CN109778599B - In-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load - Google Patents
In-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load Download PDFInfo
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Abstract
The invention relates to the technical field of high-speed railway roadbed, in particular to an in-situ intelligent determination method for permeability coefficient under the upper load of mudstone of a high-speed railway foundation. The advantages are that: overcomes the inconvenience of long-term field residence in the field. The method can truly and effectively reflect the permeability coefficient of mudstone in actual work, and has greater significance to actual engineering.
Description
Technical Field
The invention relates to the technical field of high-speed railway roadbed, in particular to a method for measuring permeability coefficient of a high-speed railway foundation under mudstone overlying load.
Background
The expansive soil is special soil mainly composed of clay minerals with strong hydrophilicity and clay minerals with mixed layers, has the characteristics of water absorption expansion, water loss shrinkage, deformation and damage, repeatability, multiple properties, long-term potential property and the like, and is extremely unfavorable for road base stability and engineering safety. The ballastless track of the high-speed railway has extremely strict requirements on the deformation of the road base, the allowable adjustment quantity of the upper arch is only 4mm, when the high-speed railway passes through the expansive mudstone section, the influence of water on the mudstone can cause the upper arch of the roadbed, so that the smoothness of the track is aggravated, the vibration of rolling stock, the interaction of wheel and rail and the running safety and comfort performance are directly influenced, and the safe operation of the high-speed railway is finally influenced.
The research on the arching of the high-speed railway subgrade caused by the weak expansion mudstone foundation is rarely reported at home and abroad. Along with the rapid development of high-speed railways in China, a large number of railway projects using weak expansion mudstones as foundations are developed. The infiltration of moisture in the mudstone foundation is a main factor influencing the expansion of the mudstone, the larger the infiltrated moisture is, the larger the swellability of the mudstone is, the larger the arch amount of the high-speed railway roadbed is, the change of the overburden load is a key factor influencing the infiltration of the moisture, the larger the overburden load is, the stronger the inhibition effect on the swellability of the mudstone is, the more compact the mudstone is, the more difficult the water is to infiltrate finally, the weaker the inhibition effect on the swellability of the mudstone is due to the smaller overburden load is, and the infiltration of the moisture is easier. The prior method for measuring the permeability coefficient of the mudstone is mostly carried out indoors, but the indoors is influenced by the size effect, boundary conditions, disturbance and the like of the test, and the test result still can not truly and effectively reflect the stress condition of the structure in the actual work; the on-site soil permeability coefficient measurement mode is a double-ring water injection method, but the method only measures the vertical permeability coefficient of the soil under the action of no overburden load, but cannot realize the transverse permeability coefficient and the vertical permeability coefficient of the soil under the action of overburden load.
Therefore, aiming at the blank of the in-situ determination method of the lateral permeability coefficient and the vertical permeability coefficient of the mudstone foundation under different overburden loads, a determination method which is simple and intelligent to operate and low in cost is urgently needed.
Disclosure of Invention
The invention aims to provide an in-situ intelligent determination method for permeability coefficient of a high-speed railway foundation under mudstone overburden load.
In order to achieve the above purpose, the present invention provides the following technical solutions: the device comprises a loading top plate, wherein a stacking object is placed on the upper surface of the loading top plate, a loading upright post is arranged on the lower surface of the loading top plate, the lower end of the loading upright post is placed on a loading bottom plate, an upper through hole and a lower through hole are formed in the center of the loading bottom plate, a seepage channel is arranged in the through hole and extends downwards, the inside of the seepage channel is hollow, and water seepage holes are formed in the side wall and the bottom wall of the seepage channel; the waterproof film and sand are arranged on the bottom surface of the loading bottom plate; the inner wall of the seepage passage is fixedly provided with a humidity sensor, the humidity sensor is connected with a humidity control switch through a first humidity signal wire, the humidity control switch is connected with an electric actuating mechanism through a wire, the electric actuating mechanism is connected with an electric valve, the electric actuating mechanism controls the electric valve to be opened and closed, the electric valve is arranged on a water pipe, one end of the water pipe is connected with a water storage bucket, and the other end of the water pipe extends into the seepage passage; the humidity control switch is connected with the controller through a power line, and the water delivery pipe is provided with a flowmeter and a manual valve; the horizontal humidity sensor and the vertical humidity sensor are distributed at the horizontal position and the vertical position of the seepage channel, the horizontal humidity sensor and the vertical humidity sensor are connected to the humidity inspection instrument through a second humidity signal line, the humidity inspection instrument is connected with the controller through a power line, the horizontal humidity sensor is distributed in multiple layers by taking the seepage channel as a circle center, and the vertical humidity sensor is distributed in multiple layers below the seepage channel in an up-down direction; the controller is provided with 3 pairs of wire ends, the anode and the cathode of the pair of wire ends are connected with the power supply device, the anode and the cathode of the pair of wire ends are connected with the storage battery, and the anode and the cathode of the pair of wire ends are connected with the humidity control switch and the humidity inspection instrument.
The operation and measurement processes are as follows: 1) Selecting a field in a planned measurement area, removing earth surface floating soil, excavating a test foundation pit, and leveling the pit bottom after the foundation pit is excavated;
2) Excavating a temporary surface on one side of the foundation pit, wherein the depth of the temporary surface is larger than that of the foundation pit;
3) Excavating a circular test area at the bottom of the foundation pit, and leveling each test area after finishing;
4) Drilling a vertical water injection hole in the center of a circular area of the foundation pit;
5) Drilling a transverse humidity sensor placing hole along the vertical direction around the water injection hole; excavating a vertical humidity sensor placing hole on the side wall of the empty face below the foundation pit;
6) Respectively placing a transverse humidity sensor and a vertical humidity sensor in a transverse humidity sensor placing hole and a vertical humidity sensor placing hole, paying attention to the fact that a sensor probe is in solid soil contact with a hole wall, connecting a transverse humidity sensor signal line and a vertical humidity sensor signal line with a humidity inspection instrument, starting the humidity inspection instrument, and checking whether the humidity sensor operates normally or not, and if abnormal, immediately replacing;
7) Spreading a layer of sand on the surface of a circular area of the foundation pit, wherein the upper surface of the sand is level, the sand layer is reserved with holes for seepage channels and is prevented from falling into water injection holes, a waterproof film is spread on the surface of the sand to prevent water from evaporating from the surface of a soil body during water injection, and the center of the waterproof film is provided with holes for the seepage channels to pass through;
8) The upper end of the seepage channel is inserted into the through hole of the loading bottom plate, the seepage channel is placed into the water injection hole, and the loading bottom plate is placed on the waterproof membrane;
9) The upper surface of the loading bottom plate is provided with a loading upright post, a loading top plate is placed on the loading upright post, and a stacking object is placed on the upper surface of the loading top plate, so that the stacking object reaches a target overlying load value;
10 The humidity control switch is powered on, the manual valve is opened, the water pipe is connected with water, the electric executing mechanism, the electric valve and the humidity control switch are linked, when the humidity of the humidity sensor is a set low value, the humidity control switch receives a humidity signal to set the low value, the electric executing mechanism and the electric valve are controlled to be opened by the humidity control switch, and water flows into the seepage channel; when the humidity of the humidity sensor is set to be a high value, the humidity control switch receives a humidity signal to set the high value, and the humidity control switch controls the electric actuator and the electric valve to be closed, so that water injection into the seepage channel is stopped, and the requirement that water exists in the seepage channel but does not overflow is met;
11 Observing and recording readings of a transverse humidity sensor and a vertical humidity sensor, wherein after the readings of all the transverse humidity sensor and the vertical humidity sensor are stable, the mud rock in a test area is uniformly and completely permeated;
12 Mudstone seepage rate calculation:
taking three layers as an example, the distances from the first layer, the second layer and the third layer of transverse humidity sensor to the edge of the water seepage channel are respectively h 1 、h 2 、h 3 ，h 1 ＜h 2 ＜h 3 The distances from the first layer, the second layer and the third layer of vertical humidity sensors to the bottom of the water seepage channel are respectively s from top to bottom 1 、s 2 、s 3 ，s 1 ＜s 2 ＜s 3 ；
The time taken by the first layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 11 、t 12 、t 13 、t 14 The time taken by the second layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 21 、t 22 、t 23 、t 24 Transverse of third layerThe time taken by the humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 31 、t 32 、t 33 、t 34 The time taken by the first layer, the second layer and the third layer of vertical humidity sensor from the initial measurement of the volume water content to the final stabilization of the volume water content is respectively t 1 、t 2 、t 3 ；
Mudstone lateral seepage rate: a first layer: v 11 =h 1 /t 11 、v 12 =h 1 /t 12 、v 13 =h 1 /t 13 、v 14 =h 1 /t 14 Average v 1p =（v 11 + v 12 + v 13 +v 14 ）/4
A second layer: v 21 =h 2 /t 21 、v 22 =h 2 /t 22 、v 23 =h 2 /t 23 、v 24 =h 2 /t 24 Average v 2p =（v 21 + v 22 + v 23 +v 24 ）/4
Third layer: v 31 =h 3 /t 31 、v 32 =h 3 /t 32 、v 33 =h 3 /t 33 、v 34 =h 3 /t 34 Average v 3p =（v 31 + v 32 + v 33 +v 34 ）/4
Vertical seepage rate of mudstone: a first layer: v 1 =s 1 /t 1 And (2) a second layer: v 2 =s 2 /t 2 Third layer: v 3 =s 3 /t 3
The unit of distance adopts m, the unit of time adopts s, and then the unit of transverse seepage rate and vertical seepage rate is m/s, and the seepage rate is consistent with the seepage coefficient dimension, and because the measurement is on site, and the measurement is the undisturbed mudstone, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone on site under the action of the overlying load are obtained, and when the weight of the piled material is changed and the positions of the humidity sensors are different, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone under different overlying loads and at different seepage distances are obtained.
Preferably, the water seepage holes on the seepage channels are plum blossom-shaped, and 4 rows of water seepage holes are arranged on the side walls.
Furthermore, the size of the water seepage holes on the side wall of the seepage channel tends to be reduced from top to bottom.
Preferably, the number of the transverse humidity sensors is 24, the 24 transverse humidity sensors are respectively divided into an upper layer and a lower layer, each layer is respectively distributed at 0 degrees, 90 degrees, 180 degrees and 270 degrees in the clockwise direction when seen from top to bottom along the seepage channel.
Preferably, the number of the vertical humidity sensors is 3, and the vertical humidity sensors are arranged in three layers right below the center of the seepage channel.
Preferably, the humidity inspection instrument is provided with a measuring signal wireless transmission device
Furthermore, the power supply device adopts solar energy to supply power, the anode and the cathode of a pair of terminals in the controller are connected with a solar cell panel, and the solar cell panel supplies power to a humidity control switch, a humidity inspection instrument, an electric actuating mechanism and an electric valve in daytime through the controller and also charges a storage battery; and at night, the electric power is supplied to the humidity control switch, the humidity inspection instrument, the electric actuating mechanism and the electric valve through the storage battery.
The loading top plate and the loading bottom plate are round steel plates.
Based on the technical scheme, the invention has at least the following advantages:
1. the permeability coefficient in-situ measurement device under the upper load of the high-speed railway mudstone foundation overcomes the traditional manual water injection mode by a full-automatic intelligent water injection mode of a humidity sensor, a humidity control switch, an electric actuating mechanism, an electric valve and a water storage barrel, and ensures all-weather uninterrupted permeability of the mudstone.
2. According to the in-situ determination device for the permeability coefficient of the high-speed railway mudstone foundation under the overburden load, the transverse permeability coefficient and the vertical permeability coefficient of the mudstone can be calculated according to the change condition, the permeability distance and the permeability time of the volume moisture content by measuring the volume moisture content of the mudstone through the transverse humidity sensor, the vertical humidity sensor and the humidity inspection instrument.
3. The permeability coefficient in-situ measurement device under the upper load of the high-speed rail mudstone foundation can realize all-weather and full-automatic data acquisition through the solar cell panel, the controller, the storage battery and the wireless transmission humidity inspection instrument, and overcomes the problems of outdoor power supply and inconvenience of long-term on-site residence of testers caused by slower permeation and longer permeation time of undisturbed soil.
4. The in-situ determination device for the permeability coefficient of the high-speed rail mudstone foundation under the overburden load is convenient to construct, high in automation intelligent degree and low in cost, and compared with other soil permeability coefficient determination methods, the method can truly and effectively reflect the permeability coefficient of the mudstone in actual work and has greater significance for actual engineering.
Drawings
FIG. 1 is a top view field construction layout;
FIG. 2 is a side view of a field construction layout;
FIG. 3 is an elevational view of a test area;
FIG. 4 is a side expanded view of a percolation channel;
FIG. 5 is a schematic diagram of the structural composition of the present invention;
FIG. 6 is a graph of time course for a lateral humidity sensor (a) and a vertical humidity sensor (b) at an overlay load of 15 kPa;
FIG. 7 is a graph of time course for a lateral humidity sensor (a) and a vertical humidity sensor (b) at an overlay load of 30 kPa;
FIG. 8 is a graph of the time course of the lateral humidity sensor (a) and the vertical humidity sensor (b) at an overlay load of 45 kPa;
FIG. 9 transverse permeability coefficient (a) and vertical permeability coefficient (b) at different overburden loads;
fig. 10 is a schematic view of a quincuncial water permeable hole;
in the figure: 1-loading top plate, 2-stacking object, 3-loading upright post, 4-loading bottom plate, 5-seepage channel, 6-humidity sensor, 7-first humidity signal wire, 8-humidity control switch, 9-electric wire, 10-electric actuator, 11-electric valve, 12-water delivery pipe, 13-water storage bucket, 14-power wire, 15-controller, 16-transverse humidity sensor, 17-vertical humidity sensor, 18-second humidity signal wire, 19-humidity inspection instrument, 20-solar panel, 21-storage battery, 22-flowmeter, 23-manual valve, 24-ground, 25-waterproof film, 26-sand, 35-free surface, 36-transverse humidity sensor arrangement hole, 37-test area, 38-water injection hole, 39-vertical humidity sensor arrangement hole, 40-seepage hole, 41-test area, 42-horizontal drilling.
Detailed Description
The technical scheme of the invention is clearly and completely described below with reference to the accompanying drawings.
The device is shown by referring to figures 4-5, and comprises a loading top plate 1, a stacking object 2 is placed on the upper surface of the loading top plate 1, a loading upright post 3 is arranged on the lower surface of the loading top plate 1, the lower end of the loading upright post 3 is placed on a loading bottom plate 4, an upper through hole and a lower through hole are formed in the center of the loading bottom plate 4, a seepage channel 5 is arranged in the through hole, the seepage channel 5 extends downwards, the inside is hollow, and water seepage holes 40 are formed in the side wall and the bottom wall; the waterproof membrane 25 and sand 26 are arranged on the bottom surface of the loading bottom plate 4; the inner wall of the seepage channel 5 is fixedly provided with a humidity sensor 6, the humidity sensor 6 is connected with a humidity control switch 8 through a first humidity signal wire 7, the humidity control switch 8 is connected with an electric actuator 10 through a wire 9, the electric actuator 10 is connected with an electric valve 11, the electric actuator 10 controls the electric valve 11 to be opened and closed, the electric valve 11 is arranged on a water pipe 12, one end of the water pipe 12 is connected with a water storage bucket 13, and the other end extends into the seepage channel 5; the humidity control switch 8 is connected with the controller 15 through a power line 14, and the water pipe 12 is provided with a flowmeter 22 and a manual valve 23; the transverse humidity sensor 16 and the vertical humidity sensor 17 are arranged at the transverse position and the vertical position of the seepage channel 5, the transverse humidity sensor 16 and the vertical humidity sensor 17 are connected to the humidity inspection instrument 19 through the second humidity signal line 18, the humidity inspection instrument 19 is connected with the controller 15 through the power line 14, the transverse humidity sensor 16 is arranged in multiple layers by taking the seepage channel as a circle center, and the vertical humidity sensor 17 is arranged in multiple layers below the seepage channel in an up-down mode; the controller 15 has 3 pairs of terminals, wherein a left pair of positive and negative terminals is connected to the solar cell panel 20, a middle pair of positive and negative terminals is connected to the storage battery 21, and a right pair of positive and negative terminals is connected to the humidity control switch 8 and the humidity inspection instrument 19. The solar panel 20 supplies power to the humidity control switch 8, the humidity inspection instrument 19, the electric actuator 10 and the electric valve 11 through the controller 15 in daytime, and also charges the storage battery 21; at night, the electric power is supplied to the humidity control switch 8, the humidity inspection instrument 19, the electric actuator 10 and the electric valve 11 through the storage battery 21. The solar energy is adopted to supply power, so that the problem of inconvenient power consumption in the field can be solved.
The operation and measurement processes are as follows: 1-3 and 5, 1) selecting a field in a planned measurement area, removing floating soil with the earth surface thickness of about 0.4m, excavating a test foundation pit, wherein the bottom dimension of the foundation pit is 2m multiplied by 1.75m, the depth is 0.4m, the side slope ratio is 2:1, and leveling the bottom of the pit after the foundation pit is excavated.
2) And excavating a free surface on one side of the foundation pit, wherein the depth of the free surface is larger than that of the foundation pit, and the length, width and depth of the free surface are 2m multiplied by 0.5m multiplied by 2m.
3) And excavating a circular test area at the bottom of the foundation pit, wherein the diameter of the circular test area is 0.75m, and the depth of the circular test area is 0.1m, and leveling each test area after finishing.
4) And drilling a vertical water injection hole with the diameter of 0.08m and the depth of 0.5m in the center of the circular area of the foundation pit by using a drilling machine.
5) Drilling a transverse humidity sensor placing hole along the vertical direction around the water injection hole; and excavating a vertical humidity sensor placing hole on the side wall of the empty face below the foundation pit.
6) The transverse humidity sensor 16 and the vertical humidity sensor 17 are respectively placed in the transverse humidity sensor placing hole and the vertical humidity sensor placing hole, the sensor probe is in contact with the solid soil of the hole wall, and is preferably inserted into the solid soil of the hole wall, the signal wire of the transverse humidity sensor and the vertical humidity inspection instrument 19 are connected, the humidity inspection instrument is started, whether the operation of the humidity sensor is normal or not is checked, and if abnormal, the humidity sensor is replaced immediately.
7) The circular area surface of foundation ditch spreads one deck sand, and sand upper surface is whole level, and the sand bed is to be reserved the hole for seepage flow passageway and prevent sand fall into the water injection hole, spreads the water proof membrane (from the polymer material membrane can, like polyethylene film) on sand surface, prevents that moisture from evaporating from soil body surface when the water injection, and the water proof membrane center is seepage flow passageway and has the hole of digging.
8) The upper end of the seepage passage 5 is inserted into the through hole of the loading bottom plate 4, the seepage passage 5 is placed into the water injection hole, and the loading bottom plate 4 is placed on the waterproof membrane.
9) The loading upright post 3 is arranged on the upper surface of the loading bottom plate 4, the loading top plate 1 is arranged on the loading upright post 3, and the stacking object 2 is arranged on the upper surface of the loading top plate 1, so that the stacking object reaches a target overlying load value.
10 The humidity control switch 8 is powered on, the manual valve is opened, the water pipe 12 is connected with water, the electric actuating mechanism, the electric valve and the humidity control switch are linked, when the humidity of the humidity sensor is a set low value (the probe is not in direct contact with water), the humidity control switch receives a humidity signal to set the low value, and the electric actuating mechanism and the electric valve are controlled to be opened by the humidity control switch, so that water flows into the seepage channel; when the humidity of the humidity sensor is set to be a high value, the humidity control switch receives a humidity signal to set the high value (the humidity is maximum, and the probe is in direct contact with water), the humidity control switch controls the electric actuator and the electric valve to be closed, water injection to the seepage channel is stopped, and the requirement that the seepage channel has water but does not overflow is met.
11 The readings of the transverse humidity sensor and the vertical humidity sensor are observed and recorded, and after the readings of all the transverse humidity sensor and the vertical humidity sensor are stable, the mud rock in the test area is uniformly and completely permeated.
12 Mudstone seepage rate calculation:
the distance from the first layer, the second layer and the third layer of transverse humidity sensor to the edge of the water seepage channel is h respectively 1 、h 2 、h 3 ，h 1 ＜h 2 ＜h 3 The distances from the first layer, the second layer and the third layer of vertical humidity sensors to the bottom of the water seepage channel are respectively s from top to bottom 1 、s 2 、s 3 ，s 1 ＜s 2 ＜s 3 ；
The time taken by the first layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 11 、t 12 、t 13 、t 14 The time taken by the second layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 21 、t 22 、t 23 、t 24 The time taken by the third layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 31 、t 32 、t 33 、t 34 The time taken by the first layer, the second layer and the third layer of vertical humidity sensor from the initial measurement of the volume water content to the final stabilization of the volume water content is respectively t 1 、t 2 、t 3 ；
Mudstone lateral seepage rate: a first layer: v 11 =h 1 /t 11 、v 12 =h 1 /t 12 、v 13 =h 1 /t 13 、v 14 =h 1 /t 14 Average v 1p =（v 11 + v 12 + v 13 +v 14 ）/4
A second layer: v 21 =h 2 /t 21 、v 22 =h 2 /t 22 、v 23 =h 2 /t 23 、v 24 =h 2 /t 24 Average v 2p =（v 21 + v 22 + v 23 +v 24 ）/4
Third layer: v 31 =h 3 /t 31 、v 32 =h 3 /t 32 、v 33 =h 3 /t 33 、v 34 =h 3 /t 34 Average v 3p =（v 31 + v 32 + v 33 +v 34 ）/4
Vertical seepage rate of mudstone: a first layer: v 1 =s 1 /t 1 And (2) a second layer: v 2 =s 2 /t 2 Third layer: v 3 =s 3 /t 3 。
The unit of distance adopts m, the unit of time adopts s, and then the unit of transverse seepage rate and vertical seepage rate is m/s, and the seepage rate is consistent with the seepage coefficient dimension, and because the measurement is on site, and the measurement is the undisturbed mudstone, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone on site under the action of the overlying load are obtained, and when the weight of the piled material is changed and the positions of the humidity sensors are different, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone under different overlying loads and at different seepage distances are obtained.
The further preferable scheme is as follows: the water seepage holes on the seepage channel 5 are in a plum blossom shape, 4 rows of water seepage holes are arranged on the side wall, and the plum blossom shape can not only enable water seepage to be smooth, but also prevent soil particles caused by large aperture from entering the seepage channel.
The more preferable scheme is as follows: the size of the water seepage holes on the side wall of the seepage channel 5 tends to be reduced from top to bottom. The aperture of the bottom water seepage hole is 0.5cm, the aperture of the lowest part of the side wall water seepage hole is 0.5cm, and the aperture of the water seepage hole is increased by 0.01cm on the basis of 0.5cm along with the increase of the height of the water seepage channel. Because different depth pressures of water in the seepage channel can lead to higher seepage speed of the lower hole of the seepage channel and lower seepage speed of the upper hole, the water content of the soil body of the lower part is higher, the water content of the soil body of the upper part is lower, the deviation of measured data of humidity sensors of the upper layer and the lower layer is large, and the usability of the data is affected. The problem can be solved by adopting a structure with gradually changing pore size.
The number of the transverse humidity sensors 16 is 24, and the 24 transverse humidity sensors 16 are respectively divided into an upper layer and a lower layer, and each layer is arranged along the seepage channel 5 at 0 degrees, 90 degrees, 180 degrees and 270 degrees clockwise when seen from top to bottom. The number of the vertical humidity sensors 17 is 3, and the vertical humidity sensors are arranged in three layers right below the center of the seepage channel 5. The arrangement mode of up-down and inner-outer layers is adopted, the comprehensiveness of measured data can be guaranteed, and the data availability is high.
In order to reduce the personnel on duty time, the humidity inspection instrument 19 is provided with a measuring signal wireless transmission function. The signals are transmitted through the wireless signal transmitting and receiving device, so that remote observation and recording can be realized. The humidity inspection instrument 19 records the values of the horizontal humidity sensor 16 and the vertical humidity sensor 17 every 20 minutes, and transmits the values back to the indoor receiving device through the wireless transmission function carried by itself.
The loading top plate 1 and the loading bottom plate 4 are all round steel plates, so that stress uniformity can be improved.
Example analysis
As shown in figures 6, 7 and 8, the device is adopted to carry out the determination of the lateral permeability coefficient and the vertical permeability coefficient of mudstone under three kinds of overburden loads of 15kPa, 30kPa and 45kPa on an upwarp section of a typical roadbed of Lanxingao. Fig. 9 shows the transverse permeability coefficient and the vertical permeability coefficient of the mudstone foundation of the high-speed railway under different overburden loads, which are measured and calculated by the method, and as can be known from fig. 9, the method can meet the requirements of field tests, and can make up for the blank of the in-situ measurement method of the transverse permeability coefficient and the vertical permeability coefficient of the mudstone foundation under different overburden loads.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.
Claims (8)
1. An in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under an overlying load is characterized by comprising the following steps: the device comprises a loading top plate (1), wherein a stacking object (2) is placed on the upper surface of the loading top plate (1), a loading upright post (3) is arranged on the lower surface of the loading top plate (1), the lower end of the loading upright post (3) is placed on a loading bottom plate (4), an upper through hole and a lower through hole are formed in the center of the loading bottom plate (4), a seepage channel (5) is arranged in the through hole, the seepage channel (5) extends downwards, the inside of the seepage channel is hollow, and seepage holes (40) are formed in the side wall and the bottom wall of the seepage channel; the bottom surface of the loading bottom plate (4) is provided with a waterproof membrane (25) and sand (26); the device is characterized in that a humidity sensor (6) is fixed on the inner wall of the seepage channel (5), the humidity sensor (6) is connected with a humidity control switch (8) through a first humidity signal wire (7), the humidity control switch (8) is connected with an electric actuating mechanism (10) through a wire (9), the electric actuating mechanism (10) is connected with an electric valve (11), the electric actuating mechanism (10) controls the electric valve (11) to be opened and closed, the electric valve (11) is arranged on a water pipe (12), one end of the water pipe (12) is connected with a water storage bucket (13), and the other end of the water pipe stretches into the seepage channel (5); the humidity control switch (8) is connected with the controller (15) through a power line (14), and the water delivery pipe (12) is provided with a flowmeter (22) and a manual valve (23); the seepage channel (5) is provided with a transverse humidity sensor (16) and a vertical humidity sensor (17) at the transverse position and the vertical position, the transverse humidity sensor (16) and the vertical humidity sensor (17) are connected to a humidity inspection instrument (19) through a second humidity signal line (18), the humidity inspection instrument (19) is connected with a controller (15) through a power line (14), the transverse humidity sensor (16) is distributed in multiple layers by taking the seepage channel as a center of a circle, and the vertical humidity sensor (17) is distributed in multiple layers below the seepage channel in an up-down mode; the controller (15) is provided with 3 pairs of wire heads, the anode and the cathode of the pair of wire heads are connected with the power supply device, the anode and the cathode of the pair of wire heads are connected with the storage battery (21), and the anode and the cathode of the pair of wire heads are connected with the humidity control switch (8) and the humidity inspection instrument (19);
the operation and measurement processes are as follows: 1) Selecting a field in a planned measurement area, removing earth surface floating soil, excavating a test foundation pit, and leveling the pit bottom after the foundation pit is excavated;
2) Excavating a temporary surface on one side of the foundation pit, wherein the depth of the temporary surface is larger than that of the foundation pit;
3) Excavating a circular test area at the bottom of the foundation pit, and leveling each test area after finishing;
4) Drilling a vertical water injection hole in the center of a circular area of the foundation pit;
5) Drilling a transverse humidity sensor placing hole along the vertical direction around the water injection hole; excavating a vertical humidity sensor placing hole on the side wall of the empty face below the foundation pit;
6) A transverse humidity sensor (16) and a vertical humidity sensor (17) are respectively placed in a transverse humidity sensor placing hole and a vertical humidity sensor placing hole, a sensor probe is in contact with solid soil on the hole wall, a transverse humidity sensor signal line and a vertical humidity sensor signal line are connected with a humidity inspection instrument (19), the humidity inspection instrument is started, whether the humidity sensor operates normally or not is checked, and if abnormal, the humidity sensor is replaced immediately;
7) Spreading a layer of sand on the surface of a circular area of the foundation pit, wherein the upper surface of the sand is level, the sand layer is reserved with holes for seepage channels and is prevented from falling into water injection holes, a waterproof film is spread on the surface of the sand to prevent water from evaporating from the surface of a soil body during water injection, and the center of the waterproof film is provided with holes for the seepage channels to pass through;
8) The upper end of the seepage channel (5) is inserted into a through hole of the loading bottom plate (4), the seepage channel (5) is placed in the water injection hole, and the loading bottom plate (4) is placed on the waterproof membrane;
9) The upper surface of the loading bottom plate (4) is provided with a loading upright post (3), a loading top plate (1) is placed on the loading upright post (3), and a stacking object (2) is placed on the upper surface of the loading top plate (1) to enable the stacking object to reach a target overlying load value;
10 The humidity control switch (8) is powered on, the manual valve is opened, the water pipe (12) is connected with water, the electric actuating mechanism, the electric valve and the humidity control switch are linked, when the humidity of the humidity sensor is a set low value, the humidity control switch receives a humidity signal to set the low value, the electric actuating mechanism and the electric valve are controlled to be opened by the humidity control switch, and water flows into the seepage channel; when the humidity of the humidity sensor is set to be a high value, the humidity control switch receives a humidity signal to set the high value, and the humidity control switch controls the electric actuator and the electric valve to be closed, so that water injection into the seepage channel is stopped, and the requirement that water exists in the seepage channel but does not overflow is met;
11 Observing and recording readings of a transverse humidity sensor and a vertical humidity sensor, wherein after the readings of all the transverse humidity sensor and the vertical humidity sensor are stable, the mud rock in a test area is uniformly and completely permeated;
12 Mudstone seepage rate calculation:
taking three layers as an example, the distances from the first layer, the second layer and the third layer of transverse humidity sensor to the edge of the water seepage channel are respectively h 1 、h 2 、h 3 ，h 1 ＜h 2 ＜h 3 From top to bottom, a first layer,The distance between the second layer and the third layer of vertical humidity sensor and the bottom of the water seepage channel is s respectively 1 、s 2 、s 3 ，s 1 ＜s 2 ＜s 3 ；
The time taken by the first layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 11 、t 12 、t 13 、t 14 The time taken by the second layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 21 、t 22 、t 23 、t 24 The time taken by the third layer transverse humidity sensor from the initial measurement of the volume moisture content to the final stabilization of the volume moisture content is t respectively 31 、t 32 、t 33 、t 34 The time taken by the first layer, the second layer and the third layer of vertical humidity sensor from the initial measurement of the volume water content to the final stabilization of the volume water content is respectively t 1 、t 2 、t 3 ；
Mudstone lateral seepage rate: a first layer: v 11 =h 1 /t 11 、v 12 =h 1 /t 12 、v 13 =h 1 /t 13 、v 14 =h 1 /t 14 Average v 1p =（v 11 + v 12 + v 13 +v 14 ）/4
A second layer: v 21 =h 2 /t 21 、v 22 =h 2 /t 22 、v 23 =h 2 /t 23 、v 24 =h 2 /t 24 Average v 2p =（v 21 + v 22 + v 23 +v 24 ）/4
Third layer: v 31 =h 3 /t 31 、v 32 =h 3 /t 32 、v 33 =h 3 /t 33 、v 34 =h 3 /t 34 Average v 3p =（v 31 + v 32 + v 33 +v 34 ）/4
Vertical seepage rate of mudstone: a first layer: v 1 =s 1 /t 1 And (2) a second layer: v 2 =s 2 /t 2 Third layer: v 3 =s 3 /t 3
The unit of distance adopts m, the unit of time adopts s, and then the unit of transverse seepage rate and vertical seepage rate is m/s, and the seepage rate is consistent with the seepage coefficient dimension, and because the measurement is on site, and the measurement is the undisturbed mudstone, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone on site under the action of the overlying load are obtained, and when the weight of the piled material is changed and the positions of the humidity sensors are different, the transverse seepage coefficient and the vertical seepage coefficient of the undisturbed mudstone under different overlying loads and at different seepage distances are obtained.
2. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the water seepage holes on the seepage channel (5) are plum blossom-shaped, and 4 rows of water seepage holes are arranged on the side wall.
3. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the size of the water seepage holes on the side wall of the seepage channel (5) tends to be reduced from top to bottom.
4. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the number of the transverse humidity sensors (16) is 24, the 24 transverse humidity sensors (16) are divided into an upper layer and a lower layer, each layer is respectively 12, and each layer is arranged along the seepage channel (5) at 0 degree, 90 degrees, 180 degrees and 270 degrees clockwise when seen from top to bottom.
5. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 3, wherein the method comprises the following steps: the number of the vertical humidity sensors (17) is 3, and the vertical humidity sensors are arranged in three layers under the center of the seepage channel (5).
6. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the humidity inspection instrument (19) is provided with a measuring signal wireless transmission device.
7. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the power supply device adopts solar energy to supply power, the anode and the cathode of a pair of terminals in the controller (15) are connected with the solar panel (20), the solar panel (20) supplies power to the humidity control switch (8), the humidity inspection instrument (19), the electric actuator (10) and the electric valve (11) in daytime through the controller (15), and the storage battery (21) is also charged; at night, the storage battery (21) supplies power to the humidity control switch (8), the humidity inspection instrument (19), the electric actuating mechanism (10) and the electric valve (11).
8. The in-situ intelligent determination method for permeability coefficient of high-speed railway foundation mudstone under overburden load according to claim 1, which is characterized by comprising the following steps: the loading top plate (1) and the loading bottom plate (4) are all round steel plates.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011022932A1 (en) * | 2009-08-26 | 2011-03-03 | 中冶集团武汉勘查研究院有限公司 | Testing method and device for foundation bed coefficient test |
| JP2016050389A (en) * | 2014-08-29 | 2016-04-11 | 株式会社奥村組 | Analysis method using vg model for penetration characteristic of unsaturated soil |
| CN106436673A (en) * | 2016-07-22 | 2017-02-22 | 中铁二院工程集团有限责任公司 | Field water immersion testing method of expansive soil foundation under roadbed project |
| CN106596378A (en) * | 2016-12-25 | 2017-04-26 | 湖南城市学院 | Device for batch experiment of soil body rainwater infiltration characteristics and use method thereof |
| CN108801873A (en) * | 2018-04-24 | 2018-11-13 | 兰州交通大学 | Swelled ground permeameter and its application method under a kind of high ferro difference overlying burden and variable hydraulic pressure |
| CN109001098A (en) * | 2018-08-07 | 2018-12-14 | 西南大学 | A kind of instantaneous Penetration Signature tester of soil and soil infiltration characteristics calculation method |
| CN109056738A (en) * | 2018-08-20 | 2018-12-21 | 中铁六局集团天津铁路建设有限公司 | Excavation method below high-speed railway |
-
2019
- 2019-01-29 CN CN201910085680.4A patent/CN109778599B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011022932A1 (en) * | 2009-08-26 | 2011-03-03 | 中冶集团武汉勘查研究院有限公司 | Testing method and device for foundation bed coefficient test |
| JP2016050389A (en) * | 2014-08-29 | 2016-04-11 | 株式会社奥村組 | Analysis method using vg model for penetration characteristic of unsaturated soil |
| CN106436673A (en) * | 2016-07-22 | 2017-02-22 | 中铁二院工程集团有限责任公司 | Field water immersion testing method of expansive soil foundation under roadbed project |
| CN106596378A (en) * | 2016-12-25 | 2017-04-26 | 湖南城市学院 | Device for batch experiment of soil body rainwater infiltration characteristics and use method thereof |
| CN108801873A (en) * | 2018-04-24 | 2018-11-13 | 兰州交通大学 | Swelled ground permeameter and its application method under a kind of high ferro difference overlying burden and variable hydraulic pressure |
| CN109001098A (en) * | 2018-08-07 | 2018-12-14 | 西南大学 | A kind of instantaneous Penetration Signature tester of soil and soil infiltration characteristics calculation method |
| CN109056738A (en) * | 2018-08-20 | 2018-12-21 | 中铁六局集团天津铁路建设有限公司 | Excavation method below high-speed railway |
Non-Patent Citations (1)
| Title |
|---|
| 低黏土矿物含量泥岩浸水膨胀变形的试验研究;马丽娜;严松宏;张戎令;邓洁;李欣;;工业建筑;第45卷(第11期);第116-120页 * |
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