CN201145658Y - Portable Field and Indoor Direct Shear Tester - Google Patents

Abstract

A portable on-site and indoor dual-purpose direct shear tester that can not only test the in-situ soil strength on site, but also test undisturbed soil samples and disturbed soil samples indoors. The tester includes sampling equipment, a mobile vertical pressurization system and a horizontal tension and shear system. The horizontal tension and shear system overcomes the rigid jacking method of the prior art and solves the problem of friction and sample deflection. The mobile vertical pressure system can ensure that the vertical pressure will not be eccentric during the test and improve the test accuracy. It is to put the soil sample containing the rigid frame obtained on site or prepared in the room into the rigid frame base fixed on the box frame, and apply vertical load through the mobile vertical loading system installed on the box frame. The strength of the soil is tested using a tensile shear frame, which does not limit the volume change in the vertical direction of the sample during the test; the instrument has a simple structure, is easy to operate, and is easy to carry.

Description

Portable Field and Indoor Direct Shear Tester

1. Technical field

The utility model relates to a direct shear test instrument for soil strength testing, which can not only test the strength parameters of natural soil slopes, filling soil slopes and various foundation surfaces conveniently and quickly on the spot, but also test the original soil samples indoors. , Reshape the strength parameter of the soil sample.

2. Background technology

Direct shear test instruments are divided into indoor test direct shear instruments and field test direct shear instruments. The conventional indoor direct shear tester has two shear boxes, upper and lower. After the sample is placed in the shear box, a certain vertical pressure is applied on the top of the sample to push the shear box, so that the sample is sheared until it is destroyed, thereby Get the strength parameters of the soil. At present, because the method of pushing the shear box is used to make the sample be sheared, the shear box and the measuring ring must be rigidly connected. During the shearing process, if the volume of the sample changes, friction will be generated at its contact point, and this friction cannot be measured in the test, so that the normal stress on the shear surface is inconsistent with the actual applied normal stress. Affects the correct testing of soil strength. Most of the field test direct shear instruments just increase the size of the indoor test direct shear instrument, and there is also the problem of friction at the rigid connection point.

3. Contents of the invention

The purpose of the utility model is to solve the frictional influence problem at the rigid connection point in the conventional direct shear tester. The technical solution adopted is to change the shearing mode of the sample from the rigid pushing mode to the flexible tensioning mode; the sampling device is directly used as the lower shear box, which can be directly tested on site; and the direct shear instrument can also be used indoors. Undisturbed or remodeled direct shear test. The whole set of equipment can be packed into a box-shaped frame, which is easy to carry.

The technical solution adopted by the utility model to solve the technical problem: put the soil sample containing the rigid frame obtained on the spot or prepared indoors into the rigid frame base, and the rigid frame base is fixed on the box-shaped frame. The sample is sheared by installing a mobile vertical loading system on a box frame, and then tensioning the shear frame with a flexible rope chain. During the test, the volume of the sample in the vertical direction will not be restricted by the flexible rope chain. The principle of this tester is simple, and it is easy to operate, and it can quickly measure the shear strength of the field soil, the original sample and the remodeled sample in the room. The whole device can be packed into a box-shaped frame, which is easy to carry.

A portable on-site and indoor dual-purpose direct shear tester, including sampling equipment and a vertical loading system, is characterized in that it also includes a horizontal tension and shear system, wherein the sampling equipment is composed of a shear frame 2 and a rigid frame 3. The cutting frame 2 is placed on the upper part of the rigid frame 3, and the vertical loading system is mobile, in which two beam pillars 18 are respectively fixedly connected to two rams 34 of the roller system 30, and the pulley system is composed of two roller guide rails 31 , two rollers 32 are embedded in the U-shaped groove of the roller guide rail 31, and the roller bearing 33 connects the rollers 32 with the ram 34; one end of the two chains 12 in the horizontal tension and shear system is respectively connected to the shear frame 2 On the chain hook 11 on the top, the other end is connected to the steel ring at one end of the connecting piece 14, and the other end of the connecting piece 14 is connected to the tension sensor 13 by threads, and the other end of the tension sensor 13 is connected with the threaded hand wheel push rod 15, the hand wheel 16 is connected with the hand wheel push rod 15, when the hand wheel 16 is turned, the hand wheel push rod 15 can move forward or backward, and the horizontal tension and shear system is fixed on the box frame 7 by bolts 17.

The above-mentioned portable on-site and indoor dual-purpose direct shear tester is characterized in that the shearing frame 2 is a square frame of a cross frame 28, and there are two chain hooks 11 on one side of the shearing frame 2, and its central part A horizontal displacement meter 6 is erected, and the net size of the rigid frame 3 is the same as that of the shear frame 2. The outer four surfaces of the lower ends of the two are knife-edge shapes. The rigid frame 3 is placed in the rigid frame base 4 and fixed with screws 8 , The rigid frame base 4 is fixed on the box frame 7 with bolts 27 again.

The above-mentioned portable on-site and indoor dual-purpose direct shear tester is characterized in that the lower end of the force transmission column 10 in the vertical loading system is fixed on the force transmission plate 9, the centers of the two are on the same vertical straight line, and the two The center line of the latter passes through the center of the sample 1, the bottom surface size of the force transmission plate 9 is the same as the plane size of the shear frame 2, the upper part of the force transmission plate 9 is equipped with a vertical displacement gauge 5, and the other end of the force transmission column 10 passes through the lever Bearing 19 is connected with lever 24 and fulcrum end cover 20, and the end of lever 24 is suspension plate 25, and the lower end of suspension plate is weight 26, and pillar 29 has thread, and its lower end is screwed into fulcrum end cover 20 li, and uses support nut I21 Fixed, the upper end of the pillar 29 is placed in the center hole of the crossbeam 23, and can move up and down, so that the force transmission plate 9 and the force transmission column 10 can be vertically adjusted in height as required. After the height is adjusted, the pillar 29 can be adjusted by The pillar nut II22 is fixed on the crossbeam 23, the crossbeam 23 is supported by two crossbeam pillars 18, and is fixed by the nut 35, the other end of the crossbeam pillar 18 has a screw thread, which is screwed into the ram 34, and the ram 34 is set outside the roller guide rail 31 , roller guide 31 has upper and lower two, and lower roller guide is fixed on the box frame 7, and the two ends of two roller guides 31 are fixed by the bolt 36 of fixing upper and lower roller guide.

The chains 12 in the horizontal tension and shear system of the above-mentioned portable on-site and indoor dual-purpose direct shear tester are two steel chains or steel wire ropes, each about 15 cm long.

The beneficial effects of the utility model are: 1) the whole set of equipment is simple in structure, easy to operate, and easy to carry; 2) it overcomes the influence of the friction force produced by the rigid contact shear box in the conventional direct shear test on the test results, and can truly reflect the soil The volume change when being sheared; 3) It has the advantages of both on-site and indoor use; 4) The mobile vertical loading system is used to apply vertical force to ensure that the vertical pressure will not be eccentric during the test.

4. Description of drawings

Fig. 1 is the structural representation of portable field, indoor dual-purpose direct shear tester;

Fig. 2 is the plane schematic diagram of portable on-site, indoor dual-purpose direct shear tester;

Fig. 3 is a side schematic diagram of a portable on-site and indoor dual-purpose direct shear tester;

Fig. 4 is the schematic diagram of the roller system of the portable on-site and indoor dual-purpose direct shear tester;

Reference signs: 1. Sample, 2. Shearing frame, 3. Rigid frame, 4. Rigid frame base, 5. Vertical displacement gauge, 6. Horizontal displacement gauge, 7. Box frame, 8. Rigid frame fixing screw , 9. Force transmission plate, 10. Force transmission column, 11. Chain hook, 12. Chain, 13. Tension sensor, 14. Connector, 15. Handwheel push rod, 16. Handwheel, 17. Handwheel fixing bolt , 18. beam strut, 19. lever bearing, 20. fulcrum end cover, 21. strut nut I, 22. strut nut II, 23. beam, 24. lever, 25. suspension plate, 26. weight, 27. bolt , 28. "Ten" frame in the shearing frame, 29. Pillar, 30. Roller system, 31. Roller guide rail, 32. Roller, 33. Roller bearing, 34. Ram, 35. Nut, 36. Fixing, Bolts for the lower roller guides.

5. Specific implementation

The utility model will be further described in conjunction with the accompanying drawings.

As shown in Figures 1 to 4, the portable field and indoor dual-purpose direct shear tester of the present utility model mainly includes sampling equipment (shearing frame 2 and rigid frame 3), horizontal tension and shearing system (chain 12, hand wheel 16 , tension sensor 13, etc.), mobile vertical loading system (roller system 30, beam pillar 18, beam 23, pillar 29, force transmission plate 9, force transmission column 10, lever 24, etc.) and box frame 7, rigid frame Base 4 and displacement measuring equipment (vertical displacement meter 5, horizontal displacement meter 6).

The above-mentioned shearing frame 2 is a square frame of a cross-shaped frame 28, which can make the strain of the sample in the shearing process more uniform than that without a cross-shaped shearing frame; Chain hook 11, horizontal displacement meter 6 is housed in its center, for doing the test of cohesive soil and fine sand, the net size of shearing frame 2 is: long * wide = 141mm * 141mm, height is 20mm, for doing particle diameter relatively For large soil and rock tests, its size can be appropriately enlarged; the net size of the rigid frame 3 is the same as that of the shear frame 2, and the outer four surfaces of the lower ends of the two are all knife-edge shapes, and the rigid frame 3 is placed in the rigid frame base 4 , fixed with screws 8, and the rigid frame base 4 is then fixed on the box frame 7.

The lower end of the force transmission column 10 in the above-mentioned mobile vertical loading system is fixed on the force transmission plate 9, the centers of the two are on the same vertical straight line, and the center line of the two passes through the center of the sample 1, and the force transmission plate The bottom surface size of 9 is the same as the plane size of the shearing frame 2, and the vertical displacement meter 5 is installed on the top of the force transmission plate 9, and the other end of the force transmission column 10 is connected with the lever 24 and the fulcrum end cover 20 through the lever bearing 19, and the lever The end of 24 is a hanging pan 25, the lower end of the hanging pan is a weight 26, and the pillar 29 has threads, and its lower end is screwed into the fulcrum end cover 20 li, and is fixed with the pillar nut 121, and the pillar 29 upper end is placed in the center hole of the crossbeam 23 , and can move up and down, so that the force transmission plate 9 and the force transmission column 10 can be adjusted vertically according to the needs. A crossbeam pillar 18 is supported and fixed by a nut 35. The other end of the crossbeam pillar 18 is threaded. Guide rail is fixed on the box frame 7, and the two ends of two roller guide rails 31 are fixed by the bolt 36 of fixing upper and lower roller guide rails. Roller guide rail length is 40cm, guarantees that ram 34 has the mobile displacement of 5cm thereon. The structural characteristics of such a vertical loading system are: due to the small rolling friction of the rollers, during the shearing process of the sample, the movement of the shearing frame 2 will drive the force transmission plate 9, the force transmission column 10, the lever 24, and the beam 23 , beam pillar 18, ram 34, and roller 32 move together, so that the shearing frame 2 and the vertical loading system move synchronously during the shearing process, ensuring that the vertical force will not be eccentric during the test.

In the above-mentioned horizontal tension and shear system, the chains 12 are two steel chains or steel wire ropes (replaced by chains here), each about 15 cm long, and one end of the two chains 12 is respectively connected to the chain hook 11 on the shearing frame 2 The other end of two chains is connected on one end of connector 14, and this end is the steel ring that can rotate freely; Threaded hand wheel push rod 15 is connected, and hand wheel 16 is connected with hand wheel push rod 15. Turn the handwheel 16, and the handwheel push bar 15 can advance or retreat. Handwheel 16 is identical with the handwheel of conventional indoor direct shear instrument, and it is fixed on the box frame 7 by handwheel fixing bolt 17.

The vertical displacement meter 5 and the horizontal displacement meter 6 are sensor devices. The contacts of the former are set up on the force transmission plate 9 to test the vertical displacement of the sample during the test process; the contacts of the latter are set up in the shearing direction to shear The central part of the front of the frame 2 or the central part of the front of the force transmission plate 9 in the shear direction is used to test the shear displacement of the sample during the test.

The specific implementation steps are as follows:

1. Put the soil sample containing the rigid frame 3 obtained on the spot or prepared indoors into the rigid frame base 7 fixed on the box-shaped frame 7, and tighten the rigid frame 3 with the rigid frame fixing screws 8, as shown in Fig. 1;

2. Install the lever 24 on the beam 23, and add a certain weight 26 on the suspension plate 25 according to the test pressure;

3. Install measuring equipment, set up displacement meter 5 on force transmission plate 9, and measure vertical displacement; set up displacement meter 6 on the central part of the front of shear frame 2 or force transmission plate 9, and measure shear displacement ; One end of the tension sensor 13 is connected to the handwheel push rod 15, and the other end is connected to the connector 14 to measure the horizontal tension, and the chain 12 is connected to the connector 14 and the chain hook 11;

4. Connect the displacement gauges 5, 6 and the tension sensor 13 to the data conversion box, and the data conversion box is connected to the microcomputer, set the parameters of data acquisition, shake the handwheel 16 at a certain speed, and perform shearing. Realize the automatic collection of data;

5. After the test is over, turn the pillar nut II22, lift up the overall pressurizing device including the force transmission plate 9, the force transmission column 10 and the lever 24, loosen the rigid frame fixing screw 8, and take out the rigid frame 3 and the shear frame. 2 samples;

6. Data arrangement: the normal stress σ and shear stress τ on the shear plane are calculated according to the following formula:

$\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="G"\; filenames="Y20072004038800081.png,Y20072004038800082.png"\; state="\{\{state\}\}">G</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; twenty\; four</span>}{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Among them: _G1 is the total weight of the force transmission plate 9 and the force transmission column 10, _G2 is the weight of the added weight 26, _σ1 is the pressure generated by the self-weight of the lever on the sample, and T is the level measured by the tension sensor 13 Tensile force, A is the shear surface area.

Claims (4)

1. portable field and indoor dual-purpose direct shear test instrument, comprise sampling equipment, vertical loading system, it is characterized in that it comprises that also horizontal stretch-draw cut system, wherein sampling equipment is formed with rigid frame (3) by shearing frame (2), shearing frame (2) places the top of rigid frame (3), vertical loading system is portable, wherein two crossbeam pillars (18) are fixedly connected on respectively on two rams (34) of roller system (30), pulley system is by two rolling wheel guide rails (31), two rollers (32) are embedded in the U type groove of rolling wheel guide rails (31), and roller bearing (33) is connected roller (32) with ram (34); The end that two chains (12) in the system are cut in horizontal stretch-draw is connected on the chain hook of shearing on the frame (2) (11), the other end is connected on the steel annulus of web member (14) one ends, the other end of web member (14) is by being threaded on the pulling force sensor (13), the other end of pulling force sensor (13) is connected with the handwheel catch bar (15) with screw thread, handwheel (16) is connected with handwheel catch bar (15), handwheel catch bar (15) can advance or retreat when rotating handwheel (16), and horizontal stretch-draw is cut system and is fixed on the boxed frame (7) by bolt (17).

2. portable field according to claim 1 and indoor dual-purpose direct shear test instrument, it is characterized in that the square box of described shearing frame (2) for cross (28), two chains hooks (11) are arranged on one side of shearing frame (2), its central part has set up horizontal displacement meter (6), described rigid frame (3) dead size is identical with shearing frame (2), outside four faces in the two lower end are edge of a knife shape, rigid frame (3) is placed in the rigid frame base (4), fixing with screw (8), rigid frame base (4) uses bolt (27) to be fixed on the boxed frame (7) again.

3. portable field according to claim 1 and indoor dual-purpose direct shear test instrument, the lower end that it is characterized in that the force-transmitting pole (10) in the described vertical loading system is fixed on the force transmitting board (9), the center of the two is on same vertical line, and the center line of the two is by the center of sample (1), the bed-plate dimension of force transmitting board (9) is identical with the planar dimension of shearing frame (2), vertical displacement meter (5) is equipped with on the top of force transmitting board (9), the other end of force-transmitting pole (10) is connected with fulcrum end cap (20) with lever (24) by lever bearing (19), the end of lever (24) is hanging scaffold (25), the hanging scaffold lower end is counterweight (26), pillar (29) has screw thread, its lower end snail is advance fulcrum end cap (20) lining, and it is fixing with pillar nut I (21), pillar (29) upper ends is in the center pit of crossbeam (23), and can move up and down, so just can make force transmitting board (9), force-transmitting pole (10) is adjusted height in vertical direction as required up and down, height control well after, pillar (29) is fixed on the crossbeam (23) by pillar nut II (22), crossbeam (23) is supported by two crossbeam pillars (18), and it is fixing by nut (35), crossbeam pillar (18) other end has screw thread, its spiral shell is advance ram (34) lining, ram (34) is enclosed within outside the rolling wheel guide rails (31), on rolling wheel guide rails (31) has, following two, the bottom roller guide rail is fixed on the boxed frame (7), and the two ends of two rolling wheel guide rails (31) are by on fixing, the bolt of bottom roller guide rail (36) is fixing.

4. portable field according to claim 1 and indoor dual-purpose direct shear test instrument is characterized in that the chain (12) that described horizontal stretch-draw is cut in the system is two steel link chains or wire rope, every long 15cm.

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