the intermediate diameters (250mm＜d＜800mm) construction of stake;

The punching pore-forming is applicable to the pore-forming under the various geological conditionss substantially;

The boring squeezed hole is applicable to the place construction that engineering geological conditions is good, and basic being difficult for produces the hole of collapsing, and is mainly used in the major diameter (d 〉=800mm) construction of stake;

The preboring pore-forming is squeezed into (static pressure) preformed pile and is applicable to the construction of the good place of engineering geological conditions, and basic being difficult for produces the hole of collapsing, and is mainly used in minor diameter (d≤250mm), the intermediate diameters (250mm＜d＜800mm) construction of stake.

3, soil compaction mode pore-forming: tube-sinking cast-in-situ pile, immersed tube ram (squeezing) grouting pile, (squeezing into) Static Pressure Precast Piles, the remain silent prestressed concrete pipe pile and the steel pipe pile of remaining silent; Wherein,

Tube-sinking cast-in-situ pile, immersed tube ram (squeezing) grouting pile and are applicable to all kinds of soil layer pore-formings that pile penetration is lower, are mainly used in minor diameter (d≤250mm), intermediate diameters (250mm＜d＜800mm) construction;

(squeezing into) Static Pressure Precast Piles, remain silent prestressed concrete pipe pile and the steel pipe pile of remaining silent are applicable to all kinds of soil layers constructions that pile penetration is lower, are mainly used in minor diameter (d≤250mm), the intermediate diameters (250mm＜d＜800mm) construction of stake;

Preformed pile expense cost is higher than cast-in-situ concrete poured stake, and steel pipe pile expense cost is higher than preformed pile.

Traditional ready-made hole pouring pile construction mud circulation is dual mode nothing but: a kind of is the direct circulation mode, at the bottom of mud injects drilling rod passages such as (or) mud tubes and arrives the hole by slush pump from mud pit, carry boring mud and return out the aperture along boring and flow back to grit chamber, flow back to mud pit circulation in the above described manner again through (boring mud) post precipitation.This mode require the stratum of boring more stable (be difficult for leakage mud, hole wall is difficult for caving in).Another anti-endless form adopts pump suction type usually, and the mud that carries boring mud directly is drawn into the grit chamber at the bottom of the hole by gravel pump, replenishes the mud through (boring mud) post precipitation simultaneously from the aperture.This mode is easy to generate following problem: 1, at the bottom of the hole suction mud time, because it is untimely that aperture mud replenishes, cause in the hole mud level change bigger, cause diminishing fast of hole wall retaining wall pressure everywhere, cause soil body STRESS VARIATION, very easily produce the hole of collapsing for the unsettled stratum of hole wall (as quicksand, not closely knit sand, soil layer etc.), even the accident that causes bury drills, rig to subside to collapse takes place.2, since on the mud that aspirates out and the additional mud property (as viscosity, proportion or the like) have bigger difference, for the unsettled stratum of hole wall, this variation also can bring disadvantageous result to construction.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of filling pile construction pore-creating method of pervious ultra-deep loose backfill two-piece stone zone, can satisfy large diameter pile, filling pile construction pore-creating under special engineering geology (permeable, tidal range location, not closely knit huge thick backfill layer, weak sludge interlayer) condition can be avoided the hole phenomenon of collapsing.

In order to address the above problem, the filling pile construction pore-creating method that the invention provides a kind of pervious ultra-deep loose backfill two-piece stone zone comprises the steps:

Step

1,4～6m is set in the zone, casing dead ahead that places general slope district as the mud return flow line, mud pit is excavated beyond the district again in general slope; Described general slope district is for having the inclined plane at 5～8 degree angles of inclination;

Step 2, in punch process, drew primary slag in per 1～3 hour;

Step 3, the mud of drawing out utilize general slope district all to flow backwards and get back in the boring;

Add the mud balance in the macropore in the time of step 4, punching operation; Can improve retaining capacity like this, reduce the hole risk of collapsing;

Step 5, be drilled into good ground (argillic horizon among the figure) certain depth after, reduce mud balance in the hole gradually, slag inclusion mud of per 2～3 hours rows, to shorten the clear hole time, guarantee mud property index (mud balance＜1.25 that pouring underwater concrete is preceding, sand factor≤8%, viscosity≤28s) adjusted in the code requirement.

Preferably, utilization is drawn the slag tube and is drawn slag in described step 2.

The present invention has following advantage:

1, passes through the method that employing mud flows backwards naturally, changed the pattern of traditional mud circulation, kept the discrepancy balance of mud, simplified construction technology (not needing to utilize gravel pump to carry out the suction of hole bottom slurry), reduced construction risk.

2, the method by adopting mud to flow backwards naturally, in bore meeting special formation (permeable, tidal range location, not closely knit huge thick backfill layer, weak sludge interlayer) process, make mud property keep stable easily, and make hole wall retaining wall pressure keep more stablely, bring disadvantageous result can for the construction on the unsettled stratum of hole wall.

3, adopt this method, simple and easy to do when needs carry out the mud property adjusting, be beneficial to and shorten the clear hole time, thereby reduced the engineering time of whole single hole, increase the construction effect.

Description of drawings

Fig. 1 is embodiment of the invention construction generalized section.

The specific embodiment

As shown in Figure 1, the present invention carries out filling pile construction pore-creating at backfill two-piece stone layer 1, and backfill two-piece stone layer 1 next coming in order are bottom silt layer 2, farinose argillic horizon 3, argillic horizon 4, remain soil layer 5 and severely-weathered rock stratum 6.Filling pile construction pore-creating of the present invention specifically comprises the steps:

Step 1, lay casing 9, lay casing 9 and can adopt that vibration is heavy to be managed at the certain depth (being no less than 1.5 meters) of backfill two-piece stone layer 1, bottom silt layer 2, farinose argillic horizon 3.Utilize rig 7 and drill hammer 8 to carry out the punching construction at backfill two-piece stone layer 1.The district 10, general slope that reserves 4～6m scope in the dead ahead (promptly with relative position, rig 7 installation sites) of the casing 9 that places in advance is back to the passage of boring 12 as mud, general slope district 10 is for having the inclined plane at certain angle of inclination, and this angle of slope is preferably at 5～8 degree.In addition, beyond general slope district 10, excavate mud pit 11 again;

Step 2, in punch process, utilized in per 1～3 hour and draw the slag tube and draw primary slag, the slag of having drawn to be poured into the grit chamber of mud pit 11 UNICOMs (not shown go out) in, the boring mud natural sedimentation, mud replenishes and is back in the mud pit 11, mud pit 11 plays and converges mud, and mud flow backwards naturally by general slope district 10 adds to the effect of holing in 12;

Step 3, the mud (containing boring mud) drawn out flow back in the mud pit 11 through the grit chamber post precipitation, all flow backwards naturally by general slope district 10 then and get back in the boring 12, and mud flow into and holes in 12 by being arranged on casing 9 top openings;

Backflow by mud in the time of step 4, punching operation strengthens the 12 interior mud balances of holing, and can improve retaining capacity like this, reduces the hole risk of collapsing;

Step 5, be drilled into good ground (argillic horizon 4 among the figure) certain depth after, reduce the mud in the former mud pit 11 that is back in the boring 12, thin up mud gradually, to reduce mud balance in the boring 12 gradually, slag inclusion mud of per 2～3 hours rows to shorten the clear hole time, guarantees mud property index (mud balance＜1.25 that pouring underwater concrete is preceding, sand factor≤8%, viscosity≤28s) adjusted in the code requirement.

The present invention has changed the pattern of traditional mud circulation by the method that employing mud flows backwards naturally, has kept the discrepancy balance of mud, has simplified construction technology (not needing to utilize gravel pump to carry out the suction of hole bottom slurry), has reduced construction risk; In addition, the method that adopts mud to flow backwards naturally, in bore meeting special formation (permeable, tidal range location, not closely knit huge thick backfill layer, weak sludge interlayer) process, make mud property keep stable easily, and make hole wall retaining wall pressure keep more stablely, bring disadvantageous result can for the construction on the unsettled stratum of hole wall.

In sum; being preferred embodiment of the present invention only below, is not to be used to limit protection scope of the present invention, therefore; all any modifications of being done within the spirit and principles in the present invention, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. the filling pile construction pore-creating method of a pervious ultra-deep loose backfill two-piece stone zone is characterized in that, comprises the steps:

Step 1,4～6m is set in the zone, casing dead ahead that places general slope district as the mud return flow line, mud pit is excavated beyond the district again in general slope; Described general slope district is for having the inclined plane at 5～8 degree angles of inclination;

Step 2, in punch process, drew primary slag in per 1～3 hour;

Strengthen the mud balance in the boring in the time of step 4, punching operation;

Step 5, be drilled into the good ground certain depth after, reduce mud balance in the boring gradually, slag inclusion mud of per 2～3 hours rows.

2. a kind of method as claimed in claim 1 is characterized in that, utilization is drawn the slag tube and drawn slag in described step 2.