Dual-purpose instrument

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Dual-purpose instrument5.Application method one :piezocone testPreparations before the test⑴. Land leveling: Clear the sundries that impede penetration .⑵. Anchoring: according to stratigraphy and the requirement of text depth, you can decide to anchor two or four anchors . And in accordance with holes, setting the next anchor point, and then two persons can anchor rota-tingly with a anchor tool (as shown in figure 25) and the extended moving rod . Stop anchoring when the anchor head off the ground is about 30 cm. According to the above method , anchor two or four ground anchors.⑶. Installing the host: fix the panel under the rack (as shown in figure 19) and the base with bolts to make a machine , then carry it to the test holes . At this time you should pad two planks under the supporting foot , and then put the beam in the anchor head with the ground anchor nut, so that the host with the anchor is a whole piece. Then make the host perpendicular to the ground with the horizontal ruler calibrated.⑷. Connecting the probe rod: The first use of a new machine, shielded cable is required to be throughout each probe, and the first end of the cable is set into the adjustable joints, and then install the probe .⑸. Outlet works in a waterproof and sealed situation, as the sealing is reliable, you can make the probe rod, the variable diameter connectedwith the probe.⑹. At the other end of the cable, check the probe's bridge circuit ( the resistance of our company’s probe bridge circuit is about 350v ), if normal, then connect the cable to the recording instrument. Then turn on the power switch, adjust the instrument to zero state, and carry out the penetration and test.Penetration and Pullout⑺. When penetrating, the probe rod and the probe must be together through the penetration hole of the host’s up per and lower panel into the holes in the soil. After insertion, guide tile (as shown in figure 3) in the upper and lower plate is lined residential the probe rod, and the clamping plate is inserted into the probe rod joint tenon, the dowel plate is placed on pallets above, shaking hands, the probe rod would penetrate to the underground .When penetrating , shake should be in consistent uniform , about 60 revolutions per minute is appropriate.⑻. During the penetration process, watching the depth gauge, generally every 10cm or 20cm, the sensing instrument displays that numerical record was read. When to certain penetration depth, slightly improved, so that the probe is in a unstressed state, check the probe zero state(checking the probe zero status shall be recorded in order to correct it if necessary.)⑼. When penetrating, the anchor uplifting shall promptly hang tight,and adjust the support legs, so that the host and the probe maintain the vertical penetration.⑽. To a predetermined depth of penetration, it should pull out the probe as soon as possible, the long delay will cause the resistance of the soil holding fast to the probe double, having difficulties in pulling the probe rod. When pulling, shake handle reversely. For fast pulling, you need to make the wave into the party tenon at the upper gear shaft of the frame,which can improve the speed to 4m/min .⑾. All the probe rod pulled out from the soil should be timely cleaned. Weigh anchoring in reversion with anchor tool , when all anchors are pulling out, this piezocone test is completed.5. Application method two: Vane Shear Test⑴. The methods of vane shear test’s anchorage, installation of the main machine, connecting of probe rod joints are same with the preparatory operating procedure of piezocone test(CPTU).⑵. After the preparatory operating procedure finished, insert the four arm braces which are under the vane’s torque case to the bore in the machine board. Make sure that the core hole on the torque case is aligned with the cross hole on the board.⑶. Methods of vane shear test’s probe head penetration and piezocone penetration. When the penetration reaches the predetermined depth, screw down the two bolts on the torque case so that the slips canfirmly hold the probe. Then adjust the meter to zero and take it as normal. Thus the test is available.⑷. When the test is being carried, turn the torque case’s handle anticlockwise at an uniform speed of 1 circle every 10 seconds. Read and record the meter’s number every circle.⑸. When the figure reaches peak or stable, go on recording another minute(that is another 6 circle). Normal figures indicate the completion of the test.⑹. When carrying on the test of remoulded soil’s shear strength, unscrew the two bolts upon the torque case and disentwine the slip and probe rod. Then clamp the probe rod with a wrench or pincer and rotate the probe rod clockwise so that the soil around the vane can be mixed thoroughly. Then screw down the two bolts quickly and the slip hold the probe rod firmly again. Repeat step 4 and step 5, the records will be the remoulded soil’s shear strength.⑺. Calculate soil’s shear strength and sensibility.Cu=10.K Ʃ RyCu’=10K Ʃ ReSt=Cu’/CuIn the formular: Cu——Shear Strength of Undisturbed SoilCu’——Shear Strength of Remoulded SoilK——50*100*2vane head 0.00218cm75*150*3vane head 0.000647cmƩ——Sensor Calibration Coefficient N.Cm/uƩRy. Re——the reading when remoulded soil and undisturbed soil at shearing state (u Ʃ)St=Soil’s SensibilityNotice: the above-mentioned figures are recorded by strain gauge. If a testing apparatus or microcomputer is chosen, you need to calibrate the probe head in advance and obtain the parameter. When using the parameter, input it into testing apparatus or microcomputer, the figure you get is Cu and Cu’.Equipment Maintenance⑴. Check the abrasion of wheel gear, chain, chain wheel, probe head, probe rod and so on. Replace them if cracking or severe abrasion are found.⑵. Clean every assembly unit and oil wheel gear, chain, chain wheel, probe head and probe screw thread in case of rust.⑶. Detach the conical tip and friction drum of probe head. Clean and oil them and place them in the dry. Remember to avoid strike, hot sun and humidity.⑷. The record instrument should be protect strictly by specially-assigned person. Charge every lying period or take out the battery in case of erosion and unnecessary damage.⑸. All of the parts of the equipment should be place in dry place and avoid rain, humidity and shock.。