CN102221387B - Pressure plate instrument capable of directly measuring volume change of soil sample - Google Patents

Abstract

Translated fromChinese

一种可直接测定土样体积变化的压力板仪装置，本发明是由压力容器、水平位移传感器、垂直位移传感器、位移传感器支架、高进气值陶瓷板、底座、土样、排水体积量测装置，以及压力容器上盖组成。土样的排水体积可以由排水体积量测装置量测，安装在位移传感器支架上水平位移传感器和垂直位移传感器可以量测土样在试验过程中的水平向和垂直向的变形，通过土样水平向和垂直向的变形值即可准确计算出土样的体积和体积应变。

A pressure plate instrument device that can directly measure the volume change of a soil sample. The invention is composed of a pressure vessel, a horizontal displacement sensor, a vertical displacement sensor, a displacement sensor bracket, a ceramic plate with a high air intake value, a base, a soil sample, and a drainage volume measurement device. device, and the upper cover of the pressure vessel. The drainage volume of the soil sample can be measured by the drainage volume measurement device. The horizontal displacement sensor and the vertical displacement sensor installed on the displacement sensor bracket can measure the horizontal and vertical deformation of the soil sample during the test. The volume and volume strain of the soil sample can be accurately calculated based on the deformation values in the vertical and vertical directions.

Description

A kind of pressure plate apparatus that can directly measure the soil sample volume change

Technical field

The present invention relates to a kind of pressure plate apparatus device that can directly measure the soil sample volume change in the Soil Mechanics and Foundations foundation works.

Background technology

Soil-the water characteristic curve of soil claims again water characteristic curve, is the matric suction of unsaturated soil and the relation curve between gravity water cut, volumetric(al) moisture content, saturation degree or the effective saturation.Soil-water characteristic curve is with factor analysis such as the composition of the structure of soil, soil particle, pore size distribution, has reflected the hold ability of soil to moisture, and it is playing the part of important role in the research of unsaturated soil mechanics.Can determine the intensity of unsaturated soil according to soil-water characteristic curve, calculate body strain and the infiltration coefficient of unsaturated soil, can also be in order to estimate the above moisture distribution situation of ground water level.At present, the instrument of measuring the soil-water characteristic curve of soil both at home and abroad generally all is to adopt with Tempe instrument or volumetric pressure plate instrument, but these two kinds of instruments can not be measured the volume change that soil sample occurs with the increase of suction in the process of soil-water characteristic curve of measuring soil sample, it generally is the initial volume with soil sample when calculating the volumetric water content of soil sample, but the error ratio of volumetric water content of calculating like this gained is larger, and this error increases along with the increase of soil sample drawdown deformation; In order to reduce the error in this calculating as far as possible, someone adopts the measured volume change of shrinkage test to revise the volumetric water content of soil-water characteristic curve, but the boundary condition of soil sample in Tempe instrument or volumetric pressure plate instrument, there is very big-difference in the situation of soil sample in stress state and stress path and the shrinkage test, the distortion of soil sample is different with body strain in two kinds of tests, therefore, also there is significant limitation in the volumetric water content that adopts the measured volume change of shrinkage test to revise soil-water characteristic curve, and this problem does not also have good solution at present.

Summary of the invention

The volumetric pressure plate instrument of soil-water characteristic curve of solving present mensuration soil sample the objective of the invention is: for can not be measured the volume change that soil sample occurs with the increase of suction in process of the test, thereby can not accurately calculate the deficiency of soil sample volumetric water content, the invention provides a kind of volumetric pressure plate instrument apparatus that can directly measure the soil sample volume change, can measure easily the volume change of soil sample in process of the test, can accurately calculate volume change and the strain of soil sample in the different suction situations, and volumetric water content, so that the test determination result is more accurate.

For achieving the above object, the volumetric pressure plate instrument apparatus that the present invention can directly measure the soil sample volume change is comprised of pressure vessel, pressure vessel loam cake, high air-entry value ceramic wafer, horizontal displacement sensors, perpendicular displacement sensor, sensor wire, displacement sensor bracket, base; Base is provided with groove and the spiral slot that high air-entry value ceramic wafer is installed, and is connected with the displacement of volume measuring equipment by pipeline; Horizontal displacement sensors, perpendicular displacement sensor are installed on the displacement sensor bracket, and displacement sensor bracket can be installed on the base, and is placed in the pressure vessel together.

At first be that one of processing can be satisfied accommodating base, soil sample, horizontal displacement sensors, perpendicular displacement sensor, displacement sensor bracket, and with the pressure vessel of sealable sensor cable hole, osculum, air admission hole, osculum, drainpipe can be by the sealings of connecting hose connection and assurance and pressure vessel binding site.The size of pressure vessel is determined according to size and the testing requirements of soil sample, can change at base the high air-entry value ceramic wafer of different size according to the requirement of the character of soil sample and test, the range of horizontal displacement sensors and perpendicular displacement sensor and precision are determined according to the requirement of test.

High air-entry valueceramic wafer 11 is installed on thebase 12 in apparatus of the present invention, there isspiral slot 13 to link to each other withosculum 14 on thebase 12,osculum 14 is connected withdrainpipe 16 by scupper hose 15,drainpipe 16 is connected with displacement ofvolume measuring equipment 19 again,soil sample 6 is placed on the high air-entry valueceramic wafer 11, and the volume thatsoil sample 6 is discharged water just can be measured by displacement ofvolume measuring equipment 19;Displacement sensor bracket 9 is fixed on thebase 12,horizontal displacement sensors 7 andperpendicular displacement sensor 8 are installed on thedisplacement sensor bracket 9, the level thathorizontal displacement sensors 7 andperpendicular displacement sensor 8 can measuresoil sample 6 to vertical to distortion, bysoil sample 6 levels to vertical to deformation values just can calculate volume and the volume change of soil sample 6.Thereby realized easily measuring in the process of the test purpose of soil sample volume and volume change.

Description of drawings

Fig. 1 is a kind of pressure plate apparatus installation drawing that can directly measure the soil sample volume change.

Fig. 2 is base and the displacement sensor bracket planimetric map of cylindrical pressure vessel.

Fig. 3 is the A-A sectional view of Fig. 2.

As shown in the figure: pressure vessel 1, pressure vessel loam cake 2, bolt 3, pressure vessel loam cake handle 4, O-ring seals 5,soil sample 6,horizontal displacement sensors 7,perpendicular displacement sensor 8,displacement sensor bracket 9,sensor cable 10, high air-entry valueceramic wafer 11,base 12,spiral slot 13,osculum 14, connecting hose 15,drainpipe 16, sensor cable hole 17,air admission hole 18, displacement of volumemeasuring equipment 19.

Embodiment

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.Fig. 1 is the pressure plate apparatus installation drawing that can directly measure volume change that the present invention adopts the cylinder type pressure vessel, before testing, first usedsoil sample 6 is carried out suitable processing and necessary Physical And Mechanical Indexes of The Typical mensuration.

When need measuring the soil of soil sample 6-water characteristic curve, elder generation is according to character and the testing requirements ofsoil sample 6, select high air-entry valueceramic wafer 11 and suitablehorizontal displacement sensors 7, theperpendicular displacement sensor 8 of range of appropriate size, high air-entry valueceramic wafer 11 is installed atbase 12, saturated by suitable method, then put into pressure vessel 1, with connecting hose 15osculum 14 on thebase 12 anddrainpipe 16 are connected,drainpipe 16 and displacement ofvolume measuring equipment 19 connect.Soil sample 6 is placed on the high air-entry valueceramic wafer 11 successively again,displacement sensor bracket 9 is fixed on thebase 12,horizontal displacement sensors 7 andperpendicular displacement sensor 8 are installed on thedisplacement sensor bracket 9, the method of taking to suit make level thathorizontal displacement sensors 7 andperpendicular displacement sensor 8 can measuresoil sample 6 to vertical to distortion, sealing is drawn and guaranteed todisplacement transducer cable 10 from sensor cable hole 17.After being ready to, by pressure vessel loam cake handle 4 pressure vessel loam cake 2 is placed on the pressure vessel 1, and between pressure vessel 1 and pressure vessel loam cake 2, place O-ring seals 5, with bolt 3 pressure vessel 1 is connected connection closely with the pressure vessel loam cake again, in case leak-stopping gas.

Read the initial volume value of draining by displacement ofvolume measuring equipment 19, the initial reading of recordinglevel displacement transducer 7 andperpendicular displacement sensor 8.

Byair admission hole 18, progressively in pressure vessel 1, apply air pressure stage by stage according to predetermined testing program, measure simultaneously the displacement of volume ofsoil sample 6 by displacement ofvolume measuring equipment 19, measuresoil samples 6 in the distortion of horizontal and vertical direction byhorizontal displacement sensors 7 andperpendicular displacement sensor 8, bysoil sample 6 levels to vertical to distortion just can calculate volume and the volume change ofsoil sample 6.

The pressure plate apparatus device that the present invention can directly measure volume change can realize directly recording the volume size ofsoil sample 6 in the process of measuring soil-water characteristic curve, thereby realized volume and the bulk strain ofsoil sample 6 in the Obtaining Accurate process of the test, made the soil-water characteristic curve that records more realistic.And simple in structure, easy to operate.

Claims (4)

1. the pressure plate apparatus that can directly measure the soil sample volume change mainly is comprised of pressure vessel, horizontal displacement sensors, perpendicular displacement sensor, displacement sensor bracket, high air-entry value ceramic wafer, base, soil sample, displacement of volume measuring equipment, pressure vessel loam cake; It is characterized in that high air-entry value ceramic wafer (11) is installed on the base (12), there is spiral slot (13) to link to each other with osculum (14) on the base (12), osculum (14) is connected with drainpipe (16) by scupper hose (15), drainpipe (16) is connected with displacement of volume measuring equipment (19) again, soil sample (6) is placed on the high air-entry value ceramic wafer (11), and the volume that soil sample (6) is discharged water just can be measured by displacement of volume measuring equipment (19); Displacement sensor bracket (9) is fixed on the base (12), horizontal displacement sensors (7) and perpendicular displacement sensor (8) are installed on the displacement sensor bracket (9), the level that horizontal displacement sensors (7) and perpendicular displacement sensor (8) can measure soil sample (6) to vertical to distortion, by soil sample (6) level to vertical to deformation values just can calculate volume and the volume change of soil sample (6).

2. a kind of pressure plate apparatus that can directly measure the soil sample volume change according to claim 1, it is characterized in that displacement sensor bracket (9), horizontal displacement sensors (7) and perpendicular displacement sensor (8) can dismounting, and can be according to adjusted size horizontal displacement sensors (7) and the position of perpendicular displacement sensor (8) on displacement sensor bracket (9) of soil sample (6).

3. a kind of pressure plate apparatus that can directly measure the soil sample volume change according to claim 1 is characterized in that changing according to the size of soil sample (6) and testing requirements horizontal displacement sensors (7) and the perpendicular displacement sensor (8) of different ranges and precision.

4. a kind of pressure plate apparatus that can directly measure the soil sample volume change according to claim 1 is characterized in that the high air-entry value ceramic wafer (11) that can change different size according to character and the testing requirements of soil sample (6).

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