CN206573100U - Settling column test instrument for pore pressure distribution measuring - Google Patents
Settling column test instrument for pore pressure distribution measuring Download PDFInfo
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- CN206573100U CN206573100U CN201720168919.0U CN201720168919U CN206573100U CN 206573100 U CN206573100 U CN 206573100U CN 201720168919 U CN201720168919 U CN 201720168919U CN 206573100 U CN206573100 U CN 206573100U
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Abstract
The utility model is related to Study on foundation treatment field, it is desirable to provide a kind of settling column test instrument and test method for pore pressure distribution measuring.In the hollow cylindrical chamber for containing soil sample, vertical be provided with the drain bar being fixed on steelframe, hollow drain bar is arranged at intervals multiple vacuums probes, on the bottom plate of chamber and is uniformly distributed multiple sensor for pore water pressure on the wall of side；Each vacuum probe and sensor for pore water pressure are connected to data acquisition device by signal wire, and data acquisition device is connected with host computer；The upper end of drain bar is connected by sealing joint with drainpipe, and another be connected on vavuum pump, drainpipe of drainpipe sets vacuum meter.The utility model can monitor the pore pressure situation of change of different depth and different radial positions.It is simple in construction, be easy to left-hand seat, cast material and banket it is repeatable utilize, do not result in waste and pollute, and can record data automatically, the required human hand of experiment is reduced, while the error produced when reducing artificial reading.
Description
Technical field
The utility model is on Study on foundation treatment field, more particularly to a kind of measurement vacuum preloading discharging consolidation process
The consolidation test method that pore pressure changes at middle different radii different height.
Background technology
With the continuous propulsion of Urbanization in China and building cause, the flourishing ground of the coastal economy such as the Yangtze River Delta, Pearl River Delta
The buildings such as substantial amounts of highway, high-speed railway, airport, skyscraper and structures are built in area.However, due to ground
Manage historical reasons, these regional soil properties are generally that natural moisture content is high, natural void ratio is big, high-compressibility, hypotonicity are deep soft
Clay, this kind of soil layer low intensity, foundation bearing capacity and stability are not enough, easily caused when as ground the big sedimentation of building or
Differential settlement, makes building occur unstable failure.Therefore, these areas usually require to handle Soft Clay Foundation.
Vacuum method is first to lay sand bedding course on the soft soil foundation surface needed reinforcement, then buries vertical drain
Road, then make itself and atmospheric isolation with air-locked close membrane, diaphragm seal end carries out pile things on processing, passes through what is buried in sand bedding course
Suction piping, is vacuumized using vavuum pump or other vacuum means, forms it into negative pressure under film, increases the effective stress of ground.
Drainage by shaft wells concretion method is one of method for being most widely used in current numerous soft base processing methods, by being set in ground
Vertical drain well (such as sand drain, sand wick, plastic draining belt), and certain load mode hierarchical loading is combined, progressively
The pore water in Soft Clay Foundation is discharged, accelerates soil solidifying speed, shortens consolidation time, it is final to realize quick enhancing foundation soil
Intensity, raising foundation bearing capacity, reduction settlement after construction and differential settlement, it is ensured that the purpose of the stable safety of superstructure.Vacuum
The processing method that precompressed and vertical shaft are combined is because processing time is short, the construction low advantage of simple and safe, expense has been obtained widely
Use.But the above method is high to sticky extremely strong, water content, for the great blowing-filling sludge ground of compressibility, still suffers from one
A little problems so that treatment effeciency is not high.
Therefore, can by the vacuum change during experimental study vacuum preloading discharging consolidation and pore pressure changing rule
Studied with the detailed process to Practical Project, propose reasonable arrangement vacuum preloading process and select more suitable drain bar
Suggestion, so as to be favorably improved the efficiency of basement process.
Utility model content
The technical problems to be solved in the utility model is to overcome deficiency of the prior art there is provided one kind for pore pressure point
The settling column test instrument of cloth measurement.
To solve the above problems, solution of the present utility model is：
A kind of settling column test instrument for pore pressure distribution measuring is provided, including tried for the hollow cylindrical for containing soil sample
Tryoff and geotextiles and plastic sheeting for sealing soil sample, and for determining the sedimentation mark of soil sample sedimentation；In chamber
Vertical be provided with the drain bar being fixed on steelframe, hollow drain bar is arranged at intervals multiple vacuums probes, in chamber
On bottom plate and it is uniformly distributed multiple sensor for pore water pressure on the wall of side；Each vacuum probe and sensor for pore water pressure are connected by signal wire
To data acquisition device, data acquisition device is connected with host computer；The upper end of drain bar is connected by sealing joint with drainpipe,
Another be connected on vavuum pump, drainpipe of drainpipe sets vacuum meter.
In the utility model, the chamber is placed on bearing, and being provided between chamber bottom plate and bearing is used to adjust
The screw of chamber level.
In the utility model, the set-up mode of the sensor for pore water pressure is：An access equi-spaced apart on chamber bottom plate
Circle, a hole slot is opened up every 30 ° along circle, on the wall of chamber side fetch bar equi-spaced apart circumference, circumferentially often
A hole slot is opened up every 30 °；The sensor for pore water pressure is installed in each hole slot, and realizes sealing with sealing ring.
The method that settling leg pore pressure distribution measuring is carried out using test instrument in the utility model, is comprised the steps：
(1) soil sample is stirred, the basic physical parameters of soil sample is measured according to indoor geotechnological conventional methods；
(2) soil sample is fitted into chamber, one layer of geotextiles is laid on its surface；
(3) drain bar being fixed on steelframe is inserted vertically into specified location in chamber, the upper end of drain bar is passed through
Sealing joint connects with drainpipe, and the another of drainpipe is connected to vavuum pump；After the completion of connection, on sealing joint and drainpipe
Side re-lays second layer geotextiles, then lays two layers of plastic thin films and is sealed；
(4) sedimentation mark is respectively arranged in the center and peripheral position of Plastic film surface, for real-time amount in process of the test
Survey the settling amount of soil body surface；
(5) vavuum pump is opened to be vacuumized, when pressure value shown in sensor for pore water pressure keeps constant within a certain period of time, or
When person's sedimentation mark is maintained at a certain position and no longer declined, off-test；
(6) in whole process of the test, the survey that each sensor for pore water pressure and vacuum are popped one's head in is collected by data collecting system
Amount data are simultaneously uploaded to host computer, realize the real-time display and data summarization and analysis of measurement data.
Before being tested, hydrophobic coating is smeared on the inwall of chamber, with reduce in the native consolidation process of sample with inwall
Between friction.The soil sample height of filling keeps the maximum value stabilization of under-membrance vacuum degree to exist between 80-85mm, when vacuumizing
More than 85kPa.
Use principle of the present utility model：
By carrying out vacuum preloading processing to soil sample, and vertical drainage passage is provided, it is many that record sensor for pore water pressure is measured
Measuring point pore pressure value, data are obtained by data acquisition device, and the pore pressure changing value mapping analysis of output are obtained in consolidation process
Rule.In addition, can be studied by the specification for changing drain bar the influence of different drain bars, so as to drain bar
Type selecting makes guidance；By being classified applying vacuum pressure, the influence of load mode can be probed into, so as to vacuum pressure in engineering
Guidance is made in application.The device experiment visual result, and it is easy to left-hand seat.
The pore pressure in multiple sites in vacuum preloading drainage procedure is monitored during experiment, the generation of consolidation process is studied
Journey, can realize and the pore pressure along radius and height distribution is measured.Drain bar is fixed on steelframe, is easy to insert drain bar
In soil, while it is also ensured that drain bar does not bend do not shift vertically in process of the test.Vacuum in soil sample is directly by draining
Plate is transmitted, and shortens vacuum transmission path.
Different experiments, which can be carried out, using the utility model becomes quantity research：
Test A：The drain bar of replacing different model, which repeats the above steps, is tested, and research uses different draining slat elements
Under, the difference of silting forming process.Drain bar different model correspondence different pore size, thickness and water-flowing amount, to study different rows
The silting situation difference of water plate, so as to make guidance to drain bar type selecting in Practical Project.
Test B：The soil sample of replacing different moisture content, which repeats the above steps, is tested, and the silting for studying different soil samples is formed
Process.
Test C：Repeated the above steps and tested using different vacuum preloading load modes, instantaneous herk is respectively adopted
The mode applying vacuum pressure loaded with staged, studies the influence that different load modes are formed to silting process.
Compared with prior art, the beneficial effects of the utility model are：
(1) the utility model can monitor the pore pressure situation of change of different depth and different radial positions.
(2) the sensor for pore water pressure small volume that the utility model is selected, can reduce pore pressure measurement and consolidation process is done
Disturb.
(3) the utility model is simple in construction, be easy to left-hand seat, cast material and repeatable utilization of banketing, and does not result in waste
And pollution, and can record data automatically, human hand needed for experiment is reduced, while the error produced when reducing artificial reading.
Brief description of the drawings
Fig. 1 is each part annexation schematic diagram of the present utility model.
Fig. 2 is each part annexation schematic diagram of the present utility model (not including data acquisition device).
Fig. 3 be in Fig. 1 A-A to top plan view (being highly 80mm, be not filled with soil sample).
Fig. 4 is the sectional view (being highly 300mm) of B-B direction in Fig. 1.
Reference in figure is：1 chamber；2 sensor for pore water pressure；3 drain bars；4 vacuum meters；5 vavuum pumps；6 data are adopted
Acquisition means；7 soil samples；8 geotextiles；9 sealing joints；10 plastic sheetings；11 drainpipes；12 bearings；13 vacuums are popped one's head in；14 sink
Drop mark.
Embodiment
As Figure 1-4, settling column test instrument of the present utility model includes being used to contain the examination of the hollow cylindrical of soil sample
Tryoff 1 and geotextiles 8 and plastic sheeting 9 for sealing soil sample, and for determining the sedimentation mark 14 of soil sample sedimentation.Chamber
1 is placed on bearing 12, and the screw for Adjustment Tests case level is provided between the bottom plate and bearing 12 of chamber 1.In experiment
Vertical be provided with the drain bar 3 being fixed on steelframe, hollow drain bar 3 is arranged at intervals multiple vacuums probes 13 in case 1,
On the bottom plate of chamber 1 and it is uniformly distributed multiple sensor for pore water pressure 2 on the wall of side；Each vacuum probe 13 and sensor for pore water pressure 2 are equal
Data acquisition device 6 is connected to by signal wire, data acquisition device 6 is connected with host computer；The upper end of drain bar 3 passes through closed
Joint 9 connects with drainpipe 11, and another be connected on vavuum pump 5, drainpipe 11 of drainpipe 11 sets vacuum meter 4.
The set-up mode of sensor for pore water pressure 2 is：The circle for an equi-spaced apart of being fetched on the bottom plate of chamber 1, along circle
A hole slot is opened up every 30 °, the circumference for bar equi-spaced apart of being fetched on the side wall of chamber 1 circumferentially opens up one every 30 °
Individual hole slot；Sensor for pore water pressure 2 is installed in each hole slot, and realizes sealing with sealing ring.
The method that settling leg pore pressure distribution measuring is carried out using test instrument described in the utility model, is comprised the steps：
(1) soil sample 7 is stirred, the basic physical parameters of soil sample is measured according to indoor geotechnological conventional methods；
(2) soil sample 7 is fitted into chamber 1, one layer of geotextiles 8 is laid on its surface；
(3) drain bar 3 being fixed on steelframe is inserted vertically into specified location in chamber 1, the upper end of drain bar 3 is led to
Cross sealing joint 9 with drainpipe 11 to connect, the another of drainpipe 11 is connected to vavuum pump 5；After the completion of connection, in sealing joint 9
Second layer geotextiles 8 are re-layed with the top of drainpipe 11, two layers of plastic thin films 10 is then laid and is sealed；
(4) sedimentation mark 14 is respectively arranged in the center and peripheral position on the surface of plastic sheeting 10, for real in process of the test
When measure soil body surface settling amount；
(5) vavuum pump 5 is opened to be vacuumized, when pressure value shown in sensor for pore water pressure 2 keeps constant within a certain period of time,
Or sedimentation mark 14 is when being maintained at a certain position and no longer declining, off-test；
(6) in whole process of the test, each sensor for pore water pressure 2 and vacuum probe 13 are collected by data collecting system 6
Measurement data and be uploaded to host computer, realize the real-time display of measurement data and data summarization and analysis.
Before being tested, hydrophobic coating is smeared on the inwall of chamber, with reduce in the native consolidation process of sample with inwall
Between friction.The soil sample height of filling keeps the maximum value stabilization of under-membrance vacuum degree to exist between 80-85mm, when vacuumizing
More than 85kPa.
It should be noted that, data collecting system 6, host computer used in the utility model, and realized in host computer
The real-time display of measurement data and data summarization and the content of analysis, the routine for being electronic circuit technology and computer technology should
With.Those skilled in the art can realize that applicant repeats no more with the technical ability of its grasp completely.
Concrete application example：
Chamber 1 is open-topped cylinder, and size is：Diameter 600mm × high 1000mm, surrounding and bottom surface are to have
Machine glass material；The bottom surface of chamber 1 and lateral opening hole, for installing sensor for pore water pressure probe.The lower section of chamber 1 is provided with
Bearing, to adjust chamber level.
Method of testing：
(1) during chamber 1 is made, sensor for pore water pressure probe 2 is loaded into specified location and sealed.Cause
This, it is necessary to carry out the sealing of each face junction and the installation place of sensor for pore water pressure 2 before being tested using chamber 1
Check.Height of the chamber 1 on bearing 12 is adjusted, makes the horizontal positioned of chamber 1.It can be seen by being added water in chamber 1
Whether the graduation mark for examining the water surface and chamber 1 flushes to complete.
(2) the tail end signal wire of sensor for pore water pressure probe 2 and vacuum probe 13 is connected with data collecting system 6, so
Trial inspection is carried out to each sensor afterwards, checks whether that each sensor can effectively work.
(3) soil sample 7 fetched from scene after soil nature test be fitted into chamber 1, the filling of soil sample 2 is highly controlled
Between 0.8m to 0.85m.
(4) after soil sample 7 loads chamber 1, the steelframe for securing drain bar 3 is slowly pressed into soil.Then in soil sample
One layer of geotextiles 8 are laid on surface, are then connected using sealing joint 9 with drainpipe 11, and lay one layer of geotextiles on its surface
After re-lay two layers of plastic thin films sealing.Finally, it is with the mud of moistening that surrounding is floating, it is ensured that air tight.Finally, plastics are utilized
Foam sheet is in soil body surface arrangement sedimentation mark 14.
(5) after installation, open vavuum pump 5 and vacuumize, vacuum pressure stabilization is in 90kPa (according to specific test plan
Determine vacuum pressure value).Check whether the sealing of plastic sheeting 10 is tight, and mending-leakage measure is then taken if any gas leak phenomenon.Experiment
The continuous pumpdown time is preset as 14d (being determined according to specific test plan).Vacuumize and moisture content is carried out to soil sample 7 after end
Detection.
(6) when a period of time off-test for reaching following condition：
Pressure value shown in sensor for pore water pressure 2 keeps constant within a certain period of time, or sedimentation mark 14 is maintained at a certain position
When no longer declining.
(7) after off-test, recovery test case 1 and experiment soil sample 7, and carry out data processing.
Finally it should be noted that listed above is only specific embodiment of the utility model.Obviously, this practicality is new
Type is not limited to above example, can also there is many variations.One of ordinary skill in the art can be from disclosed in the utility model
All deformations for directly exporting or associating in content, are considered as protection domain of the present utility model.
Claims (3)
1. a kind of settling column test instrument for pore pressure distribution measuring, including for contain soil sample hollow cylindrical chamber and
Geotextiles and plastic sheeting for sealing soil sample, and for determining the sedimentation mark of soil sample sedimentation；Characterized in that, in experiment
Vertical be provided with the drain bar being fixed on steelframe, hollow drain bar is arranged at intervals multiple vacuums probes in case, in experiment
On the bottom plate of case and it is uniformly distributed multiple sensor for pore water pressure on the wall of side；Each vacuum probe and sensor for pore water pressure pass through signal wire
Data acquisition device is connected to, data acquisition device is connected with host computer；The upper end of drain bar passes through sealing joint and drainpipe
Connect, another be connected on vavuum pump, drainpipe of drainpipe sets vacuum meter.
2. test instrument according to claim 1, it is characterised in that the chamber is placed on bearing, chamber bottom plate
The screw for Adjustment Tests case level is provided between bearing.
3. test instrument according to claim 1, it is characterised in that the set-up mode of the sensor for pore water pressure is：In experiment
The circle for an equi-spaced apart of being fetched on bottom plate, a hole slot is opened up every 30 ° along circle, bar etc. of being fetched on the wall of chamber side
Circumference away from interval, circumferentially opens up a hole slot every 30 °；The sensor for pore water pressure is installed in each hole slot, and to seal
Circle realizes sealing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720168919.0U CN206573100U (en) | 2017-02-24 | 2017-02-24 | Settling column test instrument for pore pressure distribution measuring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720168919.0U CN206573100U (en) | 2017-02-24 | 2017-02-24 | Settling column test instrument for pore pressure distribution measuring |
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| CN206573100U true CN206573100U (en) | 2017-10-20 |
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| CN201720168919.0U Active CN206573100U (en) | 2017-02-24 | 2017-02-24 | Settling column test instrument for pore pressure distribution measuring |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106840087A (en) * | 2017-02-24 | 2017-06-13 | 浙江大学 | For the settling column test instrument and test method of pore pressure distribution measuring |
| CN109883851A (en) * | 2019-04-03 | 2019-06-14 | 水利部交通运输部国家能源局南京水利科学研究院 | Gas injection-vacuum consolidation testing device and test method for high-moisture percentage mud |
-
2017
- 2017-02-24 CN CN201720168919.0U patent/CN206573100U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106840087A (en) * | 2017-02-24 | 2017-06-13 | 浙江大学 | For the settling column test instrument and test method of pore pressure distribution measuring |
| CN109883851A (en) * | 2019-04-03 | 2019-06-14 | 水利部交通运输部国家能源局南京水利科学研究院 | Gas injection-vacuum consolidation testing device and test method for high-moisture percentage mud |
| CN109883851B (en) * | 2019-04-03 | 2024-04-16 | 水利部交通运输部国家能源局南京水利科学研究院 | Gas injection-vacuum consolidation test device and method for high-water-content sludge |
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