CN116429815A - Equipment and method for testing interaction characteristic influence of frozen soil and concrete - Google Patents

Equipment and method for testing interaction characteristic influence of frozen soil and concrete Download PDF

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Publication number
CN116429815A
CN116429815A CN202310058730.6A CN202310058730A CN116429815A CN 116429815 A CN116429815 A CN 116429815A CN 202310058730 A CN202310058730 A CN 202310058730A CN 116429815 A CN116429815 A CN 116429815A
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China
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concrete
soil
frozen soil
temperature
frozen
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龚廷民
阳斌
张九宇
徐姣姣
王远志
赵江波
周倩
徐德帆
付玉龙
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China Railway Engineering Equipment Group Co Ltd CREG
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China Railway Engineering Equipment Group Co Ltd CREG
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Priority to CN202310058730.6A priority Critical patent/CN116429815A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/14—Investigating or analyzing materials by the use of thermal means by using distillation, extraction, sublimation, condensation, freezing, or crystallisation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
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  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

The utility model discloses a testing device and a testing method for the mutual characteristic influence of frozen soil and concrete, and solves the technical problems that the influence between the concrete and the frozen soil characteristics cannot be explored and the optimal working temperature of the concrete which does not influence the stability of the frozen soil cannot be found in the prior art. The testing equipment comprises an outer shell and an inner shell which are arranged in a nested manner, a soil sample filling cavity is formed between the outer shell and the inner shell, a space surrounded by the inner wall of the soil sample is a concrete filling cavity, and a refrigerating unit and a temperature measuring unit are arranged in the soil sample filling cavity. According to the technical scheme, a soil sample is filled in a soil sample filling cavity, a refrigerating unit is utilized for refrigerating, so that the filled soil sample is changed into frozen soil, and the frozen soil environment in tunnel construction is simulated; filling concrete into the concrete filling cavity, detecting the temperature change of the frozen soil through the temperature measuring unit, monitoring the change of the frozen soil and the equal strength process of the concrete through observation, and comparing and selecting the concrete temperature suitable for practical engineering application through repeated experiments.

Description

Equipment and method for testing interaction characteristic influence of frozen soil and concrete
Technical Field
The utility model relates to the technical field of frozen soil and concrete testing, in particular to testing equipment and a testing method for the mutual characteristic influence of frozen soil and concrete.
Background
Frozen soil is a kind of rock and soil with temperature lower than 0 deg.c and ice, and for construction engineering, frozen soil is poor foundation soil and is easy to produce frost heaving and thawing. When a shield method is used for tunneling tunnels, and gaps between segments and tunnels are backfilled in an excavated region, concrete is in direct contact with frozen soil, and once improper treatment measures are taken, adverse effects are caused on engineering. Because the best equal-strength temperature of the concrete is in the range of 15-20 ℃, heat transfer can occur in the process of contacting with the frozen soil, so that the temperature of the frozen soil in a certain area in the radial direction of the tunnel is increased, the frozen soil is thawed down, the ground is settled or even collapsed in severe cases, and the support in the tunnel is damaged to a certain extent. However, if the temperature of the concrete is too low, the equal-strength process can be seriously slowed down, the bolt connection of the circular seams of the segments is affected, the integral strength and the waterproof effect of the tunnel segments are further affected, and the construction period of the whole tunnel can be prolonged.
At present, less research is carried out on the influence of equal strength of concrete and thawing and sinking of frozen soil, and most of the structures directly utilize a new supporting structure or method, such as a tunnel supporting structure suitable for a high-temperature permafrost region, which is provided with three layers of structures from outside to inside, namely primary concrete spraying supporting, primary concrete lining building and secondary concrete lining building, and system anchor rods are cancelled; an annular drain pipe is arranged between the primary shotcrete support and the primary molded concrete lining; a fully-closed heat insulation layer is arranged between the primary molded concrete lining and the secondary molded concrete lining; the heat insulation layer and the heat preservation plate are arranged on the inner surface of the secondary molding concrete lining, the whole structure is complex, and the influence of the concrete temperature on the characteristic of frozen soil is directly ignored.
Through cross-field search, the Chinese patent application with application publication number of CN 114935586A and application publication number of 2022.08.23 discloses a frozen soil pile foundation hydration thermal simulation test device and a test method, wherein the test device comprises an aluminum pipe for simulating a pile foundation and a temperature controller for adjusting temperature, an electric heating rod is arranged in the aluminum pipe, a quartz sand particle layer and a temperature sensor for detecting the surface temperature of the aluminum pipe are arranged on the outer surface of the aluminum pipe, the output end of the temperature controller is connected with a solid-state relay, and the electric heating rod is connected with the solid-state relay.
Although the technical scheme of the utility model is applied to a frozen soil pile foundation hydration thermal simulation test, the concrete hydration heat release and temperature rise process and the freezing return process can be simulated, and the total heat release of different pile foundations can be simulated, the technical scheme and the utility model aim to explore the influence of temperature on the change of the bearing capacity of the pile foundations and to find out the problem of the optimal bearing capacity of different pile foundations under the heat release. However, the method cannot be used in the field of tunnel support, the influence between the concrete and the characteristics of the frozen soil cannot be explored, and the optimal working temperature of the concrete which does not influence the stability of the frozen soil cannot be found.
Therefore, it is necessary to design an apparatus and method to test the effect between the concrete and the characteristics of the frozen soil to find the optimal working temperature of the concrete without affecting the stability of the frozen soil.
Disclosure of Invention
Aiming at the defects in the background technology, the utility model provides a testing device and a testing method for the mutual characteristic influence of frozen soil and concrete, and solves the technical problems that the influence between the concrete and the frozen soil characteristics cannot be explored and the optimal working temperature of the concrete which does not influence the stability of the frozen soil cannot be found in the prior art.
The technical scheme of the application is as follows:
the utility model provides a test equipment that frozen soil and concrete mutual characteristic influence, includes the shell body, the inside casing of nested setting, is the soil body sample between shell body and the inside casing and fills the chamber, and the space that the soil body sample inner wall encloses is the concrete and fills the chamber, be provided with refrigeration unit and temperature measurement unit in the soil body sample fills the chamber. According to the technical scheme, a soil sample is filled in a soil sample filling cavity, a refrigerating unit is utilized for refrigerating, so that the filled soil sample is changed into frozen soil, and the frozen soil environment in tunnel construction is simulated; and filling concrete into the concrete filling cavity, detecting the temperature change of the frozen soil through a temperature measuring unit, monitoring the change of the frozen soil and the equal strength process of the concrete through observation, and comparing and selecting the concrete temperature suitable for practical engineering application through repeated experiments.
Further, an inner shell is nested in the inner shell, and a concrete filling cavity is arranged between the soil body sample and the inner shell. The section of the concrete filling cavity in the technical scheme is circular, and the section of the concrete filling cavity in the technical scheme is annular, so that the concrete during lining of a tunnel in tunnel construction can be further simulated.
Further, the inner shell is a small cylinder, and the section of the concrete filling cavity in the technical scheme is circular.
Further, the refrigerating unit comprises a cooling pipe arranged in the soil body sample filling cavity, and the cooling pipe is connected with the liquid nitrogen cooling system. According to the technical scheme, the liquid nitrogen is used for refrigerating, so that the refrigerating efficiency is high, the liquid nitrogen can be rapidly circulated, the soil in the soil sample filling cavity can be rapidly frozen, and the temperature distribution of each position is uniform and stable.
Further, the cooling pipe is arranged in a spiral mode along the length direction of the inner shell, so that the efficiency of manufacturing the frozen soil can be further improved, the uniformity and stability of the temperature distribution of the frozen soil can be further guaranteed, and the frozen soil in actual construction can be simulated to the greatest extent.
Further, the temperature measuring unit comprises a temperature sensor arranged in the soil body sample filling cavity, and the temperature detected by the temperature sensor is collected through the acquisition instrument to continuously monitor the temperature change of the frozen soil.
Further, the outer shell is an outer cylinder, the inner shell is a large cylinder, the outer cylinder, the large cylinder and the small cylinder are coaxially arranged, and the left side door and the right side door are respectively arranged at two ends of the outer cylinder, the large cylinder and the small cylinder.
Further, the two ends of the outer cylinder or/and the big cylinder or/and the small cylinder are respectively provided with a left side door and a right side door which are detachably connected.
Further, the temperature sensor is arranged on a sensor support, the sensor support is provided with a plurality of rings along the axis of the outer cylinder, each ring comprises a plurality of sensor supports which are arranged around the axis of the outer cylinder at equal angles, and each sensor support is vertically connected to the inner wall of the outer cylinder.
Further, at least two temperature sensors are arranged on each sensor support, and each temperature sensor on the sensor support is arranged in the length direction of the sensor support along the diameter direction of the outer cylinder.
Further, the shell body is detachably connected with a transparent side door, and the change of frozen soil and concrete can be directly observed through the side door.
Further, a concrete injection pipe corresponding to the concrete filling cavity is arranged on the side door.
Further, the outer housing and the inner housing have a diameter difference that is substantially greater than the diameter difference of the inner housing and the inner housing.
Further, the outer wall of the outer shell is connected with a support, and when the support is supported on the ground, the outer shell is transversely placed relative to the ground.
A method for testing the interaction of frozen soil and concrete, comprising the testing device for the interaction of frozen soil and concrete according to any one of the above, the testing method comprising the following steps:
firstly filling a soil sample in a soil sample filling cavity, then freezing the soil sample in the soil sample filling cavity through a refrigerating unit, then disassembling an inner shell, injecting concrete into the concrete filling cavity, measuring the temperature of each point in the soil sample filling cavity through a temperature measuring unit, observing the thawing phenomenon and state change of the soil and the equal strength process of the concrete, adopting the concrete with different temperatures to carry out a repeatability experiment, recording the equal strength time of the concrete and the temperature of each point in the soil sample filling cavity at the moment, and selecting the concrete temperature suitable for practical engineering application through comparison.
Further, firstly, the outer shell, the inner shell and the right side door are connected, the testing equipment is placed down to the right side door to land, a soil body sample is added between the outer shell and the inner shell, after the soil body sample is filled up, the left side door is connected with the outer shell, then the testing equipment is restored to the original position, liquid nitrogen is introduced into the testing equipment through the cooling pipe, the soil body in the soil body sample filling cavity is frozen, after the soil body reaches a frozen soil state, the left side door and the inner shell are removed, the side door is connected with the outer shell, then concrete with a certain temperature is injected between the inner shell and the frozen soil through the concrete injection pipe, after the concrete is filled up, the temperature of each point of the frozen soil is measured through the temperature sensor, the process of thawing phenomenon, state change, concrete and the like of the soil body is directly observed on one side of the side door, repeated experiments are carried out by using concrete with different temperatures, the time of the concrete and the like and the temperature of each point of the frozen soil at the moment are recorded, and the concrete temperature suitable for practical engineering application is selected through comparison.
Further, a single variable is controlled to test, the temperature of the concrete injected into the concrete filling cavity is unchanged, accelerator with different proportions is added into the concrete, then the temperature change of the frozen soil at different positions in the axial direction and the radial direction is collected through a temperature sensor and a collecting instrument, and finally, under the condition that the adding proportion of the accelerator is determined, the influence area of concrete heat release on surrounding frozen soil is minimum and the influence time is shortest.
Compared with the prior art, the testing equipment and the testing method for the mutual characteristic influence of the frozen soil and the concrete, disclosed by the utility model, fill the blank of researching the equal strength of the concrete and the thawing and sinking influence of the frozen soil in the prior art, therefore, the scheme can simulate the equal strength process of the concrete under the frozen soil in a tunnel lining indoors, monitor the state of the frozen soil and the equal strength process of the concrete in various aspects, and find the concrete working temperature most suitable for engineering practice through repeated experiments.
Drawings
In order to more clearly illustrate the embodiments of the present utility model, the drawings that are required for the description of the embodiments will be briefly described below, it being apparent that the drawings in the following description are only some embodiments of the present utility model and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a front view of a test apparatus according to the present utility model;
FIG. 2 is a right side view of the test apparatus of the present utility model;
FIG. 3 is a schematic view of a cooling tube and sensor holder arrangement in the test apparatus of FIG. 2;
the meaning of the symbols in the drawings is as follows:
an outer cylinder 1, a cooling pipe 2, a sensor bracket 3, a temperature sensor 4, a large cylinder 5, a small cylinder 6, a side door 7, a left side door 8, a right side door 9 and a concrete injection pipe 10.
Detailed Description
The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without any inventive effort, are intended to be within the scope of the utility model.
The utility model provides a test equipment that frozen soil and concrete mutual characteristic influence, includes the shell body, the inside casing of nested setting, is the soil body sample between shell body and the inside casing and fills the chamber, and the space that the soil body sample inner wall encloses is the concrete and fills the chamber, be provided with refrigeration unit and temperature measurement unit in the soil body sample fills the chamber. According to the technical scheme, a soil sample is filled in a soil sample filling cavity, a refrigerating unit is utilized for refrigerating, so that the filled soil sample is changed into frozen soil, and the frozen soil environment in tunnel construction is simulated; and filling concrete into the concrete filling cavity, detecting the temperature change of the frozen soil through a temperature measuring unit, monitoring the change of the frozen soil and the equal strength process of the concrete through observation, and comparing and selecting the concrete temperature suitable for practical engineering application through repeated experiments.
As a preferred implementation mode of the testing equipment for the influence of the mutual characteristics of the frozen soil and the concrete, an inner shell is nested in the inner shell, and a concrete filling cavity is arranged between the soil body sample and the inner shell. The section of the concrete filling cavity in the technical scheme is circular, and the section of the concrete filling cavity in the technical scheme is annular, so that the concrete during lining of a tunnel in tunnel construction can be further simulated.
As a preferred embodiment of the testing device for the influence of the mutual characteristics of the frozen soil and the concrete, as shown in fig. 1, the inner shell is a small cylinder 6, and the section of the concrete filling cavity in the technical scheme is circular, so that the concrete pouring shape during tunnel construction can be completely simulated.
As a preferred embodiment of the testing device for the mutual property influence of the frozen soil and the concrete, the refrigerating unit comprises a cooling pipe 2 arranged in the soil body sample filling cavity, and the cooling pipe 2 is connected with a liquid nitrogen cooling system. According to the technical scheme, the liquid nitrogen is used for refrigerating, so that the refrigerating efficiency is high, the liquid nitrogen can be rapidly circulated, the soil in the soil sample filling cavity can be rapidly frozen, and the temperature distribution of each position is uniform and stable.
As the preferred implementation mode of the test equipment for the influence of the mutual characteristics of the frozen soil and the concrete, as shown in fig. 3, the cooling pipe 2 is spirally arranged along the length direction of the inner shell, so that the efficiency of frozen soil manufacturing can be further improved, the uniformity and stability of the temperature distribution of the frozen soil can be further ensured, and the frozen soil in actual construction can be simulated to the maximum extent.
As the preferred implementation mode of the testing equipment for the mutual property influence of the frozen soil and the concrete, the temperature measuring unit comprises a temperature sensor 4 arranged in the soil body sample filling cavity, and the temperature detected by the temperature sensor 4 is collected by the acquisition instrument so as to continuously monitor the temperature change of the frozen soil.
As a preferred embodiment of the testing device for the mutual influence of the frozen soil and the concrete, as shown in fig. 1, the outer shell is an outer cylinder 1, the inner shell is a large cylinder 5, the outer cylinder 1, the large cylinder 5 and the small cylinder 6 are coaxially arranged, and the left side door 8 and the right side door 9 are respectively arranged at two ends of the outer cylinder.
Further, two ends of the outer cylinder 1 or/and the large cylinder 5 or/and the small cylinder 6 are respectively provided with a left side door 8 and a right side door 9 which are detachably connected.
As a preferred embodiment of the testing device for the mutual influence of the characteristics of the frozen soil and the concrete, as shown in fig. 1 and 3, the temperature sensor 4 is arranged on the sensor support 3, the sensor support 3 is provided with a plurality of rings along the axis of the outer cylinder 1, each ring comprises a plurality of sensor supports 3 which are arranged around the axis of the outer cylinder 1 at equal angles, and each sensor support 3 is vertically connected on the inner wall of the outer cylinder 1.
As a preferred embodiment of the test device for the influence of the mutual properties of frozen soil and concrete, at least two temperature sensors 4 are provided on each sensor holder 3, and the respective temperature sensors 4 on the sensor holder 3 are provided in the longitudinal direction of the sensor holder 3 along the diameter direction of the outer cylinder 1.
As a preferred embodiment of the testing device for the mutual property influence of the frozen soil and the concrete, as shown in fig. 2, the outer shell is detachably connected with a transparent side door 7, and the change of the frozen soil and the concrete can be directly observed through the side door 7.
As a preferred embodiment of the testing device for the mutual influence of the characteristics of the frozen soil and the concrete, the side door 7 is provided with a concrete injection pipe 10 corresponding to the concrete filling cavity.
As a preferred embodiment of the test device for the influence of the mutual properties of frozen soil and concrete, the difference in diameter between the outer and inner shells is much larger than the difference in diameter between the inner and inner shells.
As a preferred embodiment of the test device for the influence of the mutual properties of the frozen soil and the concrete, a support is connected to the outer wall of the outer housing, which is placed transversely relative to the ground when the support is supported on the ground.
An optimal embodiment of the test equipment for the mutual property influence of the frozen soil and the concrete comprises the following steps: an outer cylinder which provides experimental space, and two support legs are welded at the bottom; a large cylinder, which is used for placing soil between the large cylinder and the outer cylinder; a small cylinder, the space formed between the small cylinder and the frozen soil is used for concrete injection; the sensor bracket group is welded on the inner wall of the outer cylinder and is uniformly distributed; a temperature sensor provided on the sensor holder; the cooling pipe is spirally wound in the outer cylinder cavity and used for freezing soil body to a frozen soil state; the right door is connected with the outer cylinder through bolts and seals the cavity; the left door is connected with the outer cylinder through bolts and seals the cavity; the glass side door replaces the left side door closed cavity, and the equal strength process of the concrete and the state change of the frozen soil can be observed in real time through the glass side door.
In the equipment of the utility model, the outer diameter of the large cylinder represents the outer diameter of the whole machine of the shield machine, namely the diameter of the tunnel when the tunnel is just excavated, so that frozen soil is filled between the large cylinder and the outer cylinder, the outer diameter of the small cylinder represents the outer diameter of a pipe piece, so that concrete is injected between the small cylinder and the frozen soil, the thickness is the difference between the outer diameters of the large cylinder and the small cylinder, the state change between the concrete and the frozen soil during lining of the tunnel is simulated, and the state monitoring is carried out through a built-in temperature sensor and a glass side door.
Thus, according to the utility model, the device can simulate the equal strength process of concrete in frozen soil. As a result, the influence of the concrete with different temperatures on the frozen soil state can be tested, and the temperature of each point of the frozen soil is measured through the temperature sensor, so that the state change process of the frozen soil is monitored; by comparing the stability change of the frozen soil with the equal strength time of the concrete at different temperatures, the optimal working temperature of the concrete when lining the tunnel can be judged; due to the transparency of the glass side door, the equal strength process of the concrete in the frozen soil and the thawing and sinking phenomena of part of the frozen soil can be observed in real time.
Specifically, as shown in fig. 1, an apparatus for testing the interaction between concrete and frozen soil at different temperatures comprises an outer cylinder 1, a cooling pipe 2, a temperature sensor 4, a large cylinder 5 and a small cylinder 6. The left side and the right side of the outer cylinder 1 can be connected with the left side door 8 and the right side door 9 through bolts, so that the sealing performance of an experimental environment is ensured, as shown in the figure 2; as shown in fig. 3, the cooling pipe 2 is spirally wound between the outer cylinder 1 and the large cylinder 5, and can be filled with liquid nitrogen to freeze soil; as shown in fig. 1 and fig. 3, the sensor support 3 is uniformly distributed in the outer cylinder 1 and welded with the inner wall of the outer cylinder 1, and the sensor support 3 can enable the temperature sensor 4 to be firmly fixed in frozen soil so as to enable the temperature sensor to work stably; the temperature sensor 4 is used for measuring the temperature of each point in the frozen soil so as to reflect the state change of the frozen soil; the large cylinder 5 is connected with the right door 9 through bolts, and can form a closed space with the outer cylinder 1 for filling soil; the small cylinder 6 is connected with the right door 9 through bolts, and a closed space can be formed between the small cylinder and the frozen soil for injecting concrete. Before the concrete is to be poured, the glass side door 7 is connected to the outer cylinder 1 instead of the left side door 8, and concrete is poured through the concrete pouring nozzle 10.
A method for testing the interaction of frozen soil and concrete, comprising the testing device for the interaction of frozen soil and concrete according to any one of the above, the testing method comprising the following steps:
firstly filling a soil sample in a soil sample filling cavity, then freezing the soil sample in the soil sample filling cavity through a refrigerating unit, then disassembling an inner shell, injecting concrete into the concrete filling cavity, measuring the temperature of each point in the soil sample filling cavity through a temperature measuring unit, observing the thawing phenomenon and state change of the soil and the equal strength process of the concrete, adopting the concrete with different temperatures to carry out a repeatability experiment, recording the equal strength time of the concrete and the temperature of each point in the soil sample filling cavity at the moment, and selecting the concrete temperature suitable for practical engineering application through comparison.
As a preferred implementation mode of the testing method, firstly, an outer shell, an inner shell and an inner shell are connected with a right door 9, a testing device is placed down to the right door 9 for grounding, a soil body sample is added between the outer shell and the inner shell, after the soil body sample is filled up, the left door 8 is connected with the outer shell, then the testing device is restored to the original position, liquid nitrogen is introduced into the testing device through a cooling pipe 2, soil in a soil body sample filling cavity is frozen, after the soil body reaches a frozen soil state, the left door 8 and the inner shell are removed, a side door 7 is connected with the outer shell, then concrete with a certain temperature is injected between the inner shell and the frozen soil through a concrete injection pipe 10, after the concrete is filled up, the temperature of each point of the frozen soil is measured through a temperature sensor 4, the processes of the thawing phenomenon, the state change of the soil body, the concrete and the like are directly observed on one side of the side door 7, repeated experiments are carried out by using concrete with different temperatures, the time for the concrete and the concrete temperature of each point of the time are recorded, and the concrete temperature of each point of the time is selected to be suitable for practical engineering application.
As a preferred implementation mode of the testing method, a single variable is controlled to test, the temperature of the concrete filled in the concrete filling cavity is unchanged, accelerator with different proportions is added into the concrete, then the temperature sensor 4 and the acquisition instrument are used for collecting the temperature changes of the frozen soil at different positions in the axial direction and the radial direction, and finally the influence area and the influence time of the concrete heat release on the surrounding frozen soil are minimum under the condition that the adding proportion of the accelerator is determined.
As the optimal implementation mode of the test method, firstly, an outer cylinder 1, a large cylinder 5 and a small cylinder 6 are connected with a right door 9 through bolts, equipment is placed down to enable the right door 9 to land, soil is added between the large cylinder 5 and the outer cylinder 1, after the equipment is filled up, a left door 8 is connected with the outer cylinder 1 through bolts, then the equipment is restored to the original position, liquid nitrogen is introduced into the equipment through a cooling pipe 2 to freeze soil, after the soil reaches a frozen soil state, the left door 8 and the large cylinder 5 are removed, a glass side door 7 is connected with the outer cylinder 1 through bolts, then concrete with a certain temperature is injected between the small cylinder 6 and the frozen soil through a concrete injection pipe orifice 10, after the equipment is filled up, the temperature of each point of the frozen soil is measured through a temperature sensor 4, and the equipment stands on one side of the glass side door 7, the thawing phenomenon and the state change of the soil and the strong process of the concrete and the like can be directly observed. Repeating experiments are carried out by using concrete with different temperatures, the time for the equal strength of the concrete and the temperature of each point of the frozen soil at the moment are recorded, and the concrete temperature suitable for practical engineering application can be selected through comparison.
In the embodiment, soil mass with certain water content is filled between the outer cylinder and the large cylinder, and then freezing is carried out to simulate a frozen soil layer; and filling concrete in a gap between the large cylinder and the small cylinder, and simulating a grouting layer of the shield tail of the shield. During experiments, firstly, a large cylinder is installed, soil is filled between the outer cylinder and the large cylinder, and then liquid nitrogen is injected into a freezing pipeline to form a frozen soil layer; then taking out the large cylinder, installing the small cylinder, and filling concrete with different proportions of accelerator into the gap; and then, collecting the frozen soil temperature changes at different positions in the radial direction of the frozen soil layer through a temperature sensor and an acquisition instrument, and finally determining that the influence area of concrete heat release on surrounding frozen soil is minimum and the influence time is shortest under the condition of a certain accelerator adding proportion. The specific method is as follows:
the concrete with the A% accelerator adding proportion, when the setting time is a, measuring the temperature distribution of different distribution radiuses in the radial direction of surrounding frozen soil;
and (3) when the setting time of the concrete with the B percent accelerator is a, measuring the temperature distribution of different distribution radiuses in the radial direction of surrounding frozen soil.
In the whole experiment, the influence on surrounding frozen soil in the concrete solidification process is detected by controlling a single variable and different addition ratios of the accelerator.
The present utility model is not limited to the conventional technical means known to those skilled in the art.
The foregoing has shown and described the basic principles, main features and advantages of the present utility model. The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims (17)

1. The utility model provides a test equipment that frozen soil and concrete mutual characteristic influence which characterized in that: the device comprises an outer shell and an inner shell which are arranged in a nested manner, wherein a soil sample filling cavity is formed between the outer shell and the inner shell, a space surrounded by the inner wall of the soil sample is a concrete filling cavity, and a refrigerating unit and a temperature measuring unit are arranged in the soil sample filling cavity.
2. The test apparatus for interaction of frozen soil and concrete according to claim 1, wherein: an inner shell is nested in the inner shell, and a concrete filling cavity is arranged between the soil body sample and the inner shell.
3. The test apparatus for interaction of frozen soil and concrete according to claim 2, wherein: the inner shell is a small cylinder (6).
4. A test apparatus for the interaction of frozen soil with concrete according to any one of claims 1 to 3, wherein: the refrigerating unit comprises a cooling pipe (2) arranged in the soil body sample filling cavity, and the cooling pipe (2) is connected with the liquid nitrogen cooling system.
5. The test apparatus for interaction of frozen soil and concrete according to claim 4, wherein: the cooling pipe (2) is spirally arranged along the length direction of the inner shell.
6. The apparatus for testing the interaction of frozen soil and concrete according to any one of claims 1 to 3 and 5, wherein: the temperature measuring unit comprises a temperature sensor (4) arranged in the soil body sample filling cavity.
7. The test apparatus for interaction of frozen soil and concrete according to claim 6, wherein: the outer shell is an outer cylinder (1), the inner shell is a large cylinder (5), the outer cylinder (1) and the large cylinder (5) are coaxially arranged, and a left side door (8) and a right side door (9) are respectively arranged at two ends of the outer cylinder.
8. The apparatus for testing the interaction of frozen soil and concrete according to claim 7, wherein: the two ends of the outer cylinder (1) or/and the large cylinder (5) or/and the small cylinder (6) are respectively detachably connected with the left door (8) and the right door (9).
9. The test apparatus for interaction of frozen soil with concrete according to claim 7 or 8, characterized in that: the temperature sensor (4) is arranged on the sensor support (3), the sensor support (3) is provided with a plurality of rings along the axis of the outer cylinder (1), each ring comprises a plurality of sensor supports (3) which are arranged around the axis of the outer cylinder (1) at equal angles, and each sensor support (3) is vertically connected to the inner wall of the outer cylinder (1).
10. The apparatus for testing the interaction of frozen soil and concrete according to claim 9, wherein: at least two temperature sensors (4) are arranged on each sensor support (3), and each temperature sensor (4) on each sensor support (3) is arranged in the length direction of the sensor support (3) along the diameter direction of the outer cylinder (1).
11. The apparatus for testing the interaction of frozen soil and concrete according to any one of claims 1 to 3, 5, 7, 8, 10, wherein: the outer shell is detachably connected with a transparent side door (7).
12. The apparatus for testing the interaction of frozen soil and concrete according to claim 11, wherein: and a concrete injection pipe (10) corresponding to the concrete filling cavity is arranged on the side door (7).
13. The apparatus for testing the interaction of frozen soil and concrete according to any one of claims 1-3, 5, 7, 8, 10, 12, wherein: the difference in diameter between the outer housing and the inner housing is substantially greater than the difference in diameter between the inner housing and the inner housing.
14. The apparatus for testing the interaction of frozen soil and concrete according to claim 13, wherein: the outer wall of the outer shell is connected with a support, and when the support is supported on the ground, the outer shell is transversely placed relative to the ground.
15. A method for testing the mutual property influence of frozen soil and concrete is characterized by comprising the following steps: a test apparatus comprising the interaction of the frozen soil of any one of claims 1-14 with concrete, the test method comprising:
firstly filling a soil sample in a soil sample filling cavity, then freezing the soil sample in the soil sample filling cavity through a refrigerating unit, then disassembling an inner shell, injecting concrete into the concrete filling cavity, measuring the temperature of each point in the soil sample filling cavity through a temperature measuring unit, observing the thawing phenomenon and state change of the soil and the equal strength process of the concrete, adopting the concrete with different temperatures to carry out a repeatability experiment, recording the equal strength time of the concrete and the temperature of each point in the soil sample filling cavity at the moment, and selecting the concrete temperature suitable for practical engineering application through comparison.
16. The method for testing the interaction of frozen soil and concrete according to claim 15, wherein: firstly, an outer shell, an inner shell and an inner shell are connected with a right door (9), test equipment is placed down to the right door (9) to land, a soil body sample is added between the outer shell and the inner shell, after the soil body sample is filled up, a left door (8) is connected with the outer shell, then the test equipment is restored to the original position, liquid nitrogen is introduced into the test equipment through a cooling pipe (2), soil in a soil body sample filling cavity is frozen, after the soil body reaches a frozen state, the left door (8) and the inner shell are removed, a side door (7) is connected with the outer shell, then concrete with a certain temperature is injected between the inner shell and the frozen soil through a concrete injection pipe (10), after the concrete is filled up, the temperature of each point of the frozen soil is measured through a temperature sensor (4), the processes of thawing phenomenon, state change of the soil body, concrete and the like are directly observed on one side of the side door 7, the concrete with different temperatures is repeatedly tested, the time of the concrete and the like and the temperature of each point of the frozen soil is recorded, and the concrete is suitable for practical application of engineering is selected through comparison.
17. The method for testing the interaction of frozen soil and concrete according to claim 15 or 16, wherein: and controlling a single variable to test, wherein the temperature of the concrete injected into the concrete filling cavity is unchanged, adding accelerating agents with different proportions into the concrete, then collecting the temperature changes of the frozen soil at different positions in the axial direction and the radial direction through a temperature sensor (4) and a collecting instrument, and finally determining that the heat release of the concrete has the smallest influence area and the shortest influence time on surrounding frozen soil under the condition of determining the adding proportion of the accelerating agent.
CN202310058730.6A 2023-01-13 2023-01-13 Equipment and method for testing interaction characteristic influence of frozen soil and concrete Pending CN116429815A (en)

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CN202310058730.6A CN116429815A (en) 2023-01-13 2023-01-13 Equipment and method for testing interaction characteristic influence of frozen soil and concrete

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CN202310058730.6A CN116429815A (en) 2023-01-13 2023-01-13 Equipment and method for testing interaction characteristic influence of frozen soil and concrete

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