CN101598658B

CN101598658B - Servo-control earth-rockfill mixture transformation permeameter

Info

Publication number: CN101598658B
Application number: CN2009100851756A
Authority: CN
Inventors: 李晓; 赫建明; 李守定; 顾金略
Original assignee: Institute of Geology and Geophysics of CAS
Current assignee: Institute of Geology and Geophysics of CAS
Priority date: 2009-05-27
Filing date: 2009-05-27
Publication date: 2011-08-17
Anticipated expiration: 2029-05-27
Also published as: CN101598658A

Abstract

The invention provides a servo-control earth-rockfill mixture transformation permeameter, comprising an upper end cap, a permeating barrel, a porous disc, a lower end cap, a trolley, a servo water-adding device and a pressure-measuring device; wherein, the upper end cap and the permeating barrel can be sealed and detached; the middle of the upper end cap is provided with a water-injecting pressure pipe which can be used for adding high pressure water after being connected with the servo water-adding device; the two sides of the cylinder permeating barrel are provided with 6 water pressure measuring devices with the same interval consisting of a three-way pipe, a pressure measuring pipe for measuring low water pressure and a water pressure gauge for measuring high water pressure; water can enter into a water catchment empty chamber through the porous disc and flows out from a water outlet; the water outlet can control the water discharging speed by be connected with a water discharge switch. By using the structure, the servo-control earth-rockfill mixture transformation permeameter has the advantages that: the sample is a cylinder with the diameter being 300mm and the height being about 600mm and is earth-rockfill mixture comprising coarse grained rock and earth; water can be added in a sealed servo manner, and the water entering speed and pressure can be servo controlled, thus finishing the permeating tests of both low water head and high water head; the upper part and the lower part of the permeameter can be detached, thus realizing safe, simple and convenient use.

Description

Servo-control earth-rockfill mixture transformation permeameter

Technical field ground permeability test technique field

Background technology is in Geological Engineering, and the Quaternary period, loose accumulation body was a kind of soil body of extensively existence and the potpourri of piece stone, and its material is formed based on gravel, piece stone and sand, clay etc.For this since naturally the accumulation formed soil-rock mixture, the rock particles size is bigger, the existing conventional permeameter can't satisfy " earthwork test rule " (SL237-1999) in the permeameter internal diameter should be test material maximum particle diameter 8-10 requirement doubly, and mostly existing permeameter is the normal pressure hydrohead test, can't satisfy the permeability test requirement of soil-rock mixture sample with high hydraulic pressure.

Summary of the invention the invention provides a kind of servo-control earth-rockfill mixture transformation permeameter, it is characterized in that to carry out soil-rock mixture large scale cylinder sample (diameter 300mm, high 600mm) seepage tests, servocontrol seepage flow hydraulic pressure obtains sample permeability parameters under high hydraulic pressure.

Servo-control earth-rockfill mixture transformation permeameter comprises upper end cover 4, infiltration tube 7, porous disc 8, bottom end cover 10, dolly 11.Upper end cover 4 is salable detachable with infiltration tube 7, has water filling forcing pipe 5 to connect servo priming apparatus 16 in the middle of the upper end cover 4 and can increase setting-out, venting when air release 6 is convenient to seal; Infiltration 7 both sides equidistant (200mm) connect 6 and survey hydraulic devices, comprise three-way pipe 2, the low hydraulic pressure of clear plastic piezometric tube 15 surveys, scaleplate 1 reading, the high hydraulic pressure of water pressure gauge 3 surveys; Water enters the sky chamber of catchmenting by porous disc 8, and water delivering orifice 13 is taken over control taps, controls out water speed; Also can pressurize by water filling forcing pipe 14 to the sample water filling; Permeameter is by flange 9 and O-ring seal 12 sealings.

Servo-control earth-rockfill mixture transformation permeameter has following characteristics: sample is the right cylinder of diameter 300mm, highly about 600mm, mostly is the soil-rock mixture that is become with local soil type by coarse grained stone; Seal servo water supply, can carry out the permeability test of low water head, also can carry out the permeability test of high water head, test head scope 0m～200m; All detachable, easy to use up and down.

Description of drawings

Accompanying drawing is the servo-control earth-rockfill mixture transformation permeameter structural drawing

1: scaleplate; 2: three-way pipe; 3: water pressure gauge; 4: upper end cover; 5: the water filling forcing pipe (on); 6: air release; 7: the infiltration tube; 8: porous disc; 9: flange; 10: bottom end cover; 11: dolly; 12: O-ring seal; 13: water delivering orifice; 14: water filling forcing pipe (descending); 15: piezometric tube; 16: servo priming apparatus

The preparation of embodiment 1. experiment materials specifically comprises evengranular coarse grain stone and each about 80kg of soil, filter screen, filter paper, graduated cylinder is arranged in addition, hit solid wood hammer, spanner etc.

2. the preparation of sample at first can be calculated the soil that needs respectively and the quality of stone according to the mass ratio of gross mass (about 120kg), soil and the stone of sample, and the quality and the mix of good soil of weighing and stone are even.Spread filter paper and filter screen in the permeameter bottom then; Connect servo priming apparatus 16 with aqueduct from permeameter bottom pressure water injection pipe 14, so that add the water stratification saturated sample; Open upper end cover 4, add soil-rock mixture from permeameter top, every layer of about 10cm is thick, evenly hit reality with wooden mallet, add water by servo priming apparatus 16 again, the control water intake velocity, make sample saturated gradually, then add down one deck again and hit real saturatedly, so successively add sample, up to upwards surpassing the about 5cm of uppermost pressure tap.Seal pressurization after above-mentioned steps is finished, the screw of tightening upper end cover 4 seals it by flange; Unscrew air release 6, connect servo priming apparatus 16, close other water delivering orifices of permeameter, add water, make gas pass through air release 6 and discharge by servomechanism installation 16 from pressure water injection pipe 5.When air release 6 has water to overflow, illustrate that gas drains in the permeameter, tighten air release 6.Just can add the water pressurization then, judge the numerical value that whether the permeameter internal pressure reaches needs by water pressure gauge 3 with servo priming apparatus 16.

3. testing procedure at first must form steady seepage, opens permeameter bottom water delivering orifice 13, the servo priming apparatus 16 in top supplies water and pressurizes, regulate water supply speed and go out water speed and make it approximately to equate that make the stable seepage flow of formation in the sample, at this moment the reading of pressure gauge 3 does not change substantially in time; Read three pressure gauge reading P1, P2, P3, the discharge Q in the t time, coolant-temperature gage T; Calculate the sample infiltration coefficient according to following formula:

K_{T} = \frac{QL}{AHt}

In the formula: K _TThe infiltration coefficient of sample (cm/s) when-water temperature is T ℃;

Ooze out the water yield (cm in Q-time t second ³);

In the heart distance (cm) in adjacent two pressure taps of L-, this instrument is 20cm;

A-sample floorage (cm ²);

Average water head between adjacent two pressure taps of H-is poor, H=(2P ₁-P ₂-P ₃(cm) calculated in)/3;

The t-time (s).

Infiltration coefficient under the standard temperature (promptly 20 ℃) should be calculated as follows:

K_{20} = K_{T} \frac{η_{T}}{η_{20}}

η in the formula _TThe coefficient of dynamic viscosity of water in the time of-T ℃, its value are tabled look-up and can be got (kPas);

η ₂₀The coefficient of dynamic viscosity of water in the time of-20 ℃, its value are tabled look-up and can be got (kPas).

Claims

1. servocontrol transformation permeameter, it is by upper end cover (4), last water filling forcing pipe (5), air release (6), infiltration tube (7), survey hydraulic devices for 6, porous disc (8), the sky chamber of catchmenting, flange (9), bottom end cover (10), dolly (11), O-ring seal (12), water delivering orifice (13), following water filling forcing pipe (14), servo priming apparatus (16), cock of water drain constitutes, it is characterized in that: upper end cover (4) is salable detachable with infiltration tube (7), have last water filling forcing pipe (5) to connect servo priming apparatus (16) in the middle of the upper end cover (4) and increase setting-out, air release (6) is exitted when being convenient to seal; The infiltration tube equidistant 200mm in (7) both sides connects 6 and surveys hydraulic devices, surveys hydraulic devices and comprises that three-way pipe (2), clear plastic piezometric tube (15) survey low hydraulic pressure, scaleplate (1) reading, water pressure gauge (3) and survey high hydraulic pressure for described 6; Water enters the sky chamber of catchmenting by porous disc (8), and water delivering orifice (13) connects cock of water drain, controls out water speed; By following water filling forcing pipe (14) the sample water filling is pressurizeed; Permeameter is by flange (9) and O-ring seal (12) sealing.