CN210665725U - Saline soil salt expansion characteristic test device under rigidity constraint condition - Google Patents
Saline soil salt expansion characteristic test device under rigidity constraint condition Download PDFInfo
- Publication number
- CN210665725U CN210665725U CN201920833397.0U CN201920833397U CN210665725U CN 210665725 U CN210665725 U CN 210665725U CN 201920833397 U CN201920833397 U CN 201920833397U CN 210665725 U CN210665725 U CN 210665725U
- Authority
- CN
- China
- Prior art keywords
- sample
- rigidity
- barrel
- upper top
- control box
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The utility model relates to a saline soil salt expansion characteristic test device under rigidity constraint condition, which comprises a temperature control box (1), a support frame (2), a sample barrel (3), a rigidity constraint mechanism and a test data detection assembly, wherein the support frame (2), the sample barrel (3) and the rigidity constraint mechanism are all arranged in the temperature control box (1); through the selection of different rigidity restraint mechanisms, different rigidity restraint change environments can be provided, corresponding rigidity restraint conditions are formed by matching the mobility of the ejector rod, and the temperature control box adjusts the temperature of the soil sample to realize freeze-thaw cycle tests under different rigidity restraint conditions. The utility model discloses further add parts such as water filling port (27), weighing device (11), water feeding component (17) and air drying subassembly, can realize the dry wet cycle test under the different rigidity constraint conditions, dry wet-freeze thawing coupling test. The utility model discloses the operation is simple and easy, convenient assembling, but simultaneous measurement sample salt inflation volume of expanding in-process salt and salt power of expanding, the moisture content and the temperature variation of monitoring sample, and the automatic collection degree of data is high.
Description
Technical Field
The utility model relates to a salt stain soil salt expansion characteristic test technical field especially relates to a salt stain soil salt expansion characteristic test device under rigidity constraint condition.
Background
The salinized soil is a general term of various salinized and alkalized soils. The saline soil is mainly divided into inland saline soil, coastal saline soil and plateau saline soil according to distribution. The salinized soil in China has the area of more than 20 ten thousand square kilometers and is the fourth place in the world. Na (Na)2SO4The saline soil is widely distributed in inland and plateau areas of China, and the salt swelling is one of main disease types. Taking the Qinghai-Tibet plateau as an example, the soil in the area is seriously salinized, and the area has special geographic environment, high altitude, large temperature difference, strong solar radiation and violent freeze-thaw cycle. Meanwhile, the dry-wet cycle is frequent in accordance with complicated periodic weather conditions such as rainfall and solar radiation. Na (Na)2SO4Formation of Na in the crystals2SO4·10H2The volume of O expands 3.18 times. Under the action of continuous dry and wet cycles, salt on the surface layer of the soil body is gradually accumulated, salt crystals are continuously dehydrated and combined with water, and the surface layer of the soil body can generate obvious salt expansion damage (Xiaoze bank, Laiyuan, freeze thawing and saline soil water and salt migration rule research under dry and wet cycles [ J]The report on rock mechanics and engineering, 2018,37 (increment 1): 3739-. Under the dual action of freeze-thaw cycle and dry-wet cycle, the saline soil with high salt content has frequent salt expansion diseases, and seriously threatens the stability of buildings (structures) such as airports, roads, pipelines, house buildings and the like. Therefore, the research on the salinization expansion of the saline soil under the comprehensive influence of the freeze-thaw cycle, the dry-wet cycle and the dry-wet cycle has profound practical significance.
At present, the research on the salinization and swelling property of saline soil in academic communities is mostly based on indoor model tests, and salt-frost heaving quantity parameters under single cooling or freeze-thaw cycle are tested and analyzed mainly under the condition of constant load. For example, the invention patent of application No. 201610824301.5 discloses "a high-precision salt expansion test equipment", which mainly comprises a sample barrel, a temperature regulation and control system and a sample humidity control system (comprising a water adding container and an air compressor), wherein the sample barrel comprises an outer barrel and an inner barrel arranged in the outer barrel, an air drying unit is arranged on the inner wall of the inner barrel, and the water adding container is connected to the outer wall of the inner barrel through a pipeline and is communicated with the inner cavity of the inner barrel. Although the device realizes the dry-wet cycle of the sample to a certain extent, the following defects and problems still exist:
1. the salt expansion test can be only carried out under the constraint condition of constant load, the salt expansion test under the complete constraint condition (infinite rigidity, namely constant volume) cannot be carried out, and the salt expansion test under the constraint condition of constant rigidity or variable rigidity cannot be carried out at the same time. However, in practical engineering, the soil bodies at different positions have various constraint forms, so that the salt swelling property of the soil bodies is different. For example, in a building construction project, when salt expansion occurs to soil bodies at the lower part of a foundation, the load of the soil bodies can be regarded as constant and is in a constant load constraint condition; when the salt swelling deformation of the deeper salinized soil body occurs, the upper soil body of the deeper salinized soil body may be compressed and deformed, the constraint force is changed, and the constraint of the deeper salinized soil body can be simplified into the constraint condition of equal rigidity or variable rigidity; the soil body close to the hard rock stratum or under the completely rigid structure is completely limited, the salt expansion force is maximum at the moment, and the salt expansion force can be simplified into a completely constrained condition with infinite rigidity. And the actual salt swelling characteristics of the saline soil can not be truly reflected by the test results under single test conditions when the saline soil in the field is in complex periodic meteorological conditions such as dry-wet cycle, freeze-thaw cycle and the like, and the guiding significance for actual concrete engineering is very limited.
2. The measurement parameter is single, the salt expansion amount in the test process can only be measured, and the salt expansion force in the test is always equal to the overlying load, so that the salt expansion force evolution mechanism in the soil body salt expansion process cannot be monitored, the salt expansion force cannot be subjected to related research and analysis, and the automatic data acquisition degree is low.
3. When the water content is gradually increased, water is added from the side wall of the sample barrel, the water is transversely transferred, and when the water content is gradually decreased, air is blown from the side wall of the sample barrel, which is inconsistent with the conditions of surface water receiving and surface evaporation under the actual natural working condition, and the air is blown in the sample barrel, so that the structural damage of the sample is caused to a certain extent. Unilateral blowing can lead to sample moisture content maldistribution, and in the drying process, because sample moisture content is lower in air intake department, the salt of water is constantly to the air intake migration, greatly causes the bloated inhomogeneity of sample salt, and this kind of inhomogeneity can be along with experimental propulsion and constantly increase.
4. Because the soil for testing is sulfate saline soil, chloride saline soil and the like, the humidity sensor for monitoring the moisture content is generally a TDR sensor based on the time domain reflection principle, and the measurement result is greatly influenced by soluble salt ions (particularly SO)4 2-) The error can reach more than +/-5%, and for a dry-wet cycle test, the moisture content measurement error is within +/-1%, so that the test result is extremely unreliable, the TDR sensor is generally large, and the soil sample can be greatly disturbed in the installation process. Meanwhile, the moisture content of the sample is not uniformly distributed in the drying process, and the moisture sensor can only monitor the moisture content of a certain area of the soil sample and cannot truly reflect the whole actual moisture content of the soil sample.
5. The sample bucket is bucket in the bucket and the complicated structure of merogenesis, and the assembly is loaded down with trivial details to can't realize the visualization of sample bucket.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that a salt stain soil salt expansion characteristic test device under rigidity constraint condition is provided.
In order to solve the above problem, a salt stain soil salt expansion characteristic test device under rigidity constraint condition, include: the temperature control box comprises a support frame, a sample barrel, a rigidity constraint mechanism and a test data detection assembly which are all arranged in the temperature control box; the temperature control box is used for regulating and controlling the internal temperature; the supporting frame is provided with an upper top plate and a lower bottom plate, and the height of the upper top plate and the height of the lower bottom plate are fixed in the test process; the sample barrel is arranged on the lower bottom plate, a soil sample is placed in the sample barrel during testing, a top disc with the diameter matched with the inner diameter of the sample barrel is placed on the top surface of the soil sample, a top rod is arranged on the top surface of the top disc, and the top rod extends upwards through an upper top cover of the sample barrel and can move up and down relative to the upper top cover; the rigidity constraint mechanism comprises an equal rigidity constraint mechanism or a variable rigidity constraint mechanism, the equal rigidity constraint mechanism or the variable rigidity constraint mechanism is selected to be used or not used according to the actual rigidity constraint requirement, and correspondingly formed rigidity constraint conditions comprise an equal rigidity constraint condition, a variable rigidity constraint condition or a constant volume constraint condition; the rigidity restraining mechanism is arranged between the top of the ejector rod and the upper top plate when in use, and the top of the ejector rod is directly connected with the upper top plate when not in use; the test data detection assembly is used for detecting test data in the test process and transmitting the test data to the monitoring terminal.
Preferably, the test data detection assembly comprises a displacement detection probe and/or a pressure detector, the displacement detection probe is used for detecting the vertical displacement of the ejector rod, and the pressure detector is arranged between the top of the ejector rod and the bottom of the rigid ring.
Preferably, one end of the displacement detection probe is arranged on the ejector rod through a fixing block, and the other end of the displacement detection probe extends upwards to penetrate through the upper top cover of the sample barrel and is arranged on the supporting plate.
Preferably, the equal stiffness constraint mechanism is a rigid ring or a cylindrical spring, and the variable stiffness constraint mechanism is a tower spring.
Preferably, the upper end and the lower end of the equal-rigidity constraint mechanism are provided with protruding columns or sunken columns, and the bottom of the upper top plate of the support frame and the top of the ejector rod are provided with sunken columns or protruding columns which are matched with each other to realize insertion connection.
Preferably, the top of the ejector rod is provided with a first concave column, and the lower end of the equal-rigidity constraint mechanism is provided with a first convex column; the bottom of the cavity of the first concave column is provided with a pressure detector, and the first convex column is inserted downwards from the top of the first concave column and directly or indirectly propped against the upper surface of the pressure detector.
Preferably, the device also comprises a temperature detection probe, wherein a probe of the temperature detection probe is inserted into the soil sample through the upper top cover and the top disc and is used for detecting the temperature value of the soil sample in the test process; and/or the device also comprises a plurality of radiation lamps which are uniformly distributed on the inner wall of the temperature control box and are positioned near the sample barrel.
Preferably, the barrel body of the sample barrel is a transparent barrel body, and the device further comprises a first camera for shooting the soil sample in the sample barrel; and/or the device also comprises a parallel soil sample arranged inside the temperature control box and a second camera for shooting the parallel soil sample.
Preferably, the top disc is provided with a water permeable hole, the upper top cover of the sample barrel is provided with a plurality of water injection ports, and the distance between the upper top cover and the upper edge of the barrel body can be finely adjusted; the device also comprises a weigher, a water adding assembly and an air drying assembly, wherein the weigher is arranged below the support frame, the water adding assembly is arranged outside the temperature control box and provides water for the water filling port through a water pipe penetrating through the wall of the temperature control box, and the air drying assembly comprises an air inlet, an air outlet, an air pipeline, an air circulator and an air dehumidifier, wherein the air inlet and the air outlet are communicated with the inside of the temperature control box, and the air circulator and the air dehumidifier are arranged on the air pipeline.
Preferably, the sample barrel comprises a barrel body, and an upper top cover and a lower bottom cover which are arranged at the upper end and the lower end of the barrel body, the upper top cover and the lower bottom cover are connected through a plurality of connecting rods, the part of each connecting rod penetrating out of the upper top cover is provided with an external thread, and a nut matched with the external thread is arranged outside the external thread; an adjusting spring supporting block is arranged at the position, close to the bottom surface of the upper top cover, of the connecting rod, and an adjusting spring is sleeved between the spring supporting block and the upper top cover; the gap between the upper top cover and the upper edge of the barrel body is realized by screwing the nut to enable the adjusting spring to support the upper top cover.
Compared with the prior art, the utility model has the following advantage:
1. can carry out freeze-thaw cycle tests under different rigidity constraint conditions
The utility model discloses in, through the selection of different rigidity restraint mechanisms, can provide different rigidity restraint change environment for the soil sample in the sample bucket, the mobility of cooperation ejector pin forms corresponding rigidity constraint condition (wait rigidity constraint condition, become rigidity constraint condition or constant volume constraint condition), the control by temperature change case realizes adjusting the soil sample temperature to the regulation and control of its inside temperature, and then realize the freeze-thaw cycle test under the different rigidity constraint condition, test data such as soil sample temperature, the salt expansion volume utilize test data detection component to obtain in the testing process.
The utility model discloses in, test data detection subassembly further includes displacement detection probe and/or pressure detector, and the vertical displacement volume of the ejector pin that displacement detection probe detected can reflect the salt inflation volume of soil sample among the test process, and the pressure value that pressure detector detected can reflect the salt inflation stress of soil sample. Of course, in practical application, the device also comprises a temperature detection probe for detecting the temperature of the soil sample in real time, and a temperature and humidity detector for monitoring the temperature and humidity inside the temperature control box in real time.
2. Can carry out dry-wet cycle test and dry-wet-freeze thawing coupling test under different rigidity constraint conditions
The utility model discloses in, furtherly, have the hole of permeating water on the top dish of soil sample top surface, add water filling port, weighing device, add water subassembly and air drying subassembly to the top cap can suitably leave the space of ladle body top edge air convection on the sample bucket, be used for realizing the dry and wet cycle test under the different rigidity constraint conditions, dry and wet-freeze thawing coupling test.
The mass water content change of the sample can be monitored in real time through the real-time weighing of the weighing device, compared with a humidity sensor, the monitoring result is not influenced by the ion content in the soil pore solution and the measurement precision of the sensor, and the measurement precision is high; the sample drying process adopts the air drying subassembly, accomplishes through the inside inner loop of box, need not carry out temperature control to circulating gas, and whole drying process does not disturb the soil body structure, and more accords with the operating condition.
3. The utility model discloses test device simple structure, the operation is simple and easy, and convenient assembling can simultaneous measurement sample salt bloated volume of in-process salt and salt power of expanding, the moisture content and the temperature variation of monitoring sample, and the automatic collection degree of data is high.
Drawings
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
Fig. 1 is an overall structure schematic diagram of the testing apparatus provided by the embodiment of the present invention.
Fig. 2 is a schematic structural diagram of the stiffness constraint mechanism provided in the embodiment of the present invention in the case of a rigid ring.
Fig. 3 is a schematic structural diagram of the stiffness constraint mechanism according to the embodiment of the present invention, in the case of a cylindrical spring.
Fig. 4 is a schematic structural diagram of the stiffness constraint mechanism provided in the embodiment of the present invention in the case of a tower spring.
Fig. 5 is a schematic structural diagram of a case where the stiffness constraint mechanism is not used according to an embodiment of the present invention.
In the figure:
1-temperature control box, 1 a-temperature controller, 1 b-circulating pipe, 1 c-top cover of temperature control box, 1 d-rotating shaft, 1 e-insulating layer;
2-a support frame, 2 a-an upper top plate, 2 b-a lower bottom plate and 2 c-a support rod;
3-sample barrel, 3 a-upper top cover, 3 b-lower bottom cover, 3 c-barrel body, 3 d-connecting rod;
4-rigid ring, 5-displacement sensor, 6-pressure detector, 7-monitoring computer, 8-temperature detector, 9-humidity detector, 10-radiation lamp, 11-weighing device, 12-constant temperature box, 13-first camera, 14-second camera, 15-parallel soil sample, 16-water pipe; 17-water adding component, 18-supporting plate, 19-spring, 20-spring supporting block, 21-temperature detecting probe, 22-soil sample, 23-top plate, 24-fixing block, 25-top rod, 26-displacement detecting probe, 27-water filling port, 28-first convex column, 29-second convex column, 30-column spring, 31-tower spring and 32-power-assisted pressure reducing rod.
Detailed Description
Referring to fig. 1 to 5, the utility model discloses in, rigidity restraint mechanism includes equal rigidity restraint mechanism, becomes rigidity restraint mechanism, through the selection of different rigidity restraint mechanisms (use still do not use, specifically use which under the circumstances of use), can provide different rigidity restraint change environment for soil sample 22 in sample bucket 3, and the mobility of cooperation ejector pin 25 forms corresponding rigidity constraint condition. Specifically, the case of using the stiffness constraint mechanism includes two limited stiffness constraint conditions (fig. 4) of an equal stiffness constraint condition (fig. 1 to 3) and a variable stiffness constraint condition, and the case of not using the stiffness constraint mechanism belongs to an infinite stiffness constraint condition, that is, a constant volume constraint condition (fig. 5).
In practical applications, the equal-stiffness constraint mechanism can be realized by using the rigid ring 4 shown in fig. 1-2 or the cylindrical spring 30 shown in fig. 3. The variable stiffness constraint mechanism can use springs with different stiffness variation forms (linear increase or linear decrease, or non-linear change in some function form) to achieve a variable stiffness condition, such as a tower spring 31 shown in fig. 4, which can achieve variable stiffness. The functional variants of the spring prior to assembly are known and can be directly analyzed. In addition, after a stress-deformation curve is drawn through the readings of the displacement detection probe 26 and the stress sensor 6, the change form of the stiffness coefficient can also be obtained according to the slope of the curve, and then the change form can also be compared with the inherent stiffness change of the spring.
The upper end and the lower end of the equal-rigidity constraint mechanism are provided with convex columns or concave columns, and the bottom of the upper top plate 2a of the support frame 2 and the top of the ejector rod 25 are provided with concave columns or convex columns which are matched with each other to realize insertion connection; the inner diameter of the concave column and the outer diameter of the convex column which are matched for use are mutually adaptive, and the connection stability is ensured. The simple and quick connection mode is convenient for the mounting, dismounting and replacement of the equal-rigidity constraint mechanism. It can be understood that, in order to realize the connection between the upper top plate 2a and the ejector rod 25 without using an equal rigidity constraint mechanism, the connecting columns at the bottom of the upper top plate 2a and the top of the ejector rod 25 are also concave-convex adapted to each other, and when necessary, the inside of one protruding column can be set into a hollow structure, so that the protruding column can play two functions of a concave column and a convex column.
The following description is mainly given for the case of equal stiffness constraint conditions, and the contents under other conditions are similar, and in practice, the corresponding stiffness constraint mechanism can be replaced.
Example 1 Freeze-thaw cycle test device under equal rigidity constraint conditions
Referring to fig. 1-2, the saline soil salt swelling characteristic test device under the constraint condition of equal rigidity mainly comprises a temperature control box 1, a support frame 2, a sample barrel 3, a rigid ring 4 and a test data detection assembly, wherein the support frame 2, the sample barrel 3 and the rigid ring 4 are all arranged inside the temperature control box 1.
The temperature control box 1 is used for regulating and controlling the internal temperature. The regulation and control mode is heat conduction, and the temperature control box 1 specifically comprises a box body, a circulating pipe 1b uniformly laid in the wall of the box body (except a top cover 1c of the temperature control box), circulating liquid in the circulating pipe 1b and a temperature controller 1a arranged outside the box body for regulating and controlling the temperature of the circulating liquid; the box body is provided with a temperature control box top cover 1c which can be opened and closed in a rotating mode through a rotating shaft 1d, and heat preservation layers 1e are laid inside the temperature control box top cover 1c and around a box wall internal circulation pipe 1 b.
The support frame 2 is provided with an upper top plate 2a and a lower bottom plate 2b, and the heights of the upper top plate and the lower bottom plate are always kept fixed in the test process. Specifically, the upper top plate 2a and the lower bottom plate 2b are supported and connected through a left support rod 2c and a right support rod 2c, the height between the two support rods depends on the height of the rigid ring 4, the sample barrel 3 and other parts after assembly, and the nuts on the support rods 2c are screwed to tightly abut against the upper surface of the upper top plate 2a after the height of the two support rods is adjusted to be proper; in addition, considering that a large stress exists between the upper top plate 2a and the lower bottom plate 2b in the test process under the constraint condition of constant volume, in order to relieve the stress and prevent the nut from loosening, a power-assisted pressure reducing rod 32 can be sleeved on the support rod 2c between the upper surface of the upper top plate 2a and the lower surface of the nut, and the upper end and the lower end of the power-assisted pressure reducing rod 32 adopt an outer diameter expanding structure. Further, the non-main holding portions of the upper top plate 2a and the lower bottom plate 2b are provided as a hollow structure to lighten the entire support frame 2.
On lower plate 2b was arranged in to sample bucket 3, the inside soil sample 22 of having put of sample bucket 3 during the experiment, the top dish 23 that the diameter suited with the internal diameter of sample bucket 3 has been placed to the top surface of soil sample 22, and the top surface of top dish 23 is equipped with ejector pin 25, and ejector pin 25 upwards extends through the last top cap 3a of sample bucket 3 and its ability is relative to last top cap 3a and reciprocates.
The sample barrel 3 comprises a barrel body 3c, an upper top cover 3a and a lower bottom cover 3b which are arranged at the upper end and the lower end of the barrel body, wherein the upper top cover 3a which is pressed tightly mainly seals the sample and prevents the evaporation of water in the humidifying process. The upper top cover 3a and the lower bottom cover 3b are connected through a plurality of connecting rods 3d, the part of the connecting rods 3d penetrating out of the upper top cover 3a is provided with external threads, and nuts used in a matched mode are arranged outside the external threads. The sample barrel 3 has simple structure and convenient assembly. Further, have the annular groove that carries out the screens to ladle body 3c on the lower bottom cover 3b, connecting rod 3d one end is fixed on lower bottom cover 3b, and the other end is up, during the assembly, places the annular groove on lower bottom cover 3b with ladle body 3c earlier, then corresponds trompil and connecting rod 3d on the upper top cover 3a and inserts, down falls in ladle body 3c upper edge, it can to compress tightly sealed to screw up the nut at last.
The rigid ring 4 is arranged between the top of the mandril 25 and the upper top plate 2a of the support frame 2, the rigidity coefficient of the rigid ring is selected and replaced according to the test requirement, the reference range is 200N/mm-5000N/mm, and the rigid ring 4 with different rigidity coefficients can be selected and replaced to provide environments with different rigidity coefficients for the test. In practical applications, the rigid ring 4 may be a simple rigid ring structure, or may be a force measuring ring. The common force measuring ring has two types of force display and displacement display, but displacement sensors are used in the implementation principle, for example, as shown in fig. 2, a displacement sensor 5 is arranged on the vertical diameter of the ring structure through a connecting part, and can detect the vertical deformation displacement of the ring structure; in practice, the displacement measured by the force loop can be compared and verified with the displacement measured by the displacement detection probe 26 to make reference to the determination of the accuracy of the test results.
The test data detection assembly is used for detecting test data in a test process and automatically transmitting the test data to the monitoring terminal 7, and specifically comprises a displacement detection probe 26 and/or a pressure detector 6 in practical application, wherein the displacement detection probe 26 is used for detecting the vertical displacement of the ejector rod 25 and reflecting the salt expansion amount generated by the soil sample 22 in the test process, and the pressure detector 6 is arranged between the top of the ejector rod 25 and the bottom of the rigid ring 4 and reflects the salt expansion stress generated by the soil sample 22 in the test process.
Assuming that the total height of the soil sample 22 is H and the deformation measured by the displacement detection probe 26 is H, the salt expansion ratio ξ is H/H, and assuming that the reading of the pressure detector 6 is F, the salt expansion force is σ F/aMedicine for treating rheumatismWherein A isMedicine for treating rheumatismThe clear area of the top disc 23 on the upper surface of the soil sample 22 in the sample barrel 3; in practice, theoretically, the equation σ ═ k × h/aMedicine for treating rheumatismThe salt expansion force can also be calculated, where k is the stiffness coefficient of the rigid ring 4 and h is the deformation, i.e., the salt expansion, measured by the displacement detection probe 26.
For the specific connection structure between the push rod 25, the pressure detector 6 and the rigid ring 4, specifically, the top of the push rod 25 has a first concave column (a hollow cylinder with an inner diameter equal to the diameter of the push rod 25 as shown in fig. 2), and the lower end of the rigid ring 4 has a first convex column 28; the pressure detector 6 is placed at the bottom of the cavity of the hollow cylinder, and the first protruding column 28 is inserted from the top of the hollow cylinder downward to directly or indirectly abut on the upper surface of the pressure detector 6. The connecting mode has the advantages of simple structure, convenient assembly and good stability. Correspondingly, the lower surface of the upper top plate 2a of the support frame 2 is provided with a second convex column 29, the top of the rigid ring 4 is provided with a second concave column which is matched with the second convex column 29, and the second convex column 29 is inserted into the second concave column to realize the connection of the two.
One end of a displacement detection probe 26 is provided on the jack 25 through the fixing block 24, and the other end extends upward through the upper lid 3a of the sample bucket 3 and is provided on the support plate 18 and fixed in position. In the test process, along with the vertical movement of the ejector rod 25, the length between the two ends of the displacement detection probe 26 is correspondingly changed, and a corresponding displacement variation quantity reflecting the salt expansion quantity is generated. The supporting plate 18 is horizontally disposed, and both ends of the supporting plate are sleeved on the portions of the two adjacent connecting rods 3d extending out of the upper top cover 3a through the snap rings.
Furthermore, the testing device of the utility model also comprises a temperature detecting probe 21, the probe of which is inserted into the soil sample 22 through the upper top cover 3a and the top disc 23 and is used for detecting the temperature value of the soil sample 22 in the testing process; it will be appreciated that the top plate 23 has a through hole through which the temperature sensing probe 21 passes, and that the up and down movement of the top plate 23 during the test does not affect the position of the temperature sensing probe 21. The device also comprises a temperature detector 8 arranged on the temperature control box 1 and used for detecting the internal temperature and a humidity detector 9 used for detecting the internal humidity.
The utility model discloses test device still includes on 1 inner wall of equipartition temperature control box, is located near a plurality of radiation lamps 10 of sample bucket 3 for simulate solar radiation environment.
In the test device of the utility model, the barrel body 3c of the sample barrel 3 is a transparent barrel body with a visual function, and can be made of acrylic material; the device also comprises a first camera 13 for shooting the soil sample 22 in the sample barrel 3, so that the specific form of the soil sample 22 in the test process can be visually monitored conveniently.
The utility model discloses test device is still including arranging temperature control box 1 inside parallel soil sample 15 in and carry out the second camera 14 of shooing to it. The parallel soil sample 15 is set for comparative analysis with the actual soil sample 22.
Example 2 Dry-Wet cycling, Dry-Wet-Freeze-thaw cycling test device under equal stiffness constraint conditions
Based on freeze-thaw cycle test device under the equal rigidity constraint condition that above-mentioned embodiment 1 discloses, refer to fig. 1 ~ 3, the utility model discloses still provide a dry wet cycle, dry wet-freeze-thaw cycle test device under equal rigidity constraint condition, specifically: the top disc 23 is provided with a plurality of water permeable holes, namely a porous top disc with the water permeable holes, the upper top cover 3a of the sample barrel 3 is uniformly provided with a plurality of water injection ports 27, and the distance between the water injection ports and the upper edge of the barrel body 3c can be finely adjusted; the device also comprises a weigher 11, a water adding assembly 17 and an air drying assembly.
It should be noted here that in the freeze-thaw cycle test apparatus in example 1, the top tray 23 may be a solid top tray without water permeable holes or a porous top tray with water permeable holes, and all of the freeze-thaw cycle test processes can be completed. However, since the freeze-thaw cycle test itself does not require water permeable holes and there may be a problem that the soil sample is squeezed out of the holes when the soil sample is thawed, the freeze-thaw cycle test preferably uses a solid top tray from the viewpoint of ensuring the best test effect.
The weigher 11 is arranged below the support frame 2, and the mass water content change of the soil sample 22 can be monitored in real time through real-time weighing. Further, in order to avoid the influence of the temperature change in the temperature control box 1 on the accuracy of the weighing device 11, the weighing device 11 may be arranged inside the thermostat 12, and the temperature inside the thermostat 12 may be set at normal temperature.
The water adding assembly 17 is arranged outside the temperature control box 1 and supplies water to the water filling port 27 through a water pipe 16 penetrating the wall of the temperature control box 1. The water adding assembly 17 specifically comprises a water tank, a low-pressure pipe, a water adding pump and a high-pressure pipe which are connected in sequence, wherein the high-pressure pipe is connected with the water pipe 16; wherein, add the water pump and specifically adopt the peristaltic pump and it can control the interval of adding water and the volume of adding water of every turn to realize adding the automated control of water volume.
The air drying assembly (not shown in the figure) comprises an air duct, an air circulator and an air dehumidifier, wherein the air inlet and the air outlet of the air drying assembly are communicated with the interior of the temperature control box 1, and the air circulator and the air dehumidifier are arranged on the air duct. Wherein, the realization of the air circulator and the air dehumidifier just refers to the prior relevant technology.
Further, the distance between the upper top cover 3a of the sample barrel 3 and the upper edge of the barrel body 3c can be finely adjusted, and the implementation means can be as follows: an adjusting spring 19 supporting block is arranged at the position of the connecting rod 3d close to the bottom surface of the upper top cover 3a, and an adjusting spring 19 is sleeved between the spring supporting block 20 and the upper top cover 3 a; the gap between the upper lid 3a and the upper edge of the tub 3c is achieved by screwing the nut so that the adjusting spring 19 supports the upper lid 3 a.
In the above embodiments 1 and 2, the test data detection components such as the displacement detection probe 26, the pressure detector 6, the temperature detector 8, the humidity detector 9, the first camera 13, and the weighing device 11 are finally collected (preferably, data is transmitted by wireless communication) to the monitoring terminal 7 by respective data collectors, so as to realize automatic collection and real-time monitoring of test data.
Based on the testing device disclosed in the above embodiment, the following contents of the present invention explain the testing operation process in its practical application. Wherein, the displacement detection probe 26 is a displacement sensor with the range of 0-50 mm and the precision of +/-0.01 mm; the temperature detection probe 21 and the temperature detector 8 specifically use temperature sensors with the accuracy of +/-0.01 ℃; the pressure monitor 6 adopts a pressure sensor with the precision of +/-0.001 kN, and the weighing device 11 adopts a pressure sensor with the precision of +/-0.01 g.
Example 3 Freeze-thaw cycle test protocol under equal stiffness constraints
(1) Preparing a sample: weighing the soil and the content of soluble salt required by sample loading, placing the soil sample in a curing box for curing for 48h after the soil sample is well mixed, and then compacting and molding the soil sample in a sample making device by using a jack to form the soil sample 22.
(2) Assembling the device: and (3) smearing a layer of vaseline on the inner wall of the sample barrel 3 for reducing the lateral restraint of the inner wall of the sample barrel 3 on the expansion of the soil sample, pressing the soil sample 22 into the sample barrel 3, and finishing the assembly of the whole device and the preparation work before the test based on the device disclosed in the embodiment 1. The top disk 23 on the upper surface of the soil sample 22 in the sample barrel 3 is preferably a solid top disk without water permeable holes, the upper top cover 3a and the barrel body 3c of the sample barrel 3 are always kept in a pressing and sealing state, and each test data acquisition end is connected to the monitoring computer 7 through respective data acquisition instruments.
(3) Freeze-thaw cycle testing: the temperature controller 1a is used for adjusting the temperature in the temperature control box 1, so that the temperature of the soil sample 22 is adjusted, and a freeze-thaw cycle test is carried out.
The temperature cycle can be as follows: 26 ℃→ 21 ℃ → 16 → 11 → 6 ℃ → 1 → -4 → -9 ℃ → -19 → -24 ℃ → -19 → -14 ℃ → -9 → -4 ℃ → 1 ℃ → 6 → 11 ℃ → 16 → 21 → 26 ℃.
In the test process, the salt expansion force of the soil sample 22 is monitored by the pressure detector 6, the salt expansion amount is detected by the displacement detection probe 26, the temperature of the sample is measured by the temperature detection probe 21, and the temperature and the humidity in the temperature control box 1 are measured by the temperature detector 8 and the humidity detector 9; and the data of each test data acquisition end is connected to a computer through a data acquisition instrument for real-time monitoring. The concrete morphology of the soil sample 22 and the parallel soil sample 15 under the action of the freeze-thaw cycle is observed through the first camera 13 and the second camera 14.
(4) And 7-8 groups of rigid rings 4 with different rigidity coefficients are arranged in each group of tests by replacing the rigid rings 4 with different rigidity coefficients, and the steps are repeated to perform the tests on the freeze-thaw cycle salt expansion characteristics of the saline soil under the constraint condition of equal rigidity.
Example 4 Dry and Wet cycling test procedure under equal stiffness constraint conditions
(1) Preparing a sample: the same as in example 3.
(2) Assembling the device: based on the device disclosed in example 2, the assembly of the entire device and the preparation before testing were completed. Wherein, the top plate 23 on the upper surface of the soil sample 22 in the sample barrel 3 is a porous top plate with water permeable holes, and the upper top cover 3a of the sample barrel 3 is tightly pressed and sealed with the barrel body 3c by screwing the nut on the connecting rod 3 d. The rest is the same as example 3.
(3) Dry-wet cycle test: the dry-wet cycle salt expansion characteristic test (under the temperature control condition) of the saline soil under the constraint condition of equal rigidity is divided into two stages: a quantitative humidification stage and a water content decreasing stage.
(31) A quantitative humidification stage: setting the water adding amount of the water adding 17c in the water adding assembly 17 (for example, the water adding amount is 1% of the water content of the sample once), setting the temperature of the temperature controller 1a in the temperature control box 1 (for example, 20 ℃ under the constant temperature condition), stabilizing for 4h, starting to add water into the soil sample after the temperature in the temperature control box 1 is constant, and enabling the water to flow into the water injection port 27 on the upper top cover 3a through the water adding assembly 17 and the water pipe 16 and then flow into the soil sample 22 through the opening on the porous top disc.
(32) A stage of decreasing the water content: make and have appropriate clearance (unscrew the nut on connecting rod 3d) between top cap 3a and ladle body 3c upper edge, utilize regulating spring 19 to bounce top cap 3a), close and add water subassembly 17, open the air drying subassembly, through the convection current circulation of air, the air drying subassembly is constantly dried the moisture of effusion in the soil sample 22, reduces the air humidity in the temperature control case 1 to the moisture content to soil sample 22 subtracts progressively.
In the test process, the mass water content of the soil sample 22 is monitored through the weighing device 11, the salt expansion force is monitored through the pressure detector 6, the salt expansion amount is detected through the displacement detection probe 26, and the data of each test data acquisition end is connected to a computer through the data acquisition instrument for real-time monitoring.
(4) And (3) replacing the rigid rings 4 with different rigidity coefficients, setting 7-8 groups of rigid rings 4 with different rigidity coefficients in each group of tests, setting different environmental temperatures (the temperature setting range is 0-38 ℃, repeating the steps (1) - (3), and performing the saline soil dry-wet cycle salt expansion characteristic test under the constraint condition of equal rigidity.
Example 5 Dry-Wet-Freeze-thaw coupling test procedure under equal stiffness constraint
(1) Preparing a sample: the same as in example 4.
(2) Assembling the device: based on the device disclosed in example 2, the assembly of the entire device and the preparation before testing were completed. Wherein, the top disc 23 on the upper surface of the soil sample 22 in the sample barrel 3 is a porous top disc with water permeable holes, and a proper distance is provided between the upper top cover 3a and the barrel body 3c of the sample barrel 3. The rest is the same as example 4.
(3) Dry-wet-freeze-thaw test: the temperature controller 1a is used for adjusting the temperature in the temperature control box 1, the water adding component 17 is used for supplementing water, the air drying component is used for drying, and the three steps are carried out simultaneously.
The specific test conditions may be: the water content variation range is as follows: 26% → 24% → 22% → 20% → 18% → 16% → 14% → 12% → 10% → 8% → 6% → 8% → 10% → 12% → 14% → 16% → 18% → 20% → 22% → 24% → 26% → 28%; the corresponding temperature adjusting range is as follows: 26 ℃→ 21 ℃ → 16 → 11 ℃ → 6 ℃ → 1 ℃ → 6 → 11 ℃ → 16 → 21 ℃ → 26 ℃.
The monitoring process during the test was the same as in example 4.
(4) And 7-8 groups of rigid rings 4 with different rigidity coefficients are arranged in each group of tests by replacing the rigid rings 4 with different rigidity coefficients, and the steps are repeated to perform the saline soil dry-wet-freeze thawing coupling salt expansion characteristic test under the constraint condition of equal rigidity.
The technical scheme provided by the utility model is introduced in detail above. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the structure and core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.
Claims (10)
1. The utility model provides a saline soil salt swelling characteristic test device under rigidity restraint condition which characterized in that, the device includes:
the device comprises a temperature control box (1), a support frame (2), a sample barrel (3), a rigidity constraint mechanism and a test data detection assembly, wherein the support frame (2), the sample barrel (3) and the rigidity constraint mechanism are all arranged in the temperature control box (1);
the temperature control box (1) is used for regulating and controlling the internal temperature;
the supporting frame (2) is provided with an upper top plate (2a) and a lower bottom plate (2b), and the heights of the upper top plate and the lower bottom plate are fixed in the test process;
the sample barrel (3) is arranged on the lower bottom plate (2b), a soil sample (22) is placed in the sample barrel (3) during testing, a top plate (23) with the diameter matched with the inner diameter of the sample barrel (3) is placed on the top surface of the soil sample (22), an ejector rod (25) is arranged on the top surface of the top plate (23), and the ejector rod (25) extends upwards to extend through an upper top cover (3a) of the sample barrel (3) and can move up and down relative to the upper top cover (3 a);
the rigidity constraint mechanism comprises an equal rigidity constraint mechanism or a variable rigidity constraint mechanism, the equal rigidity constraint mechanism or the variable rigidity constraint mechanism is selected to be used or not used according to the actual rigidity constraint requirement, and correspondingly formed rigidity constraint conditions comprise an equal rigidity constraint condition, a variable rigidity constraint condition or a constant volume constraint condition; the rigidity restraining mechanism is arranged between the top of the ejector rod (25) and the upper top plate (2a) when in use, and the top of the ejector rod (25) is directly connected with the upper top plate (2a) when not in use;
the test data detection assembly is used for detecting test data in the test process and transmitting the test data to the monitoring terminal.
2. The apparatus according to claim 1, wherein the test data detection assembly comprises a displacement detection probe (26) and/or a pressure detector (6), the displacement detection probe (26) is used for detecting the vertical displacement of the ejector pin (25), and the pressure detector (6) is arranged between the top of the ejector pin (25) and the bottom of the rigidity constraint mechanism or between the top of the ejector pin (25) and the bottom of the upper top plate (2 a).
3. The apparatus according to claim 2, wherein the displacement detecting probe (26) is provided on the lift pin (25) through a fixing block (24) at one end and on the support plate (18) at the other end extending upward through an upper top cover (3a) of the sample bucket (3).
4. Device according to claim 1, characterized in that said equal stiffness constraint means are embodied as a rigid ring (4) or a cylindrical spring (30) and said variable stiffness constraint means are embodied as a tower spring (31).
5. The device as claimed in claim 1, wherein the upper and lower ends of the equal rigidity constraint mechanism are provided with convex columns or concave columns, and the bottom of the upper top plate (2a) of the support frame (2) and the top of the top rod are provided with concave columns or convex columns which are matched with each other to realize insertion connection.
6. The device according to claim 5, characterized in that the top of the ejector pin (25) has a first concave column, and the lower end of the equal stiffness constraint mechanism has a first convex column; the bottom of the cavity of the first concave column is provided with a pressure detector (6), and the first convex column is inserted downwards from the top of the first concave column and directly or indirectly propped against the upper surface of the pressure detector (6).
7. The device according to claim 1, characterized in that it further comprises a temperature detection probe (21), the probe of which is inserted into the soil sample (22) through the upper cover (3a) and the top plate (23) for detecting the temperature value of the soil sample (22) during the test; and/or the device also comprises a plurality of radiation lamps (10) which are uniformly distributed on the inner wall of the temperature control box (1) and are positioned near the sample barrel (3).
8. The device according to claim 1, characterized in that the barrel (3c) of the sample barrel (3) is a transparent barrel, the device further comprising a first camera (13) for taking a picture of the soil sample (22) in the sample barrel (3); and/or the device also comprises a parallel soil sample (15) arranged inside the temperature control box (1) and a second camera (14) for shooting the parallel soil sample.
9. The apparatus of any one of claims 1 to 8, wherein: a water permeable hole is formed in the top disc (23), a plurality of water injection ports (27) are formed in an upper top cover (3a) of the sample barrel (3), and the distance between the water injection ports and the upper edge of the barrel body (3c) can be finely adjusted; the device further comprises a weighing device (11), a water adding assembly (17) and an air drying assembly, wherein the weighing device (11) is arranged below the support frame (2), the water adding assembly (17) is arranged outside the temperature control box (1) and provides a water source for the water filling port (27) through a water pipe (16) penetrating through the wall of the temperature control box (1), and the air drying assembly comprises an air inlet, an air outlet, an air pipeline, an air circulator and an air dehumidifier, wherein the air inlet and the air outlet are communicated with the inside of the temperature control box (1), and the air circulator and the air dehumidifier are arranged on the air pipeline.
10. The device according to claim 9, wherein the sample barrel (3) comprises a barrel body (3c) and the upper top cover (3a) and the lower bottom cover (3b) which are arranged at the upper end and the lower end of the barrel body, the upper top cover (3a) and the lower bottom cover (3b) are connected through a plurality of connecting rods (3d), the part of the connecting rod (3d) penetrating out of the upper top cover (3a) is provided with external threads, and the external threads are externally provided with nuts which are matched; an adjusting spring (19) supporting block is arranged at the position, close to the bottom surface of the upper top cover (3a), of the connecting rod (3d), and an adjusting spring (19) is sleeved between the spring supporting block (20) and the upper top cover (3 a); the gap between the upper top cover (3a) and the upper edge of the barrel body (3c) is realized by screwing the nut to enable the adjusting spring (19) to support the upper top cover (3 a).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920833397.0U CN210665725U (en) | 2019-06-04 | 2019-06-04 | Saline soil salt expansion characteristic test device under rigidity constraint condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920833397.0U CN210665725U (en) | 2019-06-04 | 2019-06-04 | Saline soil salt expansion characteristic test device under rigidity constraint condition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210665725U true CN210665725U (en) | 2020-06-02 |
Family
ID=70815597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920833397.0U Active CN210665725U (en) | 2019-06-04 | 2019-06-04 | Saline soil salt expansion characteristic test device under rigidity constraint condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210665725U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110082508A (en) * | 2019-06-04 | 2019-08-02 | 中国科学院寒区旱区环境与工程研究所 | The swollen characteristic test apparatus of salt marsh earth salt under the conditions of a kind of deflection constraint |
| CN111855735A (en) * | 2020-08-06 | 2020-10-30 | 兰州理工大学 | Efficient and accurate measuring device for salt expansion and frost heaving of salt solution |
| CN113504356A (en) * | 2021-07-12 | 2021-10-15 | 安徽省公路桥梁工程有限公司 | Simple equipment for sampling and detecting swelling strength of swelling soil |
-
2019
- 2019-06-04 CN CN201920833397.0U patent/CN210665725U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110082508A (en) * | 2019-06-04 | 2019-08-02 | 中国科学院寒区旱区环境与工程研究所 | The swollen characteristic test apparatus of salt marsh earth salt under the conditions of a kind of deflection constraint |
| CN111855735A (en) * | 2020-08-06 | 2020-10-30 | 兰州理工大学 | Efficient and accurate measuring device for salt expansion and frost heaving of salt solution |
| CN113504356A (en) * | 2021-07-12 | 2021-10-15 | 安徽省公路桥梁工程有限公司 | Simple equipment for sampling and detecting swelling strength of swelling soil |
| CN113504356B (en) * | 2021-07-12 | 2023-08-22 | 安徽省公路桥梁工程有限公司 | Simple equipment for detecting expansion strength by sampling expansive soil |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN210665725U (en) | Saline soil salt expansion characteristic test device under rigidity constraint condition | |
| CN110082508A (en) | The swollen characteristic test apparatus of salt marsh earth salt under the conditions of a kind of deflection constraint | |
| CN202562912U (en) | Layered temperature controlling soil freezing and thawing cycle test device | |
| CN105823716B (en) | The experimental rig observed in real time in Rock And Soil crack is carried out under the conditions of Observation of The Suction | |
| CN104460788B (en) | Constant temperature and constant humidity deformeter | |
| CN110426337B (en) | Rock-soil body osmotic deformation testing device under low stress condition and testing method thereof | |
| CN110455853B (en) | Comprehensive testing device for crystallization pressure and frost heaving salt expansion of saline soil | |
| CN110132833A (en) | It is a kind of can real-time measurement high-concentration tailings moisture evaporation drying performance experimental provision | |
| CN106370816A (en) | Testing system capable of dynamically testing soil dehumidification/freezing water content change features | |
| CN103823040B (en) | A kind of soil body of simulating is by the device of extreme climate effect and the method using this device to test | |
| CN110296889A (en) | Pressure chamber and its test method for coarse grain soil large-scale Frozen-thawed cycled triaxial test | |
| CN106442617A (en) | Method and device for measuring thermal storage efficiency of sheet material | |
| CN109709278A (en) | A kind of experimental rig and method for simulating in situ environment strength of filling mass forming process | |
| CN114544717A (en) | ECT quantitative monitoring water transmission method | |
| CN109765259B (en) | Method and device for determining upper limit change rule of frozen soil based on soil water and salt change | |
| CN202133659U (en) | Experimental device for monitoring swelling-shrinkage deformation of deep soil under influence of hot rainy weather | |
| CN211014081U (en) | Saline soil freeze-thaw cycle test device under constant-rigidity boundary condition | |
| CN112540026B (en) | Temperature-control unsaturated triaxial apparatus water-vapor separation collecting and monitoring device and application system thereof | |
| CN113791201A (en) | Multifunctional concrete expansion rate detection device | |
| CN113820313A (en) | Deformation testing system and method for cohesive soil in moisture desorption process | |
| CN113866080A (en) | Test device and test method for simulating salt corrosion damage of porous medium material | |
| LU501271B1 (en) | Experimental device capable of measuring water evaporation drying property of high-concentration tailings in real time | |
| CN113790995A (en) | Test device and method for measuring unsaturated soil-water characteristic curve | |
| CN113109382A (en) | Soil mass freezing and thawing device with multi-dimensional dynamic sensing function | |
| CN207798431U (en) | A kind of environmental suitability test device of structural member and health monitoring equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200713 Address after: 730000 No.318, Donggang West Road, Chengguan District, Lanzhou City, Gansu Province Patentee after: NORTHWEST INSTITUTE OF ECO-ENVIRONMENT AND RESOURCES, CAS Address before: 730000 Gansu city of Lanzhou province Donggang West Road No. 320 Patentee before: Institute of environment and Engineering in cold and dry areas, Chinese Academy of Sciences |