Summary of the invention
The purpose of this invention is to provide a kind of apparatus for unsaturated seepage experiment of rock cranny.
It has the Ma Shi bottle, the Ma Shi bottle is placed on first electronic balance, the Ma Shi bottle joins through the water supply hose and first end cap, in end cap, be provided with capillary barrier, air hole, be provided with the air inlet sulculus in the capillary barrier, the air inlet sulculus communicates with air hole, first end cap, be connected with first tensiometer on the capillary barrier, first end cap is placed on the lifting table, on lifting table, be placed with second end cap, second end cap with the first end cap corresponding section, be connected with second tensiometer on the capillary barrier, delivery hose, the delivery hose other end and organic glass tube join, organic glass tube upper end joins through run-down pipe and organic glass cup, and the organic glass cup is placed on second electronic balance.
Described capillary barrier is selected porous mortar for use.Porous mortar is by water: cement: sand=1.3~1.5: 1: 4~6 cooperate to build and form.The particle diameter of sand is 0.315~0.63mm.
The present invention is simple in structure, and is easy and simple to handle, solved the deficiency of traditional water-gas, water-oily two-phase flow test unit or quasi-stable state displacement test device, can record crack unsaturated water force parameter truly, the test accuracy height.
Embodiment
As Fig. 1, shown in 2, apparatus for unsaturated seepage experiment of rock cranny has Ma Shi bottle 1, the Ma Shi bottle is placed on first electronic balance 2, the Ma Shi bottle joins through the water supply hose 3 and first end cap 4, in end cap, be provided with capillary barrier 6, air hole 15, be provided with air inlet sulculus 16 in the capillary barrier, the air inlet sulculus communicates with air hole, first end cap, be connected with first tensiometer 8 on the capillary barrier, first end cap is placed on the lifting table 14, on lifting table, be placed with second end cap 5 with the first end cap corresponding section, second end cap, be connected with second tensiometer 9 on the capillary barrier, delivery hose 7, the delivery hose other end and organic glass tube 10 join, and organic glass tube upper end joins through run-down pipe 11 and organic glass cup 12, and the organic glass cup is placed on second electronic balance 13.
Implementation process of the present invention is: press end cap size well cutting crack test specimen, place between two end caps crack test specimen and clamping, the dual-side that the crack test specimen is parallel to current direction is coated with epoxy resin in case leak.Allow full water such as crack and capillary barrier earlier; Use test specimen position, lifting table lifting crack again, make that water pressure becomes certain negative value in the crack, by capillary sticking theory as can be known, the crack will begin draining.From lifting zero hour, the water yield variable quantity in the measuring and calculating identical period of plurality of adjacent in water-supply quantity, the water yield of catchmenting and the tensiometer is until steady flow condition (think to flow during water yield variable quantity sum in water-supply quantity in certain period equals to catchment the water yield and tensiometer and reached steady state (SS)).By principle of water balance as can be known, the accumulative total difference of the water yield variable quantity sum in water-supply quantity and the catchment water yield and the tensiometer is the water yield that the crack is discharged under the effect of this grade capillary pressure, according to the saturation moisture content in crack, can try to achieve the pairing crack of this grade capillary pressure saturation degree.Record the interior water yield of given period behind mobile the stablizing,, can try to achieve the unsaturation infiltration coefficient of crack under this grade capillary pressure again according to average aperture, length and the width in Darcy's law and crack by the crack.Lifting crack test specimen step by step repeats above-mentioned steps, can survey the capillary pressure~saturation degree when trying to achieve the draining of a series of cracks and the relation data point of unsaturation infiltration coefficient~capillary pressure.In like manner, from test specimen extreme higher position, crack, utilize lifting table to reduce test specimen position, crack (crack will begin suction) step by step, can survey the capillary pressure~saturation degree when trying to achieve the suction of a series of cracks and the relation data point of unsaturation infiltration coefficient~capillary pressure.
As shown in Figure 1, the capillary pressure h of water in the crack of certain test specimen position, crack correspondence
cFor:
In the formula: h
1Be the discrepancy in elevation of the fissure-plane and the first tensiometer middle water level, the i.e. capillary pressure of crack influent side; h
2Be the discrepancy in elevation of the fissure-plane and the second tensiometer middle water level, the i.e. capillary pressure of crack water outlet side; h
cAverage capillary pressure value for water in the crack.
(corresponding capillary pressure is h by position 1 when the crack test specimen
C1) 2 (corresponding capillary pressure is h to the position in lifting (or reduce)
C2) time, by capillary sticking theory as can be known, the crack is with draining (or suction), and current need just can reach new steady flow condition after after a while in it.Note gw
1, gw
2..., gw
nFor after lifting (or reduce) beginning current in the crack reach new steady flow condition, the water-supply quantity in n adjacent period (by at the beginning of the period and period Mo first electronic balance reading the difference conversion and get); Jw
1, jw
2..., jw
nFor after lifting (or reduce) beginning current in the crack reach new steady flow condition, the water yield of catchmenting in n adjacent period (by at the beginning of the period and period Mo second electronic balance reading the difference conversion and get); Zw
1, zw
2..., zw
nFor after lifting (or reduce) beginning current in the crack reach new steady flow condition, the variable quantity of the water yield in n adjacent period internal tension meter (according at the beginning of the period and period Mo two tensiometer SEA LEVEL VARIATIONS DURING value try to achieve, increase to just).According to principle of water balance, capillary pressure is by h
C1Become h
C2After, promptly corresponding to capillary pressure h
C2Crack water discharge (or water absorbing capacity) Δ θ be:
Δθ=|(jw+zw)-gw| (2)
In the formula: jw=jw
1+ jw
2+ ...+jw
n, zw=zw
1+ zw
2+ ...+zw
n, gw=gw
1+ gw
2+ ... + gw
n
The same, change the relation data point that test specimen position, crack elevation can be tried to achieve a series of capillary pressures and crack water discharge (or water absorbing capacity).
Try to achieve every grade of pairing saturation degree of capillary pressure, also need know the saturation moisture content in crack.For rock cranny, because the water cut of sillar wants big many than the water cut in crack, so the saturation moisture content that the method (as Neutron Moisture instrument method, X ray damped method etc.) of porous medium water cut can not be used to measure the crack is measured in traditional being used to.The way here is: the water discharge under the accumulative total capillary pressures at different levels, multiply by the saturation moisture content of 1.05 (irreducible water saturation in natural crack is generally about 5%, so multiply by 1.05) as the crack again.According to the water discharge (or water absorbing capacity) in crack under saturation moisture content and the capillary pressure at different levels, just can try to achieve the crack saturation degree of certain grade of capillary pressure correspondence.
Under every grade of capillary pressure, wait to flow stable after, record in the given period by the water yield in crack the unsaturation infiltration coefficient in the time of can trying to achieve a series of cracks draining (or suction) and the relation data point of capillary pressure.
The computing formula of saturated (or unsaturation) osmotic coefficient k is as follows:
In the formula: w is the interior water yield (cm by the crack of period t
3); L is crack length (cm); A is crack width (cm); B is the average aperture (cm) in crack, refers to the mechanics aperture here; h
1, h
2Meaning cotype (1).