Electronic large-scale strain control formula ring shear apparatus
Technical field
The invention belongs to the Geotechnical Engineering field, be specifically related to a kind of ring shear apparatus, particularly a kind of electronic large high-speed strain control formula ring shear apparatus.
Background technology
Ring shear apparatus is a kind of of Geotechnical Engineering field laboratory experiment instrument, is mainly used in the mensuration of ground motion shear strength parameters.For the slipping plane of natural landslide, the soil body can be because repeatedly sliding produce sizable distortion, when analysis of landslide stable, should adopt residual strength.The shearing strength that ring shear apparatus then can be measured ground is with the Changing Pattern that displacement increases, and is specially adapted to measure the residual strength of soil after the large displacement.
It is that soil sample is packed in the ring specimen box that ring is cut experiment, by the top increased pressure board sample is applied pressure at right angle, applies certain process that shearing makes its failure of reversing to soil sample on this basis.Ring shear apparatus is divided into two types by its architectural feature, i.e. monocyclic ring shear apparatus and dicyclic ring shear apparatus.Wherein, the monocyclic ring shear apparatus is that soil sample is packed in the monoblock type monocycle cylindrical shape shear box, certain shearing that reverses in addition when by increased pressure board soil sample being applied pressure at right angle, its shear failure of soil sample of using this kind ring shear apparatus to test is not to occur in soil sample inside, approach rotation increased pressure board place but come across, therefore measured data can not reflect the true mechanical index of soil sample.The dicyclic ring shear apparatus is that monoblock type monocycle shear box is designed to two annular shear boxs that separate up and down, the soil sample of using this kind ring shear apparatus to test is sheared along the default face of up and down ring box contact, realized that ring truly cuts, but this kind ring shear apparatus is the difficult control of spacing of shear box up and down, and squeeze-out phenomenon easily appears in soil sample in experimentation.
At present, domestic achievement about ring shear apparatus development and exploitation is still few, the ring shear apparatus of developing also mostly is small-sized ring shear apparatus, this kind ring shear apparatus shear box size is less than normal, and consequent stress concentration effect is larger on the impact of experimental data, and its loading is less, shear rate is also lower, maximal rate generally can only reach 1r/min, so its range of application is very limited, can not satisfy the needs of scientific research and engineering reality.By contrast, developed countries has carried out the long period the development of ring shear apparatus, large-scale ring shear apparatus and high automation ring shear apparatus are also come out one after another, but compression system and the jacking system of external ring shear apparatus all adopt hydraulic means, the stable work in work of this hydraulic means, reliability is better, but in use there are several large defectives in it, as in experimentation, easily producing seepage, exist and pollute; Be unfavorable for daily servicing, and maintenance cost is higher; Installation procedure is loaded down with trivial details especially, need to lay a large amount of pipelines, and these pipelines can bring inconvenience to experimentation, needs to be equipped with hydraulic power source and related accessory, such as hydraulic pump etc.In addition, external ring shear apparatus is expensive, and it is applied also and has difficulty in taking a step, domestic use very few.
Comprehensive above-mentioned situation as can be known, at present the domestic relevant independent development and exploitation that is fit to the large high-speed ring shear apparatus of requirement of engineering also belongs to blank, the shortage of instrument has limited the mensuration of correlation parameter greatly, and the further investigation of geologic hazard has been caused very big impact.
Summary of the invention
Defective or deficiency for above-mentioned prior art existence, the object of the invention is to, a kind of electronic large high-speed strain control formula ring shear apparatus is provided, this ring shear apparatus arranges gap control structure between upper shear box, down cut box, guarantee the up and down sealing of shear box, effectively prevent sample seepage in the experimentation; By gear drive and the control of controller realization speed, its maximum shear speed can reach 588cm/s, compares the ring rate of shear degree of domestic 1r/min, has realized high-speed annular shearing truly; Realize shear failure by gear mechanism transmission, the down cut box carries out is that annular is rotated, and can realize that sample shears under continuous displacement condition, realizes that namely shear displacemant do not limit.
In order to achieve the above object, the present invention adopts the scheme of following technology final result:
A kind of electronic large-scale strain control formula ring shear apparatus is characterized in that, comprises sole plate and platform; Described platform is installed in described sole plate top by support bar; Between platform and sole plate, be provided with controller, shear pinion wheel control module and shear box gap control unit; At platform cut cells and vertical unit are installed;
Described shearing pinion wheel control module comprises reducer casing, shearing pinion shaft, shearing moment sensor, shears pinion shaft front end block bearing, shears pinion shaft end bearing bearing, shears bevel gear pair and shear servomotor; Wherein, shearing servomotor is fixed on the described sole plate, the output terminal of shearing servomotor connects reducer casing, the output terminal of reducer casing connects a gear shearing bevel gear pair, and another gear of shearing bevel gear pair is installed on the sole plate by shearing pinion shaft end bearing bearing; Shear the top of bevel gear pair shearing pinion shaft and shearing moment sensor are installed successively; Wherein, the bearing of shearing moment sensor upper end is upward through platform and is connected with shearing pinion shaft front end block bearing;
Described shear box gap control unit comprises gap sensor, clearance control servomotor, gap adjustment bevel gear pair and axis, and wherein, axis passes platform, and the lower end of axis is installed intermittently sensor, gap adjustment bevel gear pair successively; The clearance control servomotor also is installed on the sole plate, and the output terminal of this clearance control servomotor is connected bevel gear pair and is connected with the gap;
Described cut cells comprises shear box, down cut box, upper shear box mounting disc, the mounting disc of down cut box, shears gear wheel, shears pinion wheel; Wherein, shear gear wheel and be positioned at platform central authorities, two fixed bars of symmetrical installation on the platform of shearing gear wheel both sides, the mounting disc of down cut box is fixed on shears on the gear wheel, and the top of down cut box mounting disc is coaxial installation down cut box, upper shear box and upper shear box mounting disc successively; Wherein, be connected by bolt between the mounting disc of down cut box and the down cut box, also be connected by bolt between upper shear box and the upper shear box mounting disc; Shear pinion wheel and be installed on the shearing pinion shaft front end block bearing, and shear pinion wheel and shear the gear wheel engagement;
Described vertical unit comprises symmetrically arranged two the first Linear-electric-cylinders, adapter sleeve, connecting link, top loading unit; Wherein, the top loading unit comprises pull pressure sensor, spherical hinge, the second Linear-electric-cylinder, crossbeam, balance stem, pressure at right angle distributing disc, transmission rod, increased pressure board; Wherein, the balance stem two ends are fixed on described two fixed bars upper end, the parallel balance stem below that is positioned at of crossbeam, and two fixed bars pass crossbeam and the relatively upper and lower slip of fixed bar of this crossbeam; Described two the first Linear-electric-cylinders are separately positioned on the outside of described two fixed bars by the Linear-electric-cylinder base, the electric cylinder axle of described two the first Linear-electric-cylinders is fixed on the two ends of crossbeam by connecting link and setscrew nut; The electric cylinder axle of the first Linear-electric-cylinder is connected with connecting link by adapter sleeve; The second Linear-electric-cylinder is fixed on the center of described crossbeam below; Below the second Linear-electric-cylinder, connect successively spherical hinge, pull pressure sensor and pressure at right angle distributing disc, below the pressure at right angle distributing disc, by the fixing increased pressure board of several transmission rods, be bolted the mounting disc of down cut box at the lower surface of increased pressure board;
The upper end of described axis is passed the center of shearing gear wheel, the mounting disc of down cut box, down cut box, upper shear box, upper shear box mounting disc and increased pressure board successively, and the middle shaft-cup that the upper end of this axis is fixed on the increased pressure board center covers;
Described clearance control servomotor, shear servomotor, two the first Linear-electric-cylinders, the second Linear-electric-cylinders, intermittently sensor, shearing moment sensor connect respectively controller.
The present invention also comprises following other technologies feature:
Described shearing servomotor is fixed on the described sole plate by shearing the servomotor base.
On the described sole plate support is installed, described controller is fixed on the described support, and described clearance control servomotor is fixed on the described support by clearance control servomotor base.
Described upper shear box mounting disc bottom outer surface evenly is provided with a plurality of sheet projections, also is provided with a plurality of sheet projections on the bottom surface in the mounting disc of down cut box.
Be provided with rubber ring between described down cut box and the described upper shear box.
The below of described pressure at right angle distributing disc is by the fixing described increased pressure board of a transmission rod.
Described ring shear apparatus also comprises pore water pressure sensor, and described pore water pressure sensor is installed in the hole that arranges on the described upper shear box sidewall.
Described ring shear apparatus also comprises the perpendicular displacement sensor, and described perpendicular displacement sensor is fixed on the fixed bar by the perpendicular displacement sensor stand, and the lower end of perpendicular displacement sensor contacts with the upper surface of described pressure at right angle distributing disc.
Described ring shear apparatus also comprises the shear displacemant sensor, and described shear displacemant sensor is fixed on the described fixed bar and with the mounting disc of described down cut box by the shear displacemant sensor stand and contacts.
Described ring shear apparatus also comprises the shearing resistance sensor, described shearing resistance installation of sensors on the described fixed bar and with described on the shear box mounting disc contact.
Compare with existing ring shear apparatus, the advantage of electronic large high-speed strain control formula ring shear apparatus of the present invention is as follows:
1, the present invention is the ring shear apparatus of dicyclic, in whole experimentation the down cut box with respect on the shear box initial ring to shearing, guaranteed that the area of shear surface remains constant.
2, the size of upper shear box, down cut box is by the 40cm of the shear box of domestic traditional instrument
2Increase to 392.7cm
2, it specifically is of a size of internal diameter 20cm, external diameter 30cm, maximum dress sample height 10cm.Improved the size effect that small sample is sheared, the experimental data that records can reflect the mechanical index of soil sample more realistically.
3, upper shear box, down cut box are made with the PEEK material.The PEEK material is a kind of thermoplastic special engineering plastic, has the performances such as good mechanical property and chemicals-resistant, wear-resistant, hydrolysis, and light specific gravity has extraordinary processing characteristics, can be injection molded into any high-strength transparence plastic part.The PEEK material has higher glass transition temperature and fusing point, and load thermal change type temperature is up to 316 ℃, and serviceability temperature is 260 ℃ continuously.In addition, the PEEK material has outstanding self lubricity in all plastics, is particularly suitable for being strict with low-friction coefficient and abrasion performance purposes and uses.Simultaneously, adopt transparent material making shear box to be more conducive to the experimenter and in experimentation, observe the sample state.
4, be provided with high-precision gap sensor and clearance control servomotor between upper shear box, the down cut box, guaranteed the sealing of upper and lower shear box, can effectively prevent sample seepage in the experimentation.
5, the present invention is a kind of high speed ring shear apparatus, by gear drive and the control of controller realization speed, its maximum shear speed can reach 588cm/s, compare the ring rate of shear degree of domestic 1r/min, realized that high-speed annular truly shears, for the research of landslide, mud-rock flow movement mechanism provides experiment condition.Simultaneously, therefore the range of application of ring shear apparatus has also obtained expansion, by being mainly used at first soil body research to residual strength character after shear surface generates, expand to and relate in the middle of the research relevant with soil body shear failure process, but the STRESS VARIATION that occurs such as sample in the situations such as simulated earthquake, underground water fluctuation, contingent liquefaction phenomenon etc.
6, the present invention mainly realizes shear failure by gear mechanism (namely shear pinion wheel 8, shear gear wheel 32) transmission, what the down cut box carried out is that annular is rotated, as long as shearing pinion wheel does not stop operating, shear box can produce a relative displacement up and down, can realize that sample shears under continuous displacement condition, realize that namely shear displacemant do not limit.In the sloping body of reality slided, it is much that the phenomenon of hundreds of meters of Mi Naizhi is counted in slip, and therefore these characteristics of the present invention are significant for the shear strength characteristics of Rock And Soil motion in the Study of Landslides.
7, the present invention adopts the vertical loading structure, abandon original hydraulic loading mechanism, the more advanced electric cylinder of employing technology applies vertical load, and be furnished with high-accuracy electron device (controller, shear displacemant sensor, shearing moment sensor, gap sensor, perpendicular displacement sensor, pore water pressure sensor, motor, reducer casing etc.) experimentation is controlled, can realize rapid loading, load and apply large load continuously.The maximum perpendicular load that the present invention can apply is 4 tons, and the maximum (normal) stress that imposes on sample can reach 1000kPa.Compare with hydraulic mechanism, electric cylinder has the stability suitable with it and reliability, also possesses simultaneously the inaccessible advantage of a lot of hydraulic mechanisms, and is light such as the electric cylinder system weight; Has good Long-term Storage characteristic; There is not fluid seepage, pollution-free problem; Be easy to detect, safeguard, operating cost is low; Easy for installation, simple plug-in type electromagnetic connects, and does not need to be equipped with the central liquid potential source, does not need to lay pipeline and leak check or pollution, only needs to lay electric line; Do not need cooling, the nominal load power efficiency is high.Except compression system adopts electric cylinder, the mechanism that finishes compression system lifting task equally also adopts electric cylinder, can say that adopting electric cylinder is the characteristics of maximum of the present invention.
8, each parts all adopts mechanical connection, especially conveniently carries out part replacement, has saved cost.
Description of drawings
Fig. 1 is structural representation of the present invention.The symbol implication is as follows among the figure: the 1-sole plate, the 2-reducer casing, 3-shears pinion shaft, 4-shearing moment sensor, 5-shears pinion shaft front end block bearing, the 6-platform, 7-Linear-electric-cylinder base, 8-shears pinion wheel, 9-shear displacemant sensor stand, 10-shear displacemant sensor, the 11-rubber ring, 12-shearing resistance sensor 13-the first Linear-electric-cylinder, the 14-pull pressure sensor, the 15-spherical hinge, the 16-adapter sleeve, 17-the second Linear-electric-cylinder, the 18-setscrew nut, the 19-crossbeam, the 20-balance stem, 21-perpendicular displacement sensor, 22-perpendicular displacement sensor stand, 23-pressure at right angle distributing disc, the 24-transmission rod, shaft-cup among the 25-, the 26-increased pressure board, the upper shear box mounting disc of 27-, the upper shear box of 28-pore water pressure sensor 29-, 30-down cut box, the mounting disc of 31-down cut box, 32-shears gear wheel, the 33-gap sensor, 34-clearance control servomotor, 35-clearance control servomotor base, the 36-support, bevel gear pair is adjusted in the 37-gap, the 38-axis, 39-shears pinion shaft end bearing bearing, 40-shears bevel gear pair, 41-shears the servomotor base, 42-shears servomotor, the 43-controller, the 44-support bar, the 45-fixed bar, the 46-connecting link.
Fig. 2 is the structural representation of the upper shear box mounting disc of back-off state.
Fig. 3 is down cut box mounting disc structural representation.
Fig. 4 is reducer casing inner structure schematic diagram.Wherein, (a) be overall structural arrangement figure; Label among the figure represents the gear sequence number, and the number of teeth of each gear is as follows: Z
47=25, Z
48=75, Z
49=50, Z
50=50, Z
51=65, Z
52=35, Z
53=85, Z
54=35, Z
55=75, Z
56=45, Z
57=40, Z
58=60, Z
59=40, Z
60=60, Z
61=35; Gear engagement arrangenent diagram when (b) being 1 grade; Gear engagement arrangenent diagram when (c) being 2 grades; Gear engagement arrangenent diagram when (d) being 3 grades; Gear engagement arrangenent diagram when (e) being 4 grades.
Below in conjunction with the drawings and specific embodiments the present invention is done further and to explain.
Embodiment
As shown in Figure 1, electronic large-scale strain control formula boxshear apparatus of the present invention comprises sole plate 1 and platform 6, and platform 6 is installed in sole plate 1 top by some support bars 44; Between platform 6 and sole plate 1, be provided with controller 43, shear pinion wheel control module and shear box gap control unit; At platform 6 cut cells and vertical unit are installed.
Described shearing pinion wheel control module comprises reducer casing 2, shearing pinion shaft 3, shearing moment sensor 4, shears pinion shaft front end block bearing 5, shears pinion shaft end bearing bearing 39, shears bevel gear pair 40 and shear servomotor 42; Wherein, shearing servomotor 42 is fixed on the sole plate 1 by shearing servomotor base 41, the output terminal of shearing servomotor 42 connects reducer casing 2, the output terminal of reducer casing 2 connects a gear shearing bevel gear pair 40, and another gear of shearing bevel gear pair 40 is installed on the sole plate 1 by shearing pinion shaft end bearing bearing 39; Shear the top of bevel gear pair 40 shearing pinion shaft 3 and shearing moment sensor 4 are installed successively; Wherein, the bearing of shearing moment sensor 4 upper ends is upward through platform 6 and shears pinion shaft front end block bearing 5 and be connected.
Described shear box gap control unit comprises gap sensor 33, clearance control servomotor 34, gap adjustment bevel gear pair 37 and axis 38, wherein, described axis 38 passes platform 6, and the lower end of axis 38 is installed sensor at described intermittence successively, bevel gear pair 37 is adjusted in the gap; Support 36 is installed on the sole plate 1, described controller 43 is fixed on the described support 36, described clearance control servomotor 34 is fixed on the support 36 by clearance control servomotor base 35, and the output terminal of this clearance control servomotor 34 is connected bevel gear pair 37 and is connected with the gap.
Described cut cells comprises shear box 29, down cut box 30, upper shear box mounting disc 27, down cut box mounting disc 31, shears gear wheel 32, shears pinion wheel 8, shear displacemant sensor 10 and shearing resistance sensor 12; Wherein, shear gear wheel 32 and be positioned at platform 6 central authorities, two fixed bars 45 of symmetrical installation on the platform 6 of shearing gear wheel 32 both sides, down cut box mounting disc 31 is fixed on shears on the gear wheel 32, and the top of down cut box mounting disc 31 is the described down cut box 30 of coaxial installation, upper shear box 29, upper shear box mounting disc 27 successively; Be provided with rubber ring 11 between down cut box 30 and the upper shear box 29; Arrange porosely on described upper shear box 29 sidewalls, pore water pressure sensor 28 is installed in this hole; Wherein, be connected by bolt between down cut box mounting disc 31 and the down cut box 30, also be connected by bolt between upper shear box 29 and the upper shear box mounting disc 27; Described shearing resistance sensor 12 is installed on the fixed bar 45 and with described upper shear box mounting disc 27 and contacts; Described shearing pinion wheel 8 is installed in to be sheared on the pinion shaft front end block bearing 5 and shearing pinion wheel 8 and 32 engagements of shearing gear wheel; Described shear displacemant sensor 10 is fixed on the fixed bar 45 and with down cut box mounting disc 31 by shear displacemant sensor stand 9 and contacts; Upper shear box mounting disc 27 bottom outer surfaces evenly are provided with a plurality of sheet projections (as shown in Figure 2), also are provided with a plurality of sheet projections (as shown in Figure 3) on the bottom surface in the down cut box mounting disc 31.
Described vertical unit comprises symmetrically arranged two the first Linear-electric-cylinders 13, adapter sleeve 16, connecting link 46, perpendicular displacement sensor 21 and top loading units; Wherein, the top loading unit comprises pull pressure sensor 14, spherical hinge 15, the second Linear-electric-cylinder 17, crossbeam 19, balance stem 20, pressure at right angle distributing disc 23, transmission rod 24, increased pressure board 26; Wherein, described balance stem 20 two ends are fixed on two fixed bar 45 upper ends, described crossbeam 19 parallel balance stem 20 belows that are positioned at, and two fixed bars 45 pass described crossbeam 19 and relatively fixed bar 45 upper and lower slips of crossbeam 19; Two the first Linear-electric-cylinders 13 are separately positioned on the outside of two fixed bars 45 by Linear-electric-cylinder base 7, the electric cylinder axle of two the first Linear-electric-cylinders 13 is fixed on the two ends of crossbeam 19 by connecting link 46 and setscrew nut 18, the electric cylinder axle of the first Linear-electric-cylinder 13 is connected with connecting link 46 by adapter sleeve 16; The second Linear-electric-cylinder 17 is fixed on the center of crossbeam 19 belows; Below the second Linear-electric-cylinder 17, connect successively described spherical hinge 15, pull pressure sensor 14 and pressure at right angle distributing disc 23, below pressure at right angle distributing disc 23, by several (being generally 3) transmission rod 24 fixing described increased pressure boards 26, be bolted down cut box mounting disc 27 at increased pressure board 26 lower surfaces; Described perpendicular displacement sensor 21 is fixed on the fixed bar 45 by perpendicular displacement sensor stand 22, and the lower end of perpendicular displacement sensor 21 contacts with the upper surface of pressure at right angle distributing disc 23.
The upper end of described axis 38 is passed the center of shearing gear wheel 32, down cut box mounting disc 31, down cut box 30, upper shear box 29, upper shear box mounting disc 27, increased pressure board 26 successively, and the middle shaft-cup 25 that the upper end of this axis 26 is fixed on increased pressure board 26 centers covers.
Described clearance control servomotor 34, shear servomotor 42, two the first Linear-electric-cylinders 13, the second Linear-electric-cylinders 17, intermittently sensor 33, shearing moment sensor 4 connect respectively described controller 43.
Below be in the present invention roles of above-mentioned each parts:
Sole plate 1 is used for keeping the stability of whole instrument; Reducer casing 2 is used for providing the shear rate of different gears; Shearing moment sensor 4 is used for measuring the shearing moment that is applied on the sample; Platform 6 is used for supporting cut cells, vertical unit; Linear-electric-cylinder base 7 is used for installing the second Linear-electric-cylinder 17; Shearing pinion wheel 8 rotates for the shearing gear wheel 32 that drives with its engagement; Shear displacemant sensor stand 9 is used for fixed shear displacement transducer 10; Shear displacemant sensor 10 is used for measuring the displacement vector of shear surface; Rubber ring 11 is for the frictional resistance that reduces between upper shear box and the down cut box; Shearing resistance sensor 12 is used for measuring the frictional resistance at shear history shear surface place; The first Linear-electric-cylinder 13 is used for lifting increased pressure board 26; Pull pressure sensor 14 is used for measuring the second Linear-electric-cylinder 17 and is applied to magnitude of load on the pressure distribution dish 26; Spherical hinge 15 is used for guaranteeing the axis centering of vertical load and instrument, the eccentric heeling moment that produces of the power that prevents; Adapter sleeve 16 is used for connecting the electric cylinder axle of connecting link 46 and the first Linear-electric-cylinder 13; The second Linear-electric-cylinder 17 provides vertical load for the sample in shear box; Setscrew nut 18 is used for the balance of the first Linear-electric-cylinder 17 of adjustment both sides; Crossbeam 19 is used for fixing and being connected the first Linear-electric-cylinder 17; Perpendicular displacement sensor 21 is used for measuring the perpendicular displacement of pressure at right angle distributing disc 23 to calculate the vertical deformation of sample; Perpendicular displacement sensor stand 22 is used for fixed vertical displacement transducer 21; Pressure at right angle distributing disc 23 is used for pressure at right angle is distributed in each transmission rod 24; Transmission rod 24 is used for pressure at right angle is reached increased pressure board 26; Middle shaft-cup 25 is used for covering the upper end of axis; Increased pressure board 26 is used for applying pressure at right angle to sample; Upper shear box mounting disc 27 is used for fixing upper shear box 27; Pore water pressure sensor 28 is used for measuring the pore water pressure of sample; Upper shear box 29, down cut box 30 are all for placing sample; Down cut box mounting disc 31 is used for fixedly down cut box 30; Shear gear wheel 32 and be used under the drive of shearing pinion wheel 8, driving shear box 30 rotations; Gap sensor 33 is used for measuring the clearance distance of upper shear box, down cut box; Clearance control servomotor 34 is used for the gap length between the upper shear box of control, down cut box; Clearance control servomotor base 35 is used for fixed interval (FI) control servomotor 34; The gap is adjusted bevel gear pair 37 and is used for rotatablely moving of clearance control servomotor 34 is converted to the leading screw axially-movable; Axis 38 is used for regulating the gap of upper and lower shear box under the drive of clearance control servomotor 34; Shear bevel gear pair 40 and be used for transmitting the moment of torsion of speed reduction unit 2 outputs; Shearing servomotor 42 is used to whole instrument that power source and control loop rate of shear degree are provided; Controller 43 is used for control gap control servomotor 34, shear the rotating speed of servomotor 42 and two the first Linear-electric-cylinders 13, the lifting displacement of the second Linear-electric-cylinder 17.
Principle of work of the present invention is as follows:
Electronic large high-speed strain control formula ring shear apparatus of the present invention utilization is taken from on-the-spot disturbed sample and is tested.The experiment initial stage, bolt between upper shear box and the upper shear box mounting disc is unfixing, the power supply of the Linear-electric-cylinder 13 of two symmetries is started working it about connection, this moment, the top load maintainer (comprised member 14,15,17,19,20,23,24,26) and upper shear box mounting disc 27 together by Integral lifting, when rising to the extreme higher position and namely reach the maximum lift displacement that controller 43 sets, about two Linear-electric-cylinders 13 quit work, this moment sample is packed in upper shear box 29 and the down cut box 30, two Linear-electric-cylinders 13 reverse about again starting after the sample filling is finished, the top load maintainer begins to descend, until upper shear box mounting disc 27 when contacting with upper shear box 29 electric cylinder 13 quit work, and upper shear box mounting disc 27 and upper shear box 29 usefulness bolts are fixed, then can carry out the main body experiment.
After the main body experiment formally begins, at first starting the second Linear-electric-cylinder 17 moves downward its lead screw shaft, apply a certain size pressure at right angle by requirement of experiment to pull pressure sensor 14, pull pressure sensor 14 is passed to pressure at right angle again pressure at right angle distributing disc 23, passes 24 to increased pressure board 26 by transmission rod again.Because upper shear box mounting disc 27 bottom evens arrange a lot of sheet projections, under the effect that is subject to upper vertical pressure, these sheet projections embed in the sample soil body, the friction force of shear box mounting disc 27 and sample on when applying pressure at right angle to sample, having increased, thereby guaranteed that the sample in the upper shear box keeps stable, does not rotate with sample in the down cut box.
After loading procedure was finished, the control that servomotor 42 is realized shear rate was sheared in controller 43 controls, and by reducer casing 2 realize target moments of torsion, in the shear history, the inner structure state of reducer casing 2 as shown in Figure 4.
Moment of torsion by reducer casing 2 outputs passes to shearing pinion shaft 3 by shearing bevel gear pair 40, and the shearing moment sensor 4 of installing on the top of shearing pinion shaft 3 is measured the shearing moment that is applied on the sample.The rotation of shearing pinion shaft 3 has driven and has been installed in shearing pinion wheel 8 rotations of shearing on the pinion shaft 3, rotate with the shearing gear wheel 32 of shearing pinion wheel 8 engagements thereupon, down cut box mounting disc 31 is fixed on shears on the gear wheel 32, and down cut box mounting disc 31 is rotated simultaneously.Because a lot of sheet projections evenly being set on the bottom surface in the down cut box mounting disc 31, under the effect that is subject to upper vertical pressure, these sheet projections embed in the sample, so that the sample that down cut box mounting disc 31 has driven in the down cut box 30 rotates, and finally realized the annular shear failure of sample when rotating.
Gap sensor 33 Real-time Collection gap signal and send controller 43 in experimentation, whether controller 43 real-time judge gaps are in normal range, if undesired, then real-time control gap is controlled the rotating speed of servomotor 34, thereby adjusting gear pair 37 drive axis 38 by the gap moves up and down, middle shaft-cup 26 is withstood in axis 38 upper ends, thereby drive increased pressure board 26, upper shear box mounting disc 27 and upper shear box 29 integral body and do upper and lower motion, realize adjusting upper and lower shear box gap to appropriate clearance.
The moment of torsion of shearing moment sensor 4 Real-time Collection reducer casing 2 outputs in experimentation, and signal passed to controller 43, controller 43 is regulated the rotating speed of shearing servomotor 42 according to the required shear rate of experiment, if moment of torsion or rotating speed can not be satisfied the demand, can realize by reducer casing 2 gearshifts.
Shear displacemant sensor 10, shearing resistance sensor 12, pull pressure sensor 14, perpendicular displacement sensor 21 and pore water pressure sensor 28 all are measuring units, are used for gathering experimental signal, do not participate in regulation and control.