Picket radical
Phyletic and various, construction craft difference is big, variation of together with layer is complex, may make picket body appears in construction process shrink mud of diameter, enlarge diameter, clip, separation, break the blemish such as picket, of course after construction by mechanical excavate, collision also can cause defect of body of shallow ministry picket. The existence of picket body blemish is met the regular job character of change radical picket, produce potential risk to the foundation thereby. We summed up a project today in the common problem of picket radical, look together.
Picket radical
Detect
When what circumstance should undertake test and verify and expand detect?
(1) when low meet an emergency detects, to embedding cliff picket, signal of reflex of picket bottom time domain is onefold reflex wave and attack signal to be the same as with hammer to when; Actual measurement signal is mixed, without the rule, cannot have accurate opinion to its; Picket body is sectional gradual change or changeful, and the hour of concrete perfusion picket with metabolic bigger range uses Jing Zaifa or get core law test and verify.
(2) when tall meet an emergency detects, picket body is put in blemish, cannot decide the vertical stroke of picket to bear the weight of force; Or picket body blemish bears the weight of to the level force is influential; Click pile penetration big, picket bottom is the same as to reflection puissant and reflection peak is wider, reflex of side obstruction wave, upright obstruction wave is weak, namely weaveform shows vertical stroke to bear the weight of when character reports with reconnaissance medium geological condition is not accorded with apparently, can use Jing Zaifa farther test and verify;
(3) bottom of stake of the stake that embed cliff is the same as to reflection intense, and without apparent end after time 2L/C obstruction is reflexed, can use test of nucleus of the law that get core.
(4) blemish of picket body shallow ministry can use excavate test and verify.
(5) the prefab picket of picket body or contact existence cranny can use test and verify of law of tall meet an emergency.
(6) odd Kong Zuanxin detects when discovering problem of quality of picket body concrete, appropriate is in same base picket increases bore test and verify.
(7) the picket that integrality category cannot make clear in detecting to law of low meet an emergency or Ⅲ kind picket, can use the appropriate methodological test and verify such as law of the Jing Zaifa, law that get core, tall meet an emergency, excavate to detect according to actual condition.
(8) bear the weight of when single stake when sufficient design of force or dissatisfaction of result of sampling observation of the law that get core asks, should analyse a reason, and classics sampling observation expands after affirming.
(9) should use the Ⅲ that integrality of body of picket of sampling observation of way of transmission of wave of harmony of law of law of low meet an emergency, tall meet an emergency discovers, Ⅳ kind picket the sum is more than sampling observation picket to count 20% when, appropriate is used detect formerly method (way of sound wave transmission can convert the law that get core) , in did not continue to enlarge sampling observation in check picket.
Base does picket detect should the report contain those content?
Detect the report should contain the following content:
(1) entrust square name, project name, place, construction, reconnaissance, design, inspect manage and construction unit, foundation, structural type, number of plies, design a requirement, detect purpose, detect according to, detect amount, detect date; (2) geological condition description; (3) the picket sign of picket getting check, picket record with relevant construction; (4) detect method, testing instrument equipment, detect the process is narrated; (5) of picket getting check detect data, actual measurement and computation analyse curve, form and collect result; (6) with detect content detects accordingly conclusion. Project picket bears the weight of force detects the evaluation of the result, should give out of every picket getting check bear the weight of force detects value, give out accordingly the single stake that same condition leaves unit project bears the weight of the conclusion that whether force eigenvalue satisfies a design to ask.
Does the single stake standard that same condition issues unit project bear the weight of what regulation should force eigenvalue accord with surely really?
(1) bear the weight of when the level when force is controlled by picket body strength, take a level value of critical load statistic bears the weight of for single stake water force eigenvalue.
(2) suffer effect of long-term level load when picket and when shape does not allow craze, take a level critical load statistic is worth 0.8 times bear the weight of as single stake level force eigenvalue.
(3) bear the weight of when the level when force allows displacement to control by the level that designs a requirement, desirable the horizontal load that designs the level of the requirement to allow displacement correspondence bears the weight of as single stake level force eigenvalue, but should satisfy concerned standard to refuse the demand that cracks a design.
Construction
Problem
Leakage oar
Phenomenon: Leakage oar weighs Guan Chong on hydraulics, common phenomenon is to protect the surface outside the canister to risk a bleb or muddy water, occurrence above phenomenon means leakage oar to already happened.
Processing technique: Add cement or vibration to protect a canister to sink. Protect a canister to sink not to exceed 1m, if protect a canister to sink,exceed 1m, or protect a canister to sink suddenly, should halt construction.
Collapse aperture
Phenomenon: Cuttings pick-up amount is unusual increase, borer bear is increased suddenly or protect face of the slop inside the canister to have the appearance such as a large number of close bleb generation suddenly.
Processing technique: Appear collapse Kong Ying stops to be gotten into instantly, carry broach, prevent broach to be buried to set. Because collapse after Kong Zhi, the annulus arch action of system of land be destructived disappears suddenly, hole wall is entered extremely flabby decided position. Right now backfill earth quiet place is the most efficient way.
Rise of basket of reinforcing steel bar
Phenomenon: When transfer to a lower level of basket of reinforcing steel bar cannot reach the designated position smoothly, it is the commonnest problem in construction of picket of perfusion of long helix bore, sometimes because basket of reinforcing steel bar is too long, to the half card is below inside aperture, fall to be not carried again already, be forced to cut off from eat dishes without rice or wine.
Processing technique:
(1) hit concrete not to reach the designated position, midway is carried had gotten fast or too slow, the time that dominates big concrete strictly and its plentiful coefficient ensure coagulation plentiful coefficient is asking limits;
(2) too big or slump is too small, detect whether does concrete slump satisfy a requirement, slump is too big, produce phenomenon of secrete water, separation easily, appear inside short time thick aggregate sinks, grout float above. Make obstruction of be issued to lower levels of basket of reinforcing steel bar increases, bring about steel basket to cannot reach the designated position; Slump is too small, still can increase below basket difficulty, because this is in construction process,must control slump strictly in 18 ～ 22cm;
(3) quality of basket of reinforcing steel bar too poor or the design is unreasonable, press blueprint strictly the norms of basket of reinforcing steel bar, do not appear dragon muscle passes big question,
(4) chosen oscillatory hammer power wants appropriate. Transfer to a lower level of basket of reinforcing steel bar arrives be apart from orifice when 1 ～ 2m, want to rely on next to design elevation sending to carry the oscillatory weight that protects a canister, 400mm of general picket diameter, stake grows not to exceed the stake of 10m, the oscillatory hammer into shape that chooses 1.8kW can satisfy a requirement; 600mm picket diameter, stake grows those who be less than 15m base picket, the oscillatory hammer into shape that chooses 2.2kW is advisable;
(5) whether does diameter of examination broach, drill pipe satisfy a requirement. If discover broach, wear away serious, should fill in time solder, outer predestined relationship sets alloy piece, ensure bore diameter and covering layer satisfy a requirement. Make there is enough space between basket of reinforcing steel bar and hole wall, make basket of reinforcing steel bar reachs the designated position smoothly.
Slant aperture
Phenomenon: Often also exist in process of punching picket construction slant aperture problem. Encounter in punching have bigger Gu stone or probe rock (brae cliff face) , have boundary of declining soft hard layer cliff face tilts when rush or rushing in the arenaceous pebble layer of wide gap of bead diameter magnitude, reaming is bigger place peen swings when deflection one party, base of punching picket engine did not find a place for level or when producing inhomogenous settlement, displacement, happen all likely slant aperture.
Processing technique:
(1) when installing punching picket machine, should make level of chassis, base, the Ka Konghe of the wire rope that flange, fixed peen slips again since protects canister center 3 person should be on an upend line, often check corrective;
(2) when should discovering peen concussion is flabby (the left and right sides swings) should stop to pound, whether is examining to happen slant aperture, if happen,slant the processing when Kong Ji;
(3) have when discovery slant Kong Shixian is found out slant Kong Yuan slants because of reaching the size of aperture, if because peen pounds Gu stone or probe stone,be (brae cliff face) when want seasonable to stone of the backfill inside aperture, backfill arrives when 1m of altitude cliff face in concussion.
Wintersweet aperture (or crossed aperture)
Phenomenon: When punching picket is pounded, to become aperture out of round.
Processing technique:
(1) the slop that chooses proper viscosity and opposite density, timely draw out broken bits;
(2) when using low stroke, every concussion is changed one paragraph with a few taller stroke concussion, pound nap aperture look alternately;
(3) after occurrence wintersweet aperture, usable piece, bore of backfill of pebble mixture clay, pound afresh.
Quality
Problem
Common quality problem
(1) measure the mistake appears in putting a line, this kind of wrong misunderstanding makes whole structure occurrence mistake perhaps makes picket radical appears bigger error.
(2) single stake bears the weight of force does not satisfy a building picket radical designs a standard.
(3) picket body has tilted big.
(4) the connect of prefab picket happens to leave.
(5) what cause in the process of fill picket the accident that snap stake.
(6) picket discovers in checking and accept a process had had big error.
(7) occurrence clip mud, separation and intensity do not amount to the picket system that because the quality of concrete perhaps is operated,causes the problem such as mark.
(8) elevation is insufficient.
Handle measure
Fill heavy law
When deepness of prefab picket be buried is insufficient, or infiltrate picket because when earthy system apophysis will carry on picket, all can use this method.
Law of filling picket of filling picket law
Be in namely the opinion jointly with manage of design, inspect and owner, the filling picket plan that issues according to designing an unit undertakes filling hitting, but this kind of method invests big, time limit for a project to grow, be approbated very hard jointly by each.
By-carriage combines a magic art
Use articulatory connective means to infiltrate picket when the foundation is medium, if picket style quality does not amount to mark, so in the process that having sinking, make likely even node come away, at this moment to picket base the means that processing can use by-carriage to be united in wedlock.
To having the stake of doubtful point, ought to undertake answer dozen, your this picket sinks, the picket connection that this can make be out of line supports again close, your connect has vertical stroke to bear the weight of force; Can have filling stake, fill appropriately into a few complete picket, make foundation not only OK and contented bear the weight of power demand, still can increase the seismic load that builds a base at the same time.
Law of correct an error
If discover in pile process picket body appears,tilt and stake does not grow, and in good condition did not rupture, or as a result of base the excavate of hole and the picket body that bring about appears tilt but picket body remains the same complete, can undertake local excavate to picket body, use jack to undertake correct an error to picket body next.
Bear the stage expands
(1) be like picket appeared bigger error, so original bear the normative sex requirement that the stage designs dimension to cannot satisfy construction, can pass so right bear the kind that the stage is the amplification with proper area is right picket deviation undertakes corrective.
(2) picket ground is common action. Be like what single stake cannot achieve a design to bear the weight of power demand, undertake with respect to need bear the amplification of the stage is handled, and even will natural base the shoulders jointly upside load that is the same as picket considers inside.
(3) picket matrix measures an issue. Appear easily in construction uneven picket radical quality, cause to because picket matrix measures an issue,avoid later period bear tablecloth bureau cloud sedimentations and to raise architectural aseismatic ability, can use integral type stake base bear stage, raise fundamental whole sex thereby.
Compound foundation law this law
(1) it is to use picket land the principle of joint action, make proper processing to foundation, raise foundation to bear the weight of force, more effective partake the load of picket radical. Commonly used method has the following kinds.
(2) bear the foundation that exchange land is become below the stage. In picket base bear before platform construction, dig the territory that divides certain deepness, change arenaceous stone to fill a layer statified tamper is filled mix in artificial foundation again next the construction on picket radical bear stage.
(3) cement earth stake is added between picket. Bear the weight of when picket when force short of designs a requirement, can use cement of dry in the earth between picket in season to form the method of cement earth picket, form compound foundation basis.
Modification picket or law of heavy picket parameter
(1) change picket. Be like prefab prestressing force of square picket instead is in charge of picket to wait.
(2) deepness of change picket be buried. For example prefab picket encounters thicker close-grained pink into the process in be linked together arenaceous or powdery earth layer, it is difficult that occurrence picket sinks, produce picket accident even, can use right now shorten picket is long, increase picket amount, take close-grained powdery arenaceous layer (expand earthy layer) as the layer that hold power.
(3) change picket. If be encountered in heavy picket hard, not big underground fraise, make picket generation tilts, when rupturing even, can use change stake sink afresh picket.
(4) become heavy picket equipment. When picket sinks to design a requirement into deepness short of, can use big tonnage pile frame, use heavy weight low attack law heavy picket.
