DIRECT SHEAR APPARATUS

Transcription

1 DIRECT SHEAR APPARATUS I a direct shear test, the failure of the soil sample i shear is caused alog a predetermied plae. Test is performed as per IS 2720 part XIII The ormal load, strai ad shearig force are measured directly durig the test. It is also used to estimate residual stress of soil. The apparatus utilizes a square box divided horizotally ito two halves. The box cotaiig the sample is placed i a water jacket ad subjected to costat ormal load while a horizotal force is applied till the specime fails alog the plae of jucture of the two halves. A umber of specimes are tested uder differet loads ad from the data obtaied the agle of iteral frictio ad shearig stregth of the soil ca be evaluated. Followig pages give details of both had operated ad motorised versios of direct shear test apparatus coformig to differet Idia Stadard Specificatios. Complete as above but without dial gauges ad provig rig. HS Direct Shear Apparatus, 12 speed, Motorised IS : 2720 (Part XIII) IS:11229 The uit is same as HS24.05 except that it is motorised. It is provided with a turret type gear box to get 12 differet costat rates of strai i.e 1.25, 0.625, 0.25, 0.125, 0.05, 0.025, 0.01, 0.005, 0.002, 0.001, , ad mm/mi. ad arragemets to carry out residual shear stregth tests. Suitable for operatio with 220V, 50 hz, sigle-phase supply. OPTIONAL ACCESSORIES: HS30.15 Provig Rig (Itegral) capacity 200 kg (2 kn) (Tesio/Compressio) Note: Tesio- compressio provig rig ad dial gauge required for carryig out residual shear stregth tests, does ot form a part of the stadard outfit ad has to be ordered separately. HS24.05 Direct Shear Apparatus, Had Operated IS : 2720 (Part XIII) The uit cofirms to IS2720. It has a had operated horizotal loadig system for shearig the specime. Hagers are provided for creatig ormal stress. It comprises :- i) Shear box assembly, 60 mm square, complete with a U-bracket, guide pis ad spacig screws, made of brass. ii) Gripper assembly cosistig of two plai grid plates, two perforated grid plates, oe base plate ad oe loadig pad, all made of brass. iii) Two porous stoes, each 6 mm thick, fittig the shear box iv) Shear box housig of brass, complete with two ball roller strips. v) Loadig uit with ormal loadig of 8 kg/cm 2 o 60 mm square specime. vi) Specime cutter for a specime size of 60 mm x 60 mm x 25 mm. vii) Set of weights to give a ormal stress upto 3 kg/cm 2 through lever, comprisig 4 of 0.05 kg/cm 2, 1 of 0.1 kg/cm 2, 1 of 0.2 kg/cm 2, 3 of 0.5 kg/cm 2 ad 1 of 1 kg/cm 2. HS29.15 Dial Gauge 0.01 mm x 25 mm rage for measurig strai ad cosolidatio. (Two gauges are required). S-24 HS24.15

2 HS Electroic Direct Shear Apparatus, 12 Speed, Motorised with Microprocessor Based electroic uit, As per IS:2720 (Part-XXXIX/Sec-1) The uit is same as HS except that the trasducers like displacemet sesors ad load cell with micro-processor display system are provided istead of dial gauges ad provig rigs. Total loadig capacity of the apparatus is 8 kg/cm 2. It is provided with stadard 60mm shear box assembly. Set of weights to give a ormal stress up to 3 kg/cm 2 o the specime through lever is provided as stadard. Additioal weights are to be ordered separately. Electroic System Load cell uiversal (uiversal)2kn - 1 No. LVDT + 20 mm Digital display /coditioig uit - 2 No. The Three-chael micro processor based sigal coditioig uit is the three-fuctio system. The fuctios are load, horizotal displacemet ad vertical displacemet directly idicated i their respective egieerig uits. The system receives the output sigal from the sesors i.e. Load cell ad Displacemet Sesors attached to the Direct shear Test apparatus. It cosists of the power supply, sigal coditioig cards ad processig card. The sigal-coditioig card amplifies the sigal of each sesor ad trasfers it to processig card. The processig card cosists of a Micro cotroller that stores the readig of each sesor ad fially trasfers it to computer. The data of all three chaels of Direct Shear Test ca be trasferred to computer ad ca be moitored olie. The Uit also provides the facility of olie moitorig of data through LCD display. Broadly the followig facilities are icorporated i the system:- i) Three idepedet chaels. Load (N), Horizotal Displacemet(mm), Vertical Displacemet (mm) ii) Idepedet display for each chael simultaeously. iii) Prit iterval / data trasfer iterval is programmable (betwee 10 secod to 1 hour) iv) Automatic data savig o stop butto. v) 25 set of results ca be stored i the electroic uit.. Sample umber ca be programmed vi) Olie date ad time of test is stored vii) alog with the data. O lie (while the test is i progress) data trasfer to the computer which is stored i the computer with a particular file ame ( through RS232). Data ca be dowloaded to the computer after the test, which is stored eve after the power is off. viii) Without computer, test data ca be prited through priter port provided i the electroic uit. (Computer is ot part of the system) Optioal Accessories (1) Software i) O-Lie Data Acquisitio Software ii) O-Lie Data Trasmissio from Sigal Coditioig Uit to Computer iii) Off-Lie Data Aalysis Software that does all the calculatios of Direct Shear Test. iv) Has optio for maual as well as automatic recordig of data. v) Calculates Area, Volume, Bulk desity, Dry desity, Moisture cotet etc. of the specime vi) Display the followig Plots. a Horizotal Displacemet vs Shear Force b Horizotal Displacemet vs Vertical Displacemet c Normal stress vs Shear Force d Maximum value of the Dilatio Agle The software is widows based ad user friedly. It is easy to operate ad has the flexibility to eter differet sizes of test specime up to 1000mm x 1000mm. S-25 HS

3 (2) Computer Note : The computer with latest cofiguratio will be supplied. HS Direct/Residual Shear Test Apparatus(Cofirmig to IS2720 Part XXXIX ad BS1370) A automatic system eables performig of Direct Shear adresidual Shear tests through a total computer cotrol. It is a table-mouted model ad has stepper motors cotrollig shearig load. Stress levels ca be maitaied with i the limits of +0.5% through set of weights. Vertical ad horizotal displacemets ad shearig load are all displayed i their respective egieerig uits o LCD display. Board specificatio of the uit are:- 1) Rate of strai: mm/mi 2)Load rage capacity : +5 kn HS Computer Cotrolled Direct Shear Apparatus Coformig to IS: 2720 (Part XIII) & BS 1377 HS The uit is totally computer cotrolled, it has 2 servo motors, oe for shear load ad the secod for maitaiig ormal load. Circuit for ormal load is based o closed loop pricipal. Electroic Sesors The uit icludes :- 1 Load cell Uiversal type : 2 Displacemet sesor horizotal : 3 Displacemet sesor vertical : 2000N + 20mm + 20mm Supplied complete with weight upto 3kg/cm 2 COMPUTER Dedicated Computer with Data Acquisitio card with latest cofiguratio will be supplied. S-26 HS

4 Saliet Features Eables Direct shear tests through a total computer cotrolled operatio Coforms the test requiremet of IS (Part-XIII) & BS 1377 Programmable Normal stress from 0.01N/mm2 to 0.5N/ mm2 ad maitai Stress level with i the limit of + 0.5% Strai rate programmable form mm/mi mm/mi. Shear box suitable for 60x60 mm sample (Optioal 100x100mm sample) Olie plottig of Load vs Displacemet, Load vs Time ad Displacemet vs Time curves ad display of data for all the chaels Advaced Aalysis Software The complete System cosists of the follow- ig:- i) Shear Box Assembly ii) iii) iv) Loadig Frame Shear box assembly, 60 mm square, complete with a U-bracket, guide pis ad spacig screws, made of brass Gripper assembly cosistig of two plai grid plates, two perforated grid plates, oe base plate ad oe loadig pad, all made of brass v) Two porous stoes 6 mm thick, fittig the shear box vi) vii) Shear box housig of brass, complete with two roller strips Specime cutter for the specime viii) PC based Cotrol system ad Cotrol Software a. Sigal Coditioig ad Cotrollig Uit with Trasducers b. Dedicated Computer for cotrollig ad Data acquisitio c. Cotrol & Aalysis software Loadig Frame Rate of strai : mm/mi Shearig Load capacity : N Displacemet rage : +20mm Normal stress rage : 0.01N/mm2 0.5N/ mm2 PC BAESD CONTROL SYSTEM AND CONTROL SOFTWARE Cotrol system provides the digital cotrol of the motors to apply ormal stress ad shearig load, data acquisitio etc. for the cotiuous operatio of the system. a. Sigal Coditioig ad Cotrol Uit with Trasducers The four-chael sigal coditioig ad cotrol uit has drive cards that cotrols the operatio of the two motors idepedetly to set the ormal stress ad shearig strai. Sigal coditioig uit also receives the output sigal from the various trasducers (Load cells ad Displacemet Trasducers) ad amplifies ad process that sigal as per the requiremet ad trasfer it to computer through coectig cables where it is accepted by the data acquisitio system. The readigs of Shearig Load, Normal stress, Horizotal ad Vertical Displacemet are directly idicated i the computerized display. The Load is displayed i terms of N with a resolutio of 1.0N, Normal stress i N/mm2 with resolutio of 0.01 N/mm2, Horizotal Displacemet ad Vertical Displacemet i terms of mm with a resolutio of 0.01mm each. Three aalog output voltage poits for each chael with groud is also provided i the uit. Trasducers Specificatio: - 1 Load Cell Capacity : 2000N 2. Liear Variable Differetial Trasformer (LVDT) Type (2 No.s):- Stroke : ± 20mm b. Dedicated Computer for cotrollig ad Data acquisitio System is provided with dedicated computer with built i data acquisitio card. Broad specificatio of the computer ad the data acquisitio card is give below. (Note- Latest available model of the computer will be supplied at the time of delivery) c. Cotrol ad Aalysis Software Cotrol software is the itegral part of the system for precise cotrollig & Data Acquisitio ad aalysis. Saliet Features- Widows based user friedly software Programmable Rate of shearig ad Normal stress O-Lie Data Acquisitio from Sigal Coditioig Uit to Computer Computer/Software programmable Safety Limits for each load & displacemet Idepedet Tarig of each chael Facility to Load ad Uload the specime at specified rate Facility to hold the shearig loadig ad restart the loadig durig the test. Facility for Ichig ad release for adjustmet of the gap O-Lie Data Acquisitio from Sigal Coditioig Uit to Computer S-27

5 O-lie display of readigs of Shearig Load, Normal stress, Horizotal ad Vertical Displacemet O-lie display of Shear Load v/s Horizotal Displacemet & Vertical Displacemet v/s Horizotal Displacemet graphs Auto adjustmet of graph scales Calculatios of various parameters Facility to save the data after the test Aalysis Software Off-Lie Data Aalysis Software that does all the calculatios of Direct Shear Test as per IS:2720 Part VIII. HS24.20 Direct Shear Apparatus, Large, Motorised IS: 2720 (Part XXXIX/Sec. I) This is required for testig 300 mm x 300 mm x 150 mm soil sample cotaiig gravel with particle size more tha 4.75 mm. Has optio for maual as well as automatic recordig of data. Calculates Area, Volume, Bulk desity, Dry desity, Moisture cotet etc. of the specime Display the followig Plots (Graphical) (a) (b) (c) (d) Horizotal Displacemet vs Shear Force Horizotal Displacemet vs Vertical Displacemet Normal stress vs Shear Force Maximum value of the Dilatio Agle HS Optioal 100mm shear box assembly complete with porous stoe ad gripper plate. S-28

6 The uit provides 72 differet costat rates of strai for shear load ragig from mm/mi. to mm/mi ad is suitable for carryig out residual shear stregth test. The equipmet comprises of the followig :- i) Loadig Uit havig a ormal load capacity of 3 kg/cm 2 through lever ad shearig load capacity upto 5000 kg maximum. ii) Shear box assembly i two halves, complete with two guide pis ad three spacig screws. iii) Shear box housig, complete with two ball roller strips. iv) Two perforated gripper plates. v) Two plai gripper plates. vi) Two plai grid plates, oe for top ad oe for bottom. vii) Two perforated grid plates oe for top ad oe bottom. viii) Oe base plate. ix) Oe loadig pad with liftig hadles. x) Oe set of slotted weights to give a maximum ormal stress itesity of 3 kg/cm 2 o the specime through lever system. Suitable for operatio o 220 V, 50 Hz, sigle phase supply. Supplied without Provig Rig ad dial gauges which are to be ordered separately. ACCESSORIES & SPARES: HS29.15 Dial Gauge 0.01 x 25 mm for cosolidatio measuremet. HS29.20 Dial Gauge 0.01 x 50 mm for horizotal strai measuremet. HS kg Provig Rig for shear load measuremet. HS kg Provig Rig for shear load measuremet. HS Perforated gripper plates set of two. HS Plai Gripper plates set of two. HS Grid plates plai set of two. HS Grid plates perforated set of two. HS Electroic Direct Shear Apparatus, Large, Motorised IS: 2720 (Part XXXIX/Sec. I) Same as HS24.20 except that the uit is provided with electroic digital system & sesors for vertical displacemet, & horizotal displacemet & load cell for shearig load. Broad specificatio of digital display uit is give below. Sesor Displacemet sesors +50mm Load Cell 30kN Digital display system with RS232-1 No HS Digital Direct Shear Apparatus S-29-2 Nos. -1 No This uit is similar to HS except that it ca accommodate sample size of 300*300*150 mm. Servomotor ca create power to give a shearig load of 50kN. Additioal Stepper motor is provided for ormal stress. This stepper motor ca create a maximum stess of 5kg/sqcm. Total cotrollig is through the computer. Parameters like shearig load, vertical strai ad horizotal strai is show o the moitor. Operatio is based o the close loop Priciple the specime to be sheared ca be loaded either o strai basis or stress basis. Selectio of this mode has to be made at the begiig of the test. Maximum strai rate that ca be achieved is mm/mi where as the miimum strai rate could be programmed as low as mm/mi. Loadig System For Horizotal strai cotrolled through micro stepper motor: i) Rate of strai : mm/mi. ii) Load rage capacity : + 50kN iii) Displacemet rage : +50mm For Vertical Cosolidatio: i) Capacity : 5kg/cm 2 ii) Rage : 0-20 mm Electroic Sesors i) Load cell ii) Uiversal type : 50kN iii) Displacemet sesor horizotal : +50mm iv) Displacemet sesor vertical : +50mm Saliet Features of software ad graphical plots i) It is supported by user-friedly widows based software for graphical plottig ad umerical tabulatios. ii) Horizotal displacemet vs. Vertical displacemet iii) iv) Normal stress vs. Shear stress Displays maximum value of dilatio agle alog with c ad ø values. HS