CN115308022A - Subway connection channel freezes analogue test system - Google Patents
Subway connection channel freezes analogue test system Download PDFInfo
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- CN115308022A CN115308022A CN202210930189.9A CN202210930189A CN115308022A CN 115308022 A CN115308022 A CN 115308022A CN 202210930189 A CN202210930189 A CN 202210930189A CN 115308022 A CN115308022 A CN 115308022A
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- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
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- G01N25/00—Investigating or analyzing materials by the use of thermal means
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Abstract
The embodiment of the invention provides a subway communication channel freezing simulation test system, which comprises: the model box body comprises a water inlet chamber, a soil filling chamber and a water outlet chamber and is used for simulating the environment of a subway communication channel; the refrigeration cycle module comprises a cold bath machine and a freezing pipe group arranged on the simulation box body and is used for providing a low-temperature environment for the simulation box body so as to simulate the low-temperature environment during freezing construction; the seepage module comprises a water tank, a heater and a circulating pipeline and is used for injecting water into the model box body so as to simulate seepage return liquid of the subway communication channel; and the monitoring module comprises a sensor group and a collector and is used for monitoring the environmental data of the simulated subway communication channel in real time.
Description
Technical Field
The invention relates to the technical field of urban rail transit construction, in particular to a subway communication channel freezing simulation test system
Background
In recent years, the construction and operation mileage of subways in China is increased explosively. For example, by the end of 2020, the total operating mileage of Beijing subway has reached 727km. According to the planning, the Beijing subway operating line will exceed 1000km by 2050. In Beijing area, the previous municipal rail underground excavation engineering mostly focuses on precipitation construction, the daily precipitation can reach 25-60 thousands of cubes, and the annual precipitation can reach hundreds of millions of cubes, so that the great waste of underground water resources is caused, and the project construction is prohibited from pumping underground water since 2017. As a typical method for construction without precipitation, the artificial freezing method is widely popularized in the field of underground engineering such as mines, tunnels, foundation pits and the like. The manual freezing method is characterized in that when various underground projects are tunneled under complex hydrogeological conditions, temporary freezing walls are built around the temporary freezing walls to isolate the connection of underwater inside and outside the freezing walls and resist water and soil pressure, so that the stability of water-containing soil in tunneling construction is ensured, and the aim of reinforcing the stratum is to be achieved urgently by temporarily changing the rock-soil property by utilizing the manual refrigeration technology.
The strength of the artificial frozen soil is an important theoretical basis for evaluating the stability of the frozen wall, and is obviously influenced by the temperature and the thickness of the frozen wall. Compared with soft soil in Tianjin area and clay in east China, sandy silt and red soil in south China, beijing is located at the junction of Taihang mountain, yanshan mountain and North China plain and mainly located on the flung fan of the Yongding river, and the occurrence state of underground water is complex. The sand-gravel stratum is widely distributed along the subway, the seepage property is extremely strong, the freezing temperature field is obviously influenced by the seepage effect of underground water, and the freezing temperature field has certain particularity in the freezing process, so that other research results of urban freezing construction cannot be directly used for reference. The groundwater seepage is a core factor influencing a freezing temperature field, the flow of groundwater in a stratum can continuously supplement heat of a freezing area, so that the distribution and development rules of the freezing temperature field are greatly different from those of a still water condition, the average temperature and thickness of a freezing wall are not as expected, and the safety promotion of a freezing project is seriously restricted.
In the process of reinforcing the stratum by the artificial freezing method, the temperature of the stratum is continuously reduced along with the continuous heat exchange, and when the temperature reaches the freezing point, the volume of a soil body is obviously increased under the influence of segregation freezing caused by in-situ freezing of pore water and water migration of an unfrozen area, so that the uneven deformation of the ground surface is caused; after freezing construction is finished, the frozen soil body is gradually ablated along with the rise of the temperature of the stratum, and obvious melting and sinking phenomena occur in the stratum by overlapping the soil particle compaction and rearrangement processes under the action of an overlying load. Considering the complicated environment around the urban subway communication channel, if the frost heaving and thaw settlement can not be effectively controlled, the adverse effect is brought to the foundation of the superstructure or the building and the adjacent municipal pipe network facilities, and huge economic loss and social influence are caused.
In view of this, the formation rule of the sand-gravel stratum communication channel freezing wall and the surrounding environmental effect under the seepage condition need to be studied deeply. The current research methods for the problems mainly comprise numerical simulation, field test and model test. Model simplification, parameter selection and boundary conditions of numerical simulation have important influence on a calculation result, and the guidance of the calculation result on an actual project is questionable considering the complexity of a communication channel freezing project; the reliability of the field test is high, the field actual situation can be reflected, but the expenditure and the energy consumption in the test process are extremely high, and the possibility of repeated tests is not provided; the model test cost is controllable, and the reliability is high, so that the method is an important means for researching complex engineering problems. However, the stratum freezing under the condition of still water or low-speed seepage is mainly considered in the model test research related to the existing freezing method, most of simulated objects are clay, sandy soil and other fine-particle soil, the artificial freezing of the clay and sandy soil combined stratum is simulated, the sandy gravel stratum has extremely strong seepage performance, a freezing temperature field and a deformation field are obviously influenced by seepage, and the model test research related to the freezing method has certain particularity in the freezing process, and the research result of fine-particle soil freezing cannot be directly used for reference. In addition, most of freezing pipes of model tests adopt a single-pipe, single-pipe or multi-pipe arrangement mode, such pipe arrangement modes mainly simulate practical engineering of subway station floor or foundation pit freezing, and a communication channel is of a straight-wall vault structure, the arrangement scheme of the freezing pipes is greatly different from the pipe arrangement scheme, and the test result of the test scheme does not have an exact conclusion about whether the development rules of a freezing temperature field and a deformation field of the communication channel can be reflected.
Disclosure of Invention
The embodiment of the invention provides a subway communication channel freezing simulation test system, which overcomes the defects of the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme.
In one aspect, the invention provides a subway communication channel freezing simulation test system, which comprises:
the model box body comprises a water inlet chamber, a soil filling chamber and a water outlet chamber and is used for simulating the environment of a subway communication channel;
the refrigeration cycle module comprises a cold bath machine and a freezing pipe group arranged on the simulation box body and is used for providing a low-temperature environment for the simulation box body so as to simulate the low-temperature environment during freezing construction;
the seepage module comprises a water tank, a heater and a circulating pipeline and is used for injecting water into the model box body so as to simulate seepage return liquid of the subway communication channel; and
and the monitoring module comprises a sensor group and a collector and is used for monitoring the environmental data of the simulated subway contact channel in real time.
Optionally, a seepage liquid inlet pipe communicated with the water inlet chamber is arranged on one side wall of the model box body, and a seepage liquid outlet pipe communicated with the water outlet chamber is arranged on the other side wall of the model box body.
Optionally, the freezing pipe group comprises a plurality of freezing pipes arranged in the simulation box body, and a liquid inlet main pipe and a liquid outlet main pipe which are respectively arranged at two ends of the freezing pipes and are used for forming a refrigerating fluid circulation loop; the refrigerating module also comprises an anti-freezing pipe which is used for being respectively connected with the cold bath machine, the liquid inlet main pipe, the cold bath machine and the liquid outlet main pipe and is used for forming an anti-freezing liquid circulation loop.
Optionally, the percolation module further comprises: the power pump is arranged on the circulating pipeline; the pressure gauge is arranged on the circulating pipeline and used for monitoring pressure; and the flowmeter is arranged on the circulating pipeline and used for monitoring the flow.
Optionally, the sensors include temperature sensors, stress sensors, and deformation sensors, and the collector includes a Campbell CR6 series and a plurality of channel expansion plates.
Optionally, the method for designing the system includes the following steps:
obtaining a similarity criterion of model test influence factors through dimensional analysis;
determining similarity ratios of the subway communication channel freezing simulation test system according to the environment of the subway communication channel, wherein the similarity ratios comprise a geometric similarity ratio, a material similarity ratio, a time similarity ratio, a brine flow similarity ratio, a groundwater flow speed similarity ratio and a load similarity ratio;
designing a model box body according to first preset data, wherein the first preset data comprise geometric similarity ratio, material strength and rigidity conditions and control initial water head difference;
designing a refrigeration cycle module according to second preset data, wherein the second preset data comprises a brine flow similarity ratio, a preset communication channel pipe arrangement structure and a preset energy consumption requirement;
designing a seepage module according to third preset data, wherein the third preset data comprises a groundwater flow speed similarity ratio, a water temperature similarity ratio and a preset test flow speed;
and designing a monitoring module according to a preset test rule, a to-be-tested object and a test precision requirement of the subway communication channel freezing simulation test system.
Optionally, the model test influencing factors include a temperature field, a seepage field and a stress field.
Optionally, the design method of the simulation box further includes:
a water inlet chamber and a water outlet chamber are respectively arranged on two sides of the simulation box body and are used for reducing the direct scouring effect of underground water on a test soil body;
two layers of 250-mesh steel wire filter screens are arranged on the inner sides of the water inlet chamber and the water outlet chamber and are used for preventing fine granular soil from losing and entering a pipeline of a system;
the water outlet chamber is divided into four independent cavities which are respectively connected with the seepage liquid outlet pipe and used for reducing different initial flow rates of each stratum caused by water head difference of the water storage chamber;
when filling soil, four layers of customized copper partition plates are arranged for reducing the infiltration of underground water under the action of gravity as much as possible, and waterproof glue is adopted between the partition plates and the freezing pipes for stopping water.
Optionally, the method for designing a refrigeration cycle module further includes:
selecting a cold bath machine with specified power according to the energy consumption requirement;
designing a freezing pipe group according to a reasonable similarity ratio by using a pipe distribution scheme of an actual freezing project, and selecting the same material as that of a field freezing pipe to prepare the freezing pipe group;
electromagnetic valves are arranged on two sides of each freezing pipe to control the opening and closing of each freezing pipe.
Optionally, the design method of the seepage module further comprises:
simulating the flow speed of 20m/d underground water by a power pump;
each layer of cavity is connected with 3 water inlet pipes and 3 water outlet pipes which are connected in parallel by adopting main pipes and then connected with a seepage circulation pipeline;
the water in the water tank is always in a constant temperature state through a heater and a temperature control device arranged in the water tank and used for automatically heating;
the flow rate is controlled by pressure and flow.
The invention has the beneficial effects that: the real-time monitoring of the temperature field, the stress field and the deformation field in the artificial freezing process of the subway communication channel in the sandy gravel stratum under the seepage condition is realized, the development and evolution rules of all physical quantities are analyzed, and a basis is provided for the design and construction of the subway communication channel freezing project. The simulation test system realizes the simulation of the high-speed seepage of the sandy gravel stratum and solves the problem that the existing model test only considers the condition that fine-grained soil such as clay, sandy soil and the like is in still water or low-speed seepage; by arranging the multilayer water storage chambers and the seepage channels, the problem that the test result is influenced by large difference of seepage speeds of the upper layer and the lower layer of the soil body in the existing model test is solved; meanwhile, the freezing pipes of the simulation test are designed according to the pipe distribution characteristics of the freezing pipes of the on-site communication channels, and the electromagnetic valves are configured, so that the flexible simulation of different communication channel freezing pipe arrangement schemes is realized. The simulation test system has important significance for design and construction of subway communication channel freezing projects of water-rich sandy gravel strata.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a subway communication channel freezing simulation test system according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a mold box according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a refrigeration cycle module provided by an embodiment of the present invention; and
fig. 4 is a schematic diagram of a seepage circulation module according to an embodiment of the present invention.
Reference numerals are as follows: 1. a model box body; 2. a cold bath machine; 3. a water tank; 4. a flow meter; 5. a pressure gauge; 6. a power pump; 7. a seepage control gate valve; 8. a seepage outlet pipe; 9. a seepage liquid inlet pipe; 10. a water outlet chamber; 11. a water inlet chamber; 12. a copper separator; 13. punching a hole plate by stainless steel; 14. a stainless steel filter screen; 15. a steel separator plate; 16. a refrigerating fluid outlet pipe; 17. a chilled liquid gate valve; 18. a refrigerating fluid inlet pipe; 19. a liquid inlet main pipe; 20. a liquid outlet main pipe; 21. a freezing pipe; 22. an electromagnetic valve; 23. a seepage liquid inlet pipe; 24. a constant temperature heater; 25. and (4) seepage and outflow pipes.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
As used herein, the singular forms "a", "an", "the" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
For the convenience of understanding of the embodiments of the present invention, the following description will be further explained by taking specific embodiments as examples with reference to the drawings, and the embodiments are not to be construed as limiting the embodiments of the present invention.
Examples
The embodiment provides a subway communication channel freezing simulation test system, which comprises:
the model box body 1 comprises a water inlet chamber 11, a soil filling chamber and a water outlet chamber 10 and can be used for simulating the environment of a subway communication channel; the refrigeration cycle module comprises a cold bath machine 2 and a freezing pipe group arranged on the simulation box body, and can be used for providing a low-temperature environment for the simulation box body so as to simulate the low-temperature environment during freezing construction; the seepage module comprises a water tank 18, a heater 24 and a circulating pipeline and is used for injecting water into the model box body so as to simulate seepage return liquid of a subway communication channel; and the monitoring module comprises a sensor group and a collector and is used for monitoring the environmental data of the simulated subway contact channel in real time.
In this embodiment, a seepage inlet pipe 9 communicated with the inlet chamber 11 is disposed on one side wall of the model box 1, and a seepage outlet pipe 8 communicated with the outlet chamber 10 is disposed on the other side wall of the model box 1.
In this embodiment, the model box 1 sequentially includes, from left to right, an inlet chamber 11, a soil filling chamber, and an outlet chamber 10, the soil filling chamber is separated from the outlet chamber 10 and the inlet chamber 11 by a stainless steel perforated plate 13, and a 250-mesh stainless steel filter screen 14 is adhered to prevent fine soil in the soil filling chamber from entering the seepage system. The water inlet chamber 11 and the water outlet chamber 10 are divided into 4 independent cavities which are respectively connected with the water inlet pipe and the water outlet pipe, and 1-2cm uniform gravels are filled in the water inlet chamber 11 and the water outlet chamber 10 in a layered mode. And sequentially filling a clay water-resisting heat-insulating layer, test sandy gravel soil and the clay water-resisting heat-insulating layer in the soil filling chamber from bottom to top, arranging 4 layers of customized copper partition plates at specified points, and burying a contact channel freezing pipe group and a sensor group at a corresponding position of a test soil body.
In this embodiment, the freezing pipe group includes a plurality of freezing pipes 21 disposed in the simulation box 1, and a liquid inlet main pipe 19 and a liquid outlet main pipe 20 respectively disposed at two ends of the freezing pipes 21, and is configured to form a refrigerating fluid circulation loop. The refrigerating module further comprises a refrigerating fluid outlet pipe 16 and a freezing fluid inlet pipe 18 which are respectively connected with the cold bath machine 2, the liquid inlet dry pipe 19, the cold bath machine 2 and the liquid outlet dry pipe 20 and are used for forming an anti-freezing fluid circulation loop.
In the embodiment, the air-cooled high-power water chiller of 7.5kw is adopted as the cold bath machine, the antifreeze solution is Shell glycol antifreeze solution, the freezing point is-45 ℃, the electromagnetic valves 22 are arranged at the two ends of the freezing pipe 21 of the communication channel to control the circulation of the brine in the freezing pipe 21, and the cold bath machine 2 and the freezing pipe 21 are sequentially connected to the anti-freezing pipe 18 to form a refrigeration cycle loop.
In this embodiment, the seepage module further includes: the power pump 6 is arranged on the circulating pipeline; the pressure gauge is arranged on the circulating pipeline and used for monitoring pressure; and the flowmeter is arranged on the circulating pipeline and used for monitoring the flow.
In this embodiment, the water tank 3 of the seepage module is 0.5m 3 The water tank 3 is internally provided with a high-power heater and a temperature control system; the circulating pipeline is sequentially provided with a power pump 6 with a head of 30m, a flowmeter and a pressure gauge so as to control the seepage velocity.
In this embodiment, the sensor includes a temperature sensor, a stress sensor, and a deformation sensor, and the collector includes a Campbell CR6 series and a plurality of channel expansion plates.
In this embodiment, the monitoring module is composed of a sensor and a collector. The sensors comprise various sensors of temperature, stress, deformation and the like, and are embedded in the appointed position of the test soil body, and the leads are sequentially arranged, are led out from the reserved hole of the box body and are connected to the collector. The collector is composed of a Campbell CR6 series and a plurality of channel expansion boards, and can realize real-time monitoring of multi-object data.
In this embodiment, the design method of the system includes the following steps:
step 1: and obtaining the similarity criterion of the model test influence factors through dimensional analysis.
Step 2: according to the environment of the subway communication channel, determining the similarity ratio of the subway communication channel freezing simulation test system, wherein the similarity ratio comprises a geometric similarity ratio, a material similarity ratio, a time similarity ratio, a brine flow similarity ratio, a groundwater flow speed similarity ratio and a load similarity ratio.
And step 3: and designing a model box body according to first preset data, wherein the first preset data comprise geometric similarity ratio, material strength and rigidity conditions and control initial water head difference.
Step 3.1: a water inlet chamber and a water outlet chamber are respectively arranged on two sides of the simulation box body and are used for reducing the direct scouring effect of underground water on a test soil body;
step 3.2: two layers of 250-mesh steel wire filter screens are arranged on the inner sides of the water inlet chamber and the water outlet chamber and are used for preventing fine granular soil from losing and entering a pipeline of a system;
step 3.3: the water outlet chamber is divided into four independent cavities which are respectively connected with the seepage liquid outlet pipe and used for reducing different initial flow rates of each stratum caused by water head difference of the water storage chamber;
step 3.4: when filling soil, four layers of customized copper partition plates are arranged for reducing the infiltration of underground water under the action of gravity as much as possible, and waterproof glue is adopted between the partition plates and the freezing pipes for stopping water.
And 4, step 4: the refrigeration cycle module is designed based on second predetermined data including a brine flow similarity ratio, a predetermined communication passage routing configuration, and a predetermined energy consumption requirement.
Step 4.1: selecting a cold bath machine with specified power according to the energy consumption requirement;
step 4.2: designing a freezing pipe group according to a reasonable similarity ratio by using a pipe distribution scheme of an actual freezing project, and selecting the same material as that of a field freezing pipe to prepare the freezing pipe group;
step 4.3: electromagnetic valves are arranged on two sides of each freezing pipe to control the opening and closing of each freezing pipe.
And 5: designing a seepage module according to third preset data, wherein the third preset data comprise a groundwater flow speed similarity ratio, a water temperature similarity ratio and a preset test flow speed;
step 5.1: simulating the flow velocity of 20m/d underground water by a power pump;
step 5.2: each layer of cavity is connected with 3 water inlet pipes and 3 water outlet pipes which are connected in parallel by adopting main pipes and then connected with a seepage circulation pipeline;
step 5.3: the water in the water tank is always in a constant temperature state through a heater and a temperature control device arranged in the water tank and used for automatically heating;
step 5.4: the flow rate is controlled by pressure and flow.
Step 6: and designing a monitoring module according to a preset test rule, a to-be-tested object and a test precision requirement of the subway communication channel freezing simulation test system.
In the embodiment of the invention, the test process is illustrated by taking the freezing construction simulation of the typical sand-gravel stratum communication channel in Beijing area as an example.
Step S1: determining the similarity ratio (1; and determining important parameters such as the size of a model box body (1m × 0.5m), the power of a cold bath machine (1 air-cooled water chiller with 7.5 kw), the lift (30 m) of a power pump and the like according to the similarity ratio.
Step S2: as shown in fig. 2, a model case 1 is purchased with a steel plate of 8mm thickness according to the size of the planned model case 1, and the model case 1 is assembled by welding; forming holes on the left and right side steel plates of the model box body 1, welding a seepage liquid outlet pipe 8 and a seepage liquid inlet pipe 9, and sticking 200-mesh stainless steel filter screens 14 in the left and right side steel plates; stainless steel punching plates 13 are respectively welded on two sides inside the model box to form a water inlet chamber 11 and a water outlet chamber 10, and a stainless steel filter screen 14 with 200 meshes is adhered on the side of the punching plates close to the test soil body.
And step S3: as shown in fig. 3, the refrigeration cycle module is provided with 1 7.5kw air-cooled chiller 2 and a chilled liquid gate valve 17 to control the flow rate of chilled liquid. The size and the arrangement distance of the communication channel freezing pipe model are determined according to the field freezing pipe arrangement scheme and the similarity ratio, and the communication channel freezing pipe model is formed by connecting stainless steel pipes with designed sizes by adopting joints; the freezing pipe group consists of freezing pipes 21, a liquid inlet main pipe 19 and a liquid outlet main pipe 20, electromagnetic valves 22 are arranged at two ends of each freezing pipe, any freezing pipe can be flexibly opened and closed through a matched control device, and the arrangement scheme adjustment of the freezing pipes under the condition of not disassembling a soil sample is realized. An anti-freezing pipe 18 is adopted to connect the cold bath machine and the liquid inlet and outlet main pipe to form a circulation loop of the anti-freezing liquid.
And step S4: as shown in fig. 4, the seepage circulation module customizes a stainless steel water tank 3, a hole is opened on the side surface of the tank body, and a seepage return pipe 23 is connected by a joint; a 2.5kw constant temperature heater 24 is arranged in the water tank, so that the water temperature in the water tank can be automatically monitored and controlled to be a designated temperature; the seepage flow return pipe 23 is sequentially connected with a seepage control gate valve 7, a power pump 6, a pressure gauge 5 and a flowmeter 4, so that the seepage speed is accurately controlled.
Step S5: during the test, 1-2cm diameter gravels are adopted, the water inlet chamber and the water outlet chamber are stacked in 4 layers, and a steel plate with the thickness of 5mm is adhered when each layer reaches the specified height, so that 4 independent water storage chambers are formed; then sequentially filling a lower clay layer, a sand-gravel layer and an upper clay layer; in the process of filling soil, copper partition plates are laid at designated positions to form independent seepage channels, freezing pipe groups and various sensors such as temperature sensors, soil pressure boxes and displacement sensors are buried at the designated positions, and real-time monitoring of multi-physical field data such as temperature, stress and deformation in the process of freezing the sand-gravel stratum connection channel under the seepage condition is achieved.
In summary, the embodiment of the invention realizes real-time monitoring of the temperature field, the stress field and the deformation field in the artificial freezing process of the subway communication channel in the sandy gravel stratum under the seepage condition, analyzes the development and evolution law of each physical quantity, and provides a basis for the design and construction of the subway communication channel freezing project. The simulation test system realizes the simulation of the high-speed seepage of the sandy gravel stratum and solves the problem that the existing model test only considers the condition that fine soil such as clay, sandy soil and the like is in still water or low-speed seepage; by arranging a plurality of layers of water storage chambers and seepage channels, the problem that the upper and lower seepage speed differences of the soil body in the existing model test have large influence on the test result is solved; meanwhile, the freezing pipes of the simulation test are designed according to the pipe distribution characteristics of the freezing pipes of the on-site communication channels, and the electromagnetic valves are configured, so that the flexible simulation of different communication channel freezing pipe arrangement schemes is realized. The simulation test system has important significance for design and construction of subway communication channel freezing projects of water-rich sandy gravel strata.
Those of ordinary skill in the art will understand that: the figures are schematic representations of one embodiment, and the blocks or processes shown in the figures are not necessarily required to practice the present invention.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the method or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described embodiments of the method and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement without inventive effort.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A subway communication channel freezing simulation test system is characterized by comprising:
the model box body comprises a water inlet chamber, a soil filling chamber and a water outlet chamber and is used for simulating the environment of the subway communication channel;
the refrigeration cycle module comprises a cold bath machine and a freezing pipe group arranged on the simulation box body and is used for providing a low-temperature environment for the simulation box body so as to simulate the low-temperature environment during freezing construction;
the seepage module comprises a water tank, a heater and a circulating pipeline and is used for injecting water into the model box body so as to simulate seepage return liquid of the subway communication channel; and
and the monitoring module comprises a sensor group and a collector and is used for monitoring the simulated environment data of the subway contact channel in real time.
2. The system of claim 1, wherein a seepage inlet pipe is arranged on one side wall of the model box body and communicated with the inlet chamber, and a seepage outlet pipe is arranged on the other side wall of the model box body and communicated with the outlet chamber.
3. The system of claim 2, wherein the freezing pipe group comprises a plurality of freezing pipes arranged in the simulation box body, and a liquid inlet main pipe and a liquid outlet main pipe which are respectively arranged at two ends of the freezing pipes and are used for forming a refrigerating fluid circulation loop;
the refrigeration module further comprises an anti-freezing pipe which is used for being connected with the cold bath machine and the liquid inlet dry pipe respectively, the cold bath machine and the liquid outlet dry pipe respectively and used for forming an anti-freezing liquid circulation loop.
4. The system of claim 3, wherein the percolation module further comprises:
the power pump is arranged on the circulating pipeline;
the pressure gauge is arranged on the circulating pipeline and used for monitoring pressure; and
and the flowmeter is arranged on the circulating pipeline and used for monitoring the flow.
5. The system of claim 1, wherein the sensors include a temperature sensor, a stress sensor, and a deformation sensor,
the collector comprises a Campbell CR6 series and a plurality of channel expansion plates.
6. A system according to claims 1-5, characterized in that the method of designing the system comprises the steps of:
obtaining a similarity criterion of the model test influence factors through dimensional analysis;
determining a similarity ratio of the subway communication channel freezing simulation test system according to the environment of the subway communication channel, wherein the similarity ratio comprises a geometric similarity ratio, a material similarity ratio, a time similarity ratio, a brine flow similarity ratio, a groundwater flow speed similarity ratio and a load similarity ratio;
designing a model box body according to first preset data, wherein the first preset data comprise the geometric similarity ratio, the material strength and rigidity conditions and a control initial water head difference;
designing a refrigeration cycle module according to second preset data, wherein the second preset data comprise the brine flow similarity ratio, a preset communication channel pipe arrangement structure and a preset energy consumption requirement;
designing the seepage module according to third preset data, wherein the third preset data comprise the groundwater flow speed similarity ratio, the water temperature similarity ratio and a preset test flow speed;
and designing a monitoring module according to a preset test rule, a to-be-tested object and a test precision requirement of the subway communication channel freezing simulation test system.
7. The system of claim 6, wherein the model test influencing factors include a temperature field, a seepage field, and a stress field.
8. The system of claim 6, wherein the method of designing the simulation enclosure further comprises:
the water inlet chamber and the water outlet chamber are respectively arranged on two sides of the simulation box body and are used for reducing the direct scouring effect of underground water on a test soil body;
two layers of 250-mesh steel wire filter screens are arranged on the inner sides of the water inlet chamber and the water outlet chamber and are used for preventing fine granular soil from losing and entering pipelines of the system;
the water outlet chamber is divided into four independent cavities which are respectively connected with the seepage liquid outlet pipe and used for reducing different initial flow rates of all stratums caused by water head difference of the water storage chamber;
when filling soil, four layers of customized copper partition plates are arranged for reducing the infiltration of underground water under the action of gravity as much as possible, and waterproof glue is adopted between the partition plates and the freezing pipes for stopping water.
9. The system of claim 6, wherein the method of designing the refrigeration cycle module further comprises:
connecting a plurality of Saimei flying high-power cold bath machines in series;
designing a freezing pipe group according to a reasonable similarity ratio by using a pipe distribution scheme of an actual freezing project, and selecting the same material as that of a field freezing pipe to manufacture the freezing pipe group;
electromagnetic valves are arranged on two sides of each freezing pipe to control the opening and closing of each freezing pipe.
10. The system of claim 6, wherein the design method of the percolation module further comprises:
simulating the flow speed of 20m/d underground water by a power pump;
each layer of cavity is connected with 3 water inlet pipes and 3 water outlet pipes which are connected in parallel by adopting main trunk pipes and then connected with a seepage circulation pipeline;
the heater and the temperature control device arranged in the water tank are used for automatically heating, so that the water in the water tank is always in a constant temperature state;
the flow rate is controlled by pressure and flow.
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| CN202210930189.9A CN115308022A (en) | 2022-08-03 | 2022-08-03 | Subway connection channel freezes analogue test system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115808437A (en) * | 2023-01-17 | 2023-03-17 | 中国建筑第二工程局有限公司 | Subway communication channel freezing method construction model test device and method |
| CN115876975A (en) * | 2022-11-23 | 2023-03-31 | 山东大学 | Liquid nitrogen cooling physical simulation test device and method for high-temperature water-rich tunnel |
| CN117554412A (en) * | 2023-11-01 | 2024-02-13 | 中国铁道科学研究院集团有限公司 | Multifunctional test device for simulating freezing process of tunnel drainage system in cold region |
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2022
- 2022-08-03 CN CN202210930189.9A patent/CN115308022A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115876975A (en) * | 2022-11-23 | 2023-03-31 | 山东大学 | Liquid nitrogen cooling physical simulation test device and method for high-temperature water-rich tunnel |
| CN115808437A (en) * | 2023-01-17 | 2023-03-17 | 中国建筑第二工程局有限公司 | Subway communication channel freezing method construction model test device and method |
| CN117554412A (en) * | 2023-11-01 | 2024-02-13 | 中国铁道科学研究院集团有限公司 | Multifunctional test device for simulating freezing process of tunnel drainage system in cold region |
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