CN2408451Y - Positive placed cylinder post body reverse force static load test oil pressure device - Google Patents

Abstract

The utility model relates to test equipment used for determining the carrying capacity of a pile, which comprises a lower crown plate, a cylinder of outer diameter is less than a test pile and opening is upward, a plunger moving up in the cylinder, a shifting rod and an oil inlet pipe. The oil inlet pipe is positioned on the side surface of the cylinder, and is communicated with the inner cavity of the cylinder. The cylinder and the shifting rod are vertically arranged on the lower crown plate. The utility model has the advantages of safe test, convenient installation, and low fabrication cost, and the oil pipe standard part can be normally connected by the prior art. Due to the fact that a front set type hydraulic jack is used, a plurality of ready-made standard parts can be utilized; the excessive technical reconstruction is not needed to be made, and the cost is low.

Description

Positively fixed type cylinder body pile reaction static test oil gear

The utility model is a kind of test unit that is used for the load-bearing capacity of definite stake.

Pile foundation is widely used in building, bridge, harbour and offshore engineering.Along with the development of high-rise building and the raising of seismic fortification intensity, requirement falls in the stability and the difference that make shallow foundation on the subsoil often can not satisfy (comprising the small pile basis) building, for guaranteeing the big vertically bearing capacity in basis and property and adaptability under the various geologic condition and the whole resistance to capsizing of resisting complicated load, large diameter pile is to become the desirable basic pattern of skyscraper.The test of large diameter pile at present detects, because preloading bothers, also is subjected to the influence of factors such as place, geology sometimes, makes people try hard to avoid and does static test, only does local test sometimes, calculates bearing capacity by the method for empirical data and the common stake of reference.Yet, because it is more to calculate the related factor of bearing capacity, so in actual engineering, the error of the bearing capacity that draws is bigger, have in addition differ several times, form waste and unsafe factor.Sometimes have no alternative but to strengthen safety coefficient and guarantee building safety, make the foundation pile potentiality can not get due performance.

The traditional experiment charger of large diameter pile generally adopts hydraulic jack, and many same model lifting jack of available separate unit formula are in parallel to load, and the loading counterforce device of lifting jack is chosen according to the field experiment condition.Specifically have: 1, anchoring pile counterforce device frame: utilize girder and secondary beam to form reaction frame, this device is passed to anchoring pile with the counter-force (kick) of lifting jack.The counter-force that anchoring pile and reaction beam device can provide should be not less than 1.2～1.5 times that estimate maximum trial load.When adopting engineering piles to make anchoring pile, anchoring pile quantity must not be less than 4, obtains maximum bearing capacity of single pile for making test pile, and 6～8 commonly used, its embedded depth should not made anchoring pile for prefabricated pile less than the test pile degree of depth, note the connection of joint.Make anchoring pile for bored concrete pile, steel reinforcement cage is wanted elongated configuration.Anchoring pile will calculate by the relevant regulations of uplift pile to be determined, in process of the test the amount of pulling out on the anchoring pile is monitored, usually should not be greater than 7～10mm.Before the test girder steel is carried out the strength and stiffness checking computations, and strength checking is carried out in the lacing wire of anchoring pile.Except engineering piles when the anchoring pile, the also way of available earth anchor.

2, the heavy platform counterforce device of heap: the ballast amount must not be less than 1.2 times that estimate the test pile failing load, and ballast should once add before test, and evenly firmly be positioned on the platform.The heavy available steel ingot of heap, concrete block, packed sand or water tank etc.When conduct heap weights such as be packed in bag sand or packeted soil, rubble, in installation process, still need and do technical finesse, in case protruding the collapsing of drum.Except that high tonnage strength and stiffness were calculated, the carrying plane of also tackling preloading checked, in case big non-uniform settling appears in the preloading platform.

3, anchoring pile ballast associating counterforce device: when test maximum load amount surpasses the resistance to plucking ability of anchoring pile, can bear lifting jack jointly by anchoring pile and weight and load counter-force placing or hang certain weight on the anchoring pile and on the crossbeam.When adopting many lifting jack to load, lifting jack answers strictness to carry out physical dimension centering, and with lifting jack synchronous working in parallel, the position up and down of lifting jack need be provided with the pad case of sufficient intensity and rigidity, and makes the test pile center of making a concerted effort to pass through of lifting jack.

The common drawback of above-mentioned various devices be the material that all needs to carry hundreds of or thousands of tons of as the ballast preloading, also need to construct heavy reaction frame.In construction such as road and bridge, be subjected to the restriction of geographical environmental condition big.As be not suitable for test pile of narrow place test pile, harbour, offshore engineering and soft clay area in test pile waterborne, the city etc., because set up the preloading platform or the anchoring pile reaction frame is had any problem.For having one in the skyscraper to the situation of several layers of basement, not only Shi Yan difficulty is bigger, and excavation of foundation pit gets too dark, do not allow exposure too of a specified duration, and construction speed is not allowed yet.

Notification number is that the Chinese patent literature of CN2305667X has been announced a kind of " pile bearing capacity determinator ", form by lower roof plate, top offset sensor and bottom offset sensor, on lower roof plate, be provided with the hydraulic jack of external diameter less than detective pole, the piston of hydraulic jack and lower roof plate offset and be provided with oil inlet pipe on cylinder bodies, the top offset sensor is located on the cylinder body, and the bottom offset sensor is located on the lower roof plate.Be inverted (Open Side Down for cylinder body) because the structure of this device is a cylinder body, oil inlet pipe is contained in cylinder and pushes up, and therefore has following shortcoming: 1, the cylinder top is stressed centrostigma, and pressure is very high, thereby increases sealing difficulty and damage easily; 2, can not utilize the ordinary jack of prior art and ready-made standard component to reconfigure, make installation and make things convenient for inadequately, cost is higher.

The purpose of this utility model provides and does not a kind ofly not only need to carry a large amount of materials as the ballast preloading with construct heavy reaction frame, and seal easy long service life, can utilize the ordinary jack of prior art and ready-made standard component to reconfigure, make pile bearing capacity test unit easy for installation, that cost is low.

Structure of the present utility model is: include lower roof plate, external diameter is less than cylinder body detective pole, that opening makes progress, the piston that can move up in the cylinder body, and displacement bar and oil inlet pipe, oil inlet pipe is communicated with inner chamber of cylinder block in the side of cylinder body, and cylinder body is located on the lower roof plate with displacement bar is all vertical.Because cylinder body of the present utility model is just put (the cylinder body opening upwards), so be called positively fixed type cylinder body pile reaction static test oil gear.

Cylinder body of the present utility model preferably also is provided with the protection outer cover outward, and displacement bar and oil inlet pipe preferably are provided with the protection steel bushing outward.

The of the present utility model use (being example): behind the large diameter pile pore-forming with large diameter pile, carry out at the end clearly earlier, and then fill up the middle rough sand of about 2 cm thicks and put into pressing plate and (can cast with concrete in advance, be generally 500 * 500), put into the utility model test oil pressure device then, build pile body again, stake is maintained after date and just can be tested.The utility model is disposable use.During test, add fluid by oil inlet pipe and begin pressurization, oil reaches in the cylinder body, along with pressure increases, piston just up and down top board move down, pile side resistance and end resistance are had an effect thereupon.The oil pressure station on ground is provided with tensimeter, can show institute's applied pressure size, and the relation of pressure and load should be demarcated in advance.A dial gauge on ground links to each other with the stake top, also has a dial gauge to link to each other with displacement bar, and two dial gauges all are bearing on the datum line beam.Measure the displacement (being downward displacement of concrete-pile stake subsoil and the displacement upwards of stake top) of piston and lower roof plate.In giving stake end loading process step by step, pile body to top offset and stake subsoil to bottom offset, thereby transfer stake side soil resistance and stake subsoil resistance and make both counter-forces each other.According to the reading of tensimeter and dial gauge, power that can be made progress accordingly and displacement relation figure and downward power and displacement relation figure have so also just obtained load-displacement curve (collateral resistance-displacement curve and end resistance-displacement curve).When any curve in two load-displacement curves reached destruction, test can come to an end, and thought that this failing load can be used as the design load or the allowable load of stake.

Because action and reaction power equates that the load that pile reaction static test method is applied is half of traditional pile testing method pile top load.Also can be according to executing step by step under the lotus, pile body is to poor to top offset of top offset and stake top, calculate the caused pile body elastic compression of a resistance, and the elastic modulus of sharp pile material, the estimation pile side resistance is along the distribution situation of pile body, and whether the bearing capacity that can be the single pile design bearing capacity and provide the stake that more theory or check constructed satisfies the practical requirement of engineering fully.

Advantage of the present utility model:

Device is simple, and the material that does not need to carry hundreds of or thousands of tons of does not need to construct heavy reaction frame as the ballast preloading yet, can increase test pile quantity like this, enlarges detection faces, for engineering construction provides safer guarantee coefficient.

Can be used to find out the side resistance or the end resistance individual event ultimate value of foundation pile, and the ultimate value of embedded rock pile build-in force (anchor force), these all are that conventional apparatus is difficult to accomplish.

In construction of road and bridge, owing to be subjected to the restriction ratio of geographical environmental condition bigger, must test detect if any engineering piles, just bigger with the conventional apparatus difficulty, as being resolved easily with the utility model.

The utility model extremely is suitable for test pile of narrow place test pile, harbour, offshore engineering and soft clay area in test pile waterborne, the city etc. and sets up preloading platform or the inconvenient situation of anchoring pile reaction frame.

Applicable to multiple foundation pile (boring (dashing) hole pouring pile or artificial digging pile, prestressed concrete pipe pile, hammer hidden pipe caisson pile etc.) as major diameter.As be driven pile, also can utilize same pile to beat to different depth, test one by one, therefrom long for the best stake of design alternative.

For having one in the skyscraper to the situation of several layers of basement, with traditional pile testing method, not only Shi Yan difficulty is bigger, and excavation of foundation pit gets too dark, do not allow exposure too of a specified duration, and construction speed is not allowed yet.If adopt the utility model, just can make things convenient for and record the bearing capacity of foundation pile effective length exactly, and before excavation of foundation pit, just can carry out this work.

With notification number is that " the pile bearing capacity determinator " that the Chinese patent literature of CN2305667X is announced compared, the utility model has the advantages that: 1,, solved the problem that stress is concentrated, the upper and lower steel plate of establishing because oil inlet pipe is located at the side, stress is disperseed, test safer more reliable; 2, just can normally connect the oil pipe standard component with existing technology,, utilize prior art to reconfigure because existing common separation formula lifting jack also is that oil nozzle is located at the side, easy for installation, make economical; 3, owing to adopted the positively fixed type hydraulic jack, can utilize many ready-made standard components, not do too much technological transformation, cost is lower.

Fig. 1 is the structural representation of embodiment.

Fig. 2 is embodiment riding position and a connection relation synoptic diagram in use.

Embodiment: see Fig. 1-2.By steel lower roof plate 1, external diameter is less than steel garden detective pole 2, that opening makes progress tubular cylinder body 3, the steel garden plunger pistons 4 that can move up in the cylinder body 3, and steel displacement bar 5 and oil inlet pipe 6 are formed.Oil inlet pipe 6 is communicated with cylinder body 3 inner chambers in the side of cylinder body 3, and cylinder body 3 is located on the lower roof plate 1 with displacement bar 5 is all vertical.The cylinder body 3 outer steel protection outer covers 7 that also are provided with, displacement bar 5 and the oil inlet pipe 6 outer protection steel bushings 8 that are provided with.9 pressing plates of the time putting into for test, 10 is the oil pressure station on ground, and 11 is dial gauge, and 12 is datum line beam.

Claims (2)

1, a kind of positively fixed type cylinder body pile reaction static test oil gear, it is characterized in that including lower roof plate, external diameter is less than cylinder body detective pole, that opening makes progress, the piston that can move up in the cylinder body, and displacement bar and oil inlet pipe, oil inlet pipe is communicated with inner chamber of cylinder block in the side of cylinder body, and cylinder body is located on the lower roof plate with displacement bar is all vertical.

2, as the said positively fixed type cylinder body of claim 1 pile reaction static test oil gear, it is characterized in that cylinder body is provided with the protection outer cover outward, displacement bar and oil inlet pipe are provided with the protection steel bushing outward.

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