Self-balancing static load measuring method for pile
Technical field
The present invention relates to a kind of device that the civil engineering work pile foundation is measured the pile body load-bearing capacity that is used for, especially relate to a kind of pile body self-balancing static load that in pile foundation, adopts and detect the self-balancing static load measuring method for pile of pile bearing capacity value.
Background technology
At present, detect the pile bearing capacity value in the pile foundation engineering two kinds of methods are arranged: be i.e. static load peg method and high strain dynamic test method; Described static load peg method has two kinds of methods again: i.e. an anchoring pile reversed beam method and a stake top preloading loading method; Static load peg accurate peg method owned by France.
Yet, a described anchoring pile reversed beam and a bridge pile body that preloading loading method in top all can't detect the pile body of super-large diameter, super bearing capacity value and stride rivers, ocean.
Described high strain dynamic test method has kind surplus hammering method, the hydroelectric effect method etc. ten, generally needs detect through after the dynamic and static testing comparison, and its degree of accuracy only reaches 80 percent.
Self-balancing static load peg bearing capacity technology begins in the U.S. and uses in states such as Europe, Japan, Canada subsequently from the eighties.Also widely apply and promote in China at present.Number be that the utility model patent of 97236934.1 " pile bearing capacity determinator " and Chinese patent application number are the utility model patent of 00219842.8 " pile bearing capacity is measured and used the load case " wherein as Chinese patent application, as shown in Figure 5, it is by lower roof plate, top offset sensor and bottom offset sensor are formed, described lower roof plate is provided with the hydraulic jack of external diameter less than detective pole, described hydraulic jack is made up of cylinder body and piston, described piston and described lower roof plate offset, on described cylinder body, be provided with oil inlet pipe, described top offset sensor is located on the cylinder body, and described bottom offset sensor is located on the lower roof plate.Described bottom offset sensor outer cover is provided with running casing, and described top offset sensor outer cover is provided with sleeve pipe.
The outside of described cylinder body is provided with support housing, is provided with upper plate at the top of described oil cylinder, and described support housing is fixed with described upper plate and described lower roof plate respectively, and being fixed as of one of them fixedly secures.
Above-mentioned application number is that 97236934.1 utility model patents " pile bearing capacity determinator " and Chinese patent application number are the routine techniques that utility model patent is only chatted and load is provided with of 00219842.8 " pile bearing capacity is measured and use the load case ", and the burying technology of key is not described with the survey survey technology; Wherein do not describe described displacement transducer again yet and how be converted to corresponding displacement by the actual measurement strain of resistance strain gage.And adopt described displacement transducer extend ground when loading to detect the load case displacement sum of described displacement transducer be the shift value of detected stake, and draw out load-displacement curve thus, promptly the Q-S curve is judged the ultimate bearing capacity value of detected stake; And described upper plate is isolated with pile body respectively by described upward sleeve pipe and described running casing with upper transfer sensor and bottom offset sensor that described lower roof plate is fixedlyed connected respectively; The displacement sum of described upper transfer sensor and bottom offset sensor is the displacement between described cylinder body and the piston; Yet not deduction stake top rising displacement.Above-mentioned testing result and stake top loads static load peg method and compares the ultimate bearing capacity value that appearance reaches detected stake too early, and the actual error of the ultimate bearing capacity value of mensuration is about 10 to percent 30.Thereby cause the waste of resource.Next is for then detecting as some pile bodies such as the uplift pile of saturated soft ground, manually digging hole club-footed piles.
Summary of the invention
Purpose of the present invention is exactly in order to overcome above-mentioned weak point of the prior art, provides a kind of the realization to detect the self-balancing static load measuring method for pile that cost can reduce greatly, can accurately detect the pile body of major diameter, super bearing capacity value and stride the bridge pile body of rivers, ocean with a peg technology of the degree of accuracy that the static load peg method that the top loads is identical.
The objective of the invention is by providing a kind of self-balancing static load measuring method for pile with following scheme to realize: described pile body is a detective pole, described detective pole is selected equilibrium point and is divided into the epimere stake and the hypomere stake, described epimere stake below connects a upper steel plate, and a lower steel plate is connected above the described hypomere stake.Described lower steel plate is provided with the load case that oil cylinder and piston component be made of of external diameter less than detective pole, described piston and described lower steel plate offset, on described cylinder body, be provided with oil inlet pipe, described lower steel plate is provided with displacement sensor rod, described displacement sensor rod outer cover is provided with sleeve pipe, and described upper steel plate is connected with the top of described oil cylinder.
Be connected the described load case that is made of oil cylinder and piston component between described epimere stake and the described hypomere stake, described load case adopts a plurality of oil cylinders and piston assembly structure according to the diameter of described detective pole with the estimation bearing capacity value; Or single oil cylinder and piston assembly structure.
Described hypomere stake is fixed with a plurality of described displacement bars, the fixedly connected described hypomere stake of described displacement bar top, and described displacement bar outer cover is equipped with sleeve pipe, and described displacement bar, described sleeve pipe are drawn in ground.
The stake top rising value sum of shift value when described displacement bar loads and described epimere stake is the stake top shift value that the stake top loads the static load peg.
Also can be provided with the displacement transducer of a plurality of tape test lines between described upper steel plate and the described lower steel plate, described p-wire periphery is provided with the test spool, and described p-wire, test spool lead to ground.
Described sleeve pipe, described test spool are provided with the extensible position of vertically ending button-type that not immersed by slime water between described upper steel plate and described lower steel plate, the span at described extensible position is determined by the extreme displacement value of described displacement bar.
The difference of the stake top rising value of shift value when described displacement transducer loads and described epimere stake is the stake top shift value that the stake top loads the static load peg.
Described a plurality of oil cylinder and piston component are set to 2~10 according to the diameter of described detective pole with the estimation bearing capacity value.
The centre of described upper steel plate, described lower steel plate is provided with macropore; The limit week position of described upper steel plate and described lower steel plate is provided with a plurality of apertures.
The vertical direction of described lower steel plate bottom surface is welded with the skeleton of many reinforcing bars, and the skeleton of described many reinforcing bars and described hypomere stake pouring are fixed with one; The vertical direction of described upper steel plate end face is welded with the skeleton of many reinforcing bars, and the skeleton of the many reinforcing bars of vertical direction of described upper steel plate end face and described epimere stake pouring are fixed with one.
Be divided into 10~15 grades according to detecting stake estimation bearing capacity value, eucalyptus is estimated the hierarchical loading of bearing capacity value and can record the shift value of hypomere stake and the stake top rising shift value sum of epimere stake with described displacement bar detection that the shift value of described hypomere stake is this grade load in the identical actual displacement value of stake top loading with the difference that the stake top rising shift value sum of epimere stake can record shift value with described displacement transducer detection.Can draw out load-displacement curve according to loads at different levels and shift value is the Q-S curve map, draws the ultimate bearing capacity value of stake thus.
Described oil inlet pipe is installed on the described upper steel plate, and an end of described oil inlet pipe is drawn ground, and the other end of described oil inlet pipe is connected with a ring-type oil pipe, and described ring-type oil pipe connects each oil cylinder and piston component.
Described oil inlet pipe is by steel pipe manufacturing; Described oil inlet pipe also can be made by flexible pipe.
Described sleeve pipe, described test spool extensible position outer setting rubber sealing boot is arranged.
Compared with prior art, the invention has the advantages that: 1. detect the degree of accuracy height, its degree of accuracy is consistent with the degree of accuracy of stake top loading static load peg; 2. displacement bar and sleeve pipe can reduce half, do not establish epimere stake displacement bar and sleeve pipe, and directly survey hypomere stake and stake top rising value; Adopt the displacement transducer can be again, thereby realize the simplification of pick-up unit, save engineering time and cost fully without displacement bar and sleeve pipe.
Description of drawings
Fig. 1 is epimere stake of the present invention and the embedding structural representation of hypomere stake;
Fig. 2 is that load case of the present invention and displacement bar are arranged synoptic diagram;
Fig. 3 is that load case of the present invention and displacement transducer are arranged synoptic diagram;
Fig. 4 is the extensible position structural representation of sleeve pipe of the present invention, test spool;
Fig. 5 is a kind of prior art constructions synoptic diagram;
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
Fig. 1 to Fig. 5 illustrates an embodiment of self-balancing static load measuring method for pile of the present invention.The principle of self-balancing static load measuring method for pile of the present invention is to choose the counterweight balance point at the pile body of tested peg to bury load case 3 underground, as shown in Figure 1.It is as follows with the equilibrium condition formula of hypomere stake 2 to estimate epimere stake 1 by the pile foundation standard:
(the stake friction resistance sum of epimere stake 1) 0.6~0.7u ∑ h
iq
Si
=(the stake friction resistance and the end resistance sum of hypomere stake 2) u ∑ h
iq
Si+ A*q
p
The section girth (rice) of u-stake in the formula;
The section horizontally-projected area of A-stake (square metre);
q
Si-iThe side friction of layer soil (kPa);
h
I-iThe thickness (rice) of layer soil;
q
P-1The end resistance of stake end soil (kPa);
When load case 3 loaded, pile body produced outside the elastic compression, and hypomere stake 2 produces and penetrates into displacement t
1, the stake top of epimere stake 1 produces rising displacement t
2
When the stake friction resistance sum of epimere stake 1 can't satisfy equilibrium condition, then can load also available screw anchor or vacuum earth anchor on the stake top.Load case embedding rock pillar can be embedded in the bottom of stake.
Load case 3 adopts the oil cylinder and the piston component 31 of single oil cylinder or heavy wool cylinder structure according to the diameter of stake with estimating bearing capacity value.Oil cylinder and upper steel plate 33 welding are fixing; Load case 3 is fixing with lower steel plate 34 welding.
Single oil cylinder is only applicable to pile for prestressed pipe; And on-the-spot pouring stake is annotated the load case that pile bodies such as stake, artificial digging pile, support disk pile must adopt the heavy wool cylinder structure as the stake of drill pipe notes, immersed tube pipe, and the centre of the upper steel plate 33 of load case 3 and lower steel plate 34 is provided with hole, and hole is used for concrete is poured into hypomere stake 2.
The fixedly connected displacement bar 4 in hypomere stake 2 tops of load case, displacement bar 4 outer cover are equipped with steel pipe and draw ground.Load case 3 connects an oil pipe 6 and draws ground, and oil pipe 6 connects an oil pump device.
Be divided into 10~15 grades according to detecting stake estimation bearing capacity value, classification by the estimation bearing capacity value can record the shift value of hypomere stake 2 and the stake top rising shift value sum of epimere stake 1, and the shift value of described hypomere stake 2 is this grade load with the stake top rising shift value sum of epimere stake 1 and loads identical actual displacement value on the stake top.Can draw out load-displacement curve according to loads at different levels and shift value is the Q-S curve map, draws the ultimate bearing capacity value of stake thus.
Also can measure oil cylinder in oil cylinder and the piston component 31 and the shift value between the piston, cut a top rising shift value (t among Fig. 2 then with the upper steel plate 33 of load case, displacement transducer that lower steel plate 34 is fixedlyed connected
2Value), being stake is equivalent to top loading and carries following actual top shift value.
First embodiment of self-balancing static load measuring method for pile of the present invention: adopt displacement bar to measure scheme, as shown in Figure 2.Be provided with load case 3 between upper steel plate 33 and the lower steel plate 34.Load case 3 is made up of single or multiple oil cylinders and piston component 31.Connect a upper steel plate 33 at the top of described oil cylinder, connect a lower steel plate 34, one of them be fixed as and fixedly secure of described oil cylinder and described piston at the root of described piston.
The vertical direction of described lower steel plate 34 bottom surfaces is welded with the skeleton 8 of many reinforcing bars, and the skeleton 8 of many reinforcing bars is fixed with one with hypomere stake 2 pourings.The vertical direction of described upper steel plate 33 end faces is welded with a plurality of frameworks of steel reinforcement 7, and framework of steel reinforcement 7 is fixed with one with epimere stake 1 pouring.
Be fixed with the displacement bar 4 of two band sleeve pipes 16 with hypomere stake 2, displacement bar 4 with well leads to ground.Upper steel plate 33 is equipped with the pressure oil pipe 6 that connects oil pump device, and an end of pressure oil pipe 6 is drawn ground, and the other end of pressure oil pipe 6 is connected with a ring-type oil pipe 5, and ring-type oil pipe 5 is transported to each oil cylinder and piston component 31 with the pressure oil connection, uses to do to load.
Second embodiment of self-balancing static load measuring method for pile of the present invention: adopt displacement transducer to measure scheme, as shown in Figure 3.Be provided with load case 3 between upper steel plate 33 and the lower steel plate 34.Load case 3 is made up of single or multiple oil cylinders and piston component 31.Connect a upper steel plate 33 at the top of described oil cylinder, connect a lower steel plate 34, one of them be fixed as and fixedly secure of described oil cylinder and described piston at the root of described piston.
The vertical direction of described lower steel plate 34 bottom surfaces is welded with the skeleton 8 of many reinforcing bars, and the skeleton 8 of many reinforcing bars is fixed with one with hypomere stake 21 pourings.The vertical direction of described upper steel plate 33 end faces is welded with a plurality of frameworks of steel reinforcement 7, and framework of steel reinforcement 7 is fixed with one with epimere stake 1 pouring.
Be provided with the displacement transducer 10 of tape test line 13 between upper steel plate 33 and the lower steel plate 34, p-wire 13 peripheries of displacement transducer 10 are provided with test spool 14, and p-wire 13 passes from test spool 14 and leads to ground.
Upper steel plate 33 is equipped with the pressure oil pipe 6 that connects oil pump device, and an end of pressure oil pipe 6 is drawn ground, and the other end of pressure oil pipe 6 is connected with a ring-type oil pipe 5, and ring-type oil pipe 5 is transported to each oil cylinder and piston component 31 with the pressure oil connection, uses to do to load.
The implementation process of self-balancing static load measuring method for pile of the present invention is as follows:
Determine the specification of upper steel plate 33 and lower steel plate 34 according to the diameter of tested peg, upper steel plate 33 is provided with macropore 35 with the centre of lower steel plate 34; Upper steel plate 33 is provided with a plurality of apertures 36 with the limit week position of lower steel plate 34.Estimate bearing capacity value according to tested peg, and add 20 percent oil cylinder specification and the quantity of choosing in oil cylinder and the piston component 31 according to the estimation bearing capacity value of tested peg.Oil cylinder in oil cylinder and the piston component 31 and piston are individually fixed in upper steel plate 33 and lower steel plate 34.Each oil cylinder is connected with a ring-type oil pipe 5 respectively in oil cylinder and the piston component 31, and ring-type oil pipe 5 is connected with the output pressure oil pipe 6 of oil pump device again.Pressure oil pipe 6 is made by steel pipe or flexible pipe, as shown in Figure 3.Pressure oil pipe of being made by steel pipe or flexible pipe 6 and displacement bar 4, displacement transducer 10, p-wire 13, p-wire cover 14, displacement bar sleeve pipe 16 all lead to ground.
The bottom surface of the displacement bar 4 of hypomere stake 2, displacement transducer 10, sleeve pipe 16 and lower steel plate 34 welding are fixing; Sleeve pipe 16 between upper steel plate 33 and the lower steel plate 34 is provided with extensible position 18.The periphery of sleeve pipe 16 all is nested with rubber tube 18, gives seal protection, as shown in Figure 4.
Displacement transducer 10 is fixed in the bottom surface of upper steel plate 33.The load case of being made up of oil cylinder and piston component 31 3 can combine application with displacement bar 4 schemes and displacement transducer 10 schemes in engineering, equal detection effect is all arranged.
Divide the load level to start oil pump device routinely and load, record the shift value of the stake of each load level.Adopt displacement bar 4 schemes among Fig. 2, displacement bar 4 deflections that the shift value of the stake of this load level is hypomere stake 2 add a top rising value (t among Fig. 2
2Value).
Adopt displacement transducer 10 schemes among Fig. 3, the shift value of the stake of this load level is the shift value that displacement transducer 10 records and deducts a top rising value (t among Fig. 1
2Value); Continuous successively level loads and records the vertical displacement value of stake.Drawing out load-displacement curve by standard is the Q-S curve map, to judge the ultimate bearing capacity value of stake.
Detect the back stake and broken, the sleeve pipe 16 of place displacement bar 4 is provided with the extensible position 18 of vertical strip notch grout outlet between upper steel plate 33 and lower steel plate 34, and it is outside with rubber tube 18 sealings, as shown in Figure 4.
Between upper steel plate 33 and lower steel plate 34, be provided with the extensible position 18 of vertical strip notch grout outlet as the p-wire sleeve pipe 14 of wearing detecting position displacement sensor 10 among Fig. 3, it is outside with rubber tube 18 sealings, as shown in Figure 4, the reinforcement of being in the milk still can reach the requirement of the anti-bearing capacity value of normal engineering.