CN111638136A - High-speed rail foundation dynamic loading model test device and method for underlying underground engineering - Google Patents
High-speed rail foundation dynamic loading model test device and method for underlying underground engineering Download PDFInfo
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- CN111638136A CN111638136A CN202010608588.4A CN202010608588A CN111638136A CN 111638136 A CN111638136 A CN 111638136A CN 202010608588 A CN202010608588 A CN 202010608588A CN 111638136 A CN111638136 A CN 111638136A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- 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
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/24—Earth materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/001—Impulsive
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/003—Generation of the force
- G01N2203/0042—Pneumatic or hydraulic means
- G01N2203/0048—Hydraulic means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
Abstract
The invention relates to a high-speed railway foundation dynamic loading model test device and a method for underlying underground engineering.A space enclosed by a bottom plate, a left side beam, a right side beam and soil body limiting plates at two sides forms a filling space of similar rock-soil bodies, a top beam is provided with a sliding table which is driven by an electric push rod and slides left and right along the length direction of the top beam, and a loading mechanism which extends downwards from the lower surface of the top beam and is positioned right above the filling space is fixed on the sliding table; when the electric push rod drives the sliding table to drive the loading mechanism to slide back and forth along the length direction of the top beam, the first steering touch plate is in contact with the steering button on the second steering touch plate and presses the steering button, the steering button is triggered, and the electric push rod changes the stretching direction.
Description
Technical Field
The invention relates to the technical field of foundation dynamic loading similar model tests, in particular to a high-speed rail foundation dynamic loading model test device and method for underlying underground engineering.
Background
The available land resources are increasingly reduced, and the laying of high-speed railway lines also meets various technical problems, wherein the foundation of the existing underground engineering is not always passed through. Therefore, a great deal of research results are urgently needed to support the actual engineering. However, for the research on the problems related to the construction of high-speed railways on the foundation of the existing underlying engineering, a large number of model tests are required in addition to the field test, and then comprehensive and reliable test data are obtained to support the actual engineering.
The invention discloses an invention patent with the publication number of CN 101787716A, a model test device for researching dynamic response and long-term settlement rule of a high-speed railway, an invention patent with the publication number of CN 106501079A and a roadbed dynamic loading model test system. The utility model discloses a utility model patent of publication No. CN 204405654U, a device of simulation collecting space area exploitation, the device is through inserting the rubber tube that is full of sand with the hollow tube in, and then reaches the purpose that simulates collecting space area exploitation with letting out sand. The device is full of husky and level is laid in the hose, and husky under the action of the dead weight of the upper soil layer, the compaction of compression and mobility are poor, and the operation is difficult, and the result is not good in test effect. The device can only simulate a shallow goaf, but cannot simulate the effect influence of high-speed rail circulating dynamic load on a goaf foundation. The invention discloses an invention patent with the publication number of CN 110409518A, and relates to a high-speed railway goaf foundation simulated power loading model test device and a method. The device water bag is placed horizontally, the water bag is soft and is easy to deform, the construction difficulty of the soil layer on the upper portion of the water bag is large, and the fixed loading device cannot accurately simulate the real running condition of a train. In addition, the invention prefabricates the rock-soil mass outside the model and then moves the rock-soil mass into the model, and the operation is extremely difficult and difficult to realize.
Disclosure of Invention
In view of the above situation, in order to overcome the defects of the prior art, the present invention aims to provide a high-speed rail foundation dynamic loading model test device and method for underlying underground engineering, which can effectively solve the problem of dynamic loading simulation test of the high-speed rail foundation of the underlying underground engineering.
The technical scheme of the invention is as follows:
a high-speed railway foundation dynamic loading model test device for underlying underground engineering comprises a base, a left side beam and a right side beam which are vertically arranged on two sides of the base, and a top beam which is horizontally arranged at the tops of the left side beam and the right side beam, wherein a plurality of soil body limiting plates which are arranged side by side are connected between two side faces of the left side beam and the right side beam; the loading mechanism comprises a supporting plate connected to the bottom of the sliding table, two symmetrical groups of telescopic loading mechanisms are respectively arranged at two ends of the supporting plate, the lower end of each telescopic loading mechanism is connected with a track wheel which stretches along the lower end of the telescopic loading mechanism, the lower surfaces of two ends of the supporting plate are connected with first steering contact plates which extend downwards, steering buttons used for changing the stretching direction of the electric push rod are respectively arranged on the first steering contact plates at two ends, the steering buttons are respectively positioned on the surfaces, far away from each other, of the first steering contact plates at two ends, relative to the central line of the supporting plate, the steering buttons are positioned on the outer sides of the telescopic loading mechanisms, the brake steering mechanisms which are positioned at the same height as the first steering contact plates are respectively arranged on the sides, close to each other, of the upper ends of the left side beam and the right side beam, second steering contact plates corresponding to the steering buttons are respectively, the first steering touch panel is in contact with the steering button on the second steering touch panel and extrudes the steering button, the steering button is triggered, and the electric push rod changes the stretching direction to form a reciprocating circulating sliding structure of the loading mechanism.
Preferably, the testing device further comprises a controller, a pressure sensor for detecting the loading force of the telescopic loading mechanism is arranged on the telescopic loading mechanism, and the controller is connected with a driving part, the pressure sensor, the electric push rod and the steering button of the telescopic loading mechanism respectively.
The telescopic loading mechanism comprises a hydraulic jack which is fixed on the bottom surface of the supporting plate and stretches along the vertical direction, a vibration exciter supporting plate which stretches and descends along with the hydraulic jack is fixed on a movable part at the lower end of the hydraulic jack, a vibration exciter which stretches and retracts along the vertical direction is fixed on the lower surface of the vibration exciter supporting plate, and the lower end of the vibration exciter is connected with a track pulley matched with the track mechanism.
The tunnel precast block or the gob precast block or the combination of the tunnel precast block and the gob precast block are embedded in the similar rock-soil body, and a sensor for monitoring dynamic stress, vibration acceleration or soil body settlement in the similar rock-soil body under dynamic load is also embedded in the similar rock-soil body.
A dynamic loading simulation test method for building underground engineering under an existing high-speed railway based on the test device comprises the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode and burying corresponding sensors 22;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the method comprises the steps of disassembling a soil body limiting plate, excavating a supporting goaf or a subway tunnel at a corresponding position on a similar rock-soil body, enabling a loading mechanism to reciprocate along a track mechanism under the condition of applying dynamic load, simulating the operation of an actual train, and monitoring the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock body through a sensor.
A dynamic loading simulation test method for operating existing underground engineering under a high-speed railway based on the test device comprises the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle; preparing tunnel precast blocks or gob precast blocks by using corresponding similar materials, and respectively simulating and replacing a gob or a subway tunnel of the underlying existing underground engineering;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode, burying corresponding sensors 22, and meanwhile burying prefabricated tunnel prefabricated blocks or gob prefabricated blocks at corresponding positions;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the loading mechanism reciprocates along the track mechanism under the condition of applying dynamic load, simulates the actual train operation, and monitors the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock mass through a sensor.
Compared with the prior art, the invention has the following advantages:
1. the application of dynamic load to the track mechanism is completed through a telescopic loading mechanism consisting of a hydraulic jack and a vibration exciter, the telescopic compensation of the vibration exciter is controlled in real time through the dynamic control of the vibration exciter according to loading force data acquired by a pressure sensor, the load applied to a steel rail is guaranteed not to change through the pressure compensation, the stability of the track loading force is kept, the distortion caused by the reduction of the applied load due to soil body settlement is avoided, and meanwhile, the actual vibration load acting frequency of a high-speed train can be truly simulated by setting a loading curve of the load;
2. the sliding table is driven to move by the electric push rod, so that a track pulley at the lower part of the loading mechanism is driven to slide on a steel rail, when a first steering touch panel is in contact with a steering button on a second steering touch panel and presses the steering button, the steering button is triggered, the electric push rod changes the telescopic direction, so that the loading mechanism slides in a reciprocating and circulating manner, different running speeds of a train can be effectively simulated by adjusting the telescopic speed of the telescopic rod, and the reciprocating movement can simulate the real working condition of the high-speed train in the reciprocating and circulating manner;
3. the filling space of the similar rock-soil body is constructed by the soil body limiting plates on the surfaces of the left side beam and the right side beam, the size of the filling space can be adjusted at will according to the size of the model by the sliding of the left side beam, and meanwhile, the hydraulic jacks are arranged in the left side beam and the right side beam to provide horizontal lateral stress boundary conditions, so that the similar rock-soil body can be laid better;
4. after the similar rock-soil bodies are laid, the supporting and supporting goaf or subway tunnel can be excavated at the corresponding positions of the similar rock-soil bodies by detaching the soil body limiting plates, or existing underground engineering such as goafs, subway tunnels, underground pipe galleries and the like can be simulated at any position by tunnel precast blocks or goaf precast blocks in the process of laying the similar rock-soil bodies, the underground engineering is simulated by using a precast block method, the layered laying of the overlying rock-soil bodies and various embedded sensors is more convenient, the similar simulation can be better completed, and the dynamic loading of a physical test model can be more accurately monitored;
5. the dynamic loading simulation test device can be used for not only carrying out the dynamic loading simulation test of the existing underground engineering under the operation of the high-speed railway, but also carrying out the dynamic loading simulation test of the underground engineering built under the existing high-speed railway, has novel and unique structure, simple operation, convenient use and good effect, is an innovation of a dynamic loading model test device of a high-speed railway foundation under the underground engineering, and has good social and economic benefits.
Drawings
Fig. 1 is a perspective view of the present invention.
Fig. 2 is a side view of the present invention.
Fig. 3-4 are perspective views of the left side rail of the present invention at two different angles.
Fig. 5 is a perspective view of the slide table of the present invention.
Fig. 6 is a perspective view of the telescopic loading mechanism of the present invention.
Fig. 7 is a perspective view of the brake steering mechanism of the present invention.
Fig. 8 is a perspective view of the track mechanism of the present invention.
Fig. 9 is a block diagram of the circuit of the present invention.
Fig. 10 is a sectional view (cut at a similar rock-soil body) in a state in which the present invention is used.
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
As shown in fig. 1-10, the invention comprises a base 2, a left side beam 3 and a right side beam 4 which are vertically arranged at two sides of the base 2, and a top beam 5 which is horizontally arranged at the top of the left side beam and the right side beam, wherein a plurality of soil mass limiting plates 9 which are arranged side by side are connected between two side surfaces of the left side beam 3 and the right side beam 4, a filling space of similar rock and soil mass is formed by a space enclosed by a bottom plate, the left side beam, the right side beam and the soil mass limiting plates at two sides, a sliding table 14 which is driven by an electric push rod 20 and slides left and right along the length direction of the top beam is arranged on the top beam 5, and a loading mechanism 12 which extends downwards from the; the loading mechanism 12 comprises a supporting plate 123 connected to the bottom of the sliding table 14, two symmetrical two groups of telescopic loading mechanisms are respectively arranged at two ends of the supporting plate 123, the lower end of each telescopic loading mechanism is connected with a track wheel 18 which stretches along with the telescopic loading mechanism, the lower surfaces of two ends of the supporting plate 123 are connected with first steering contact plates 124 which extend downwards, steering buttons 127 for changing the stretching direction of the electric push rod 20 are respectively arranged on the first steering contact plates at two ends, the steering buttons 127 are respectively positioned on the surfaces of the first steering contact plates at two ends, relative to the central line of the supporting plate, the steering buttons are positioned on the outer sides of the telescopic loading mechanisms, the brake steering mechanisms 15 which are positioned at the same height as the first steering contact plates are respectively arranged at the sides, close to each other, of the upper ends of the left side beam 3 and the right side beam 4, and second steering contact plates 151 which, when the electric push rod 20 drives the sliding table to drive the loading mechanism to slide back and forth along the length direction of the top beam, the first steering touch panel 124 contacts with and presses the steering button on the second steering touch panel 151, the steering button is triggered, and the electric push rod 20 changes the telescopic direction to form a reciprocating circular sliding structure of the loading mechanism.
In order to ensure the using effect, the testing device further comprises a controller 21, a pressure sensor for detecting the loading force of the telescopic loading mechanism is arranged on the telescopic loading mechanism, and the controller 21 is respectively connected with a driving part of the telescopic loading mechanism, the pressure sensor, the electric push rod 20 and the steering button 127.
As shown in fig. 2, the controller 21 may be fixed on the outer side wall of the end of the right side beam 4 away from the left side beam for convenient operation, the controller 21 may be connected with an operation key, a display and a power supply matched therewith, the display is used for displaying information such as parameters and states of each component; the operation keys are used for inputting instructions to perform corresponding operation on each component, perform startup and shutdown operation and the like; the power supply supplies power to each component.
The controller is used for receiving loading force data collected by the pressure sensor, controlling a driving part of the telescopic loading mechanism to stretch in real time according to the loading force data, keeping the stability of track loading force, receiving a trigger signal after the steering button is pressed down by extrusion, and converting the stretching direction of the electric push rod, and the controller is in the prior art, such as a single chip microcomputer controller with the model STC89C 51.
The telescopic loading mechanism comprises a hydraulic jack 121 fixed on the bottom surface of the supporting plate 123 and extending and contracting along the vertical direction, a vibration exciter supporting plate 125 extending and descending along with the hydraulic jack 121 is fixed to a movable part at the lower end of the hydraulic jack 121, a vibration exciter 122 extending and contracting along the vertical direction is fixed to the lower surface of the vibration exciter supporting plate 125, and the lower end of the vibration exciter 122 is connected with a track pulley 18 matched with the track mechanism 16.
The track pulley 18 comprises a wheel shaft supporting block 184 fixedly connected to the lower end of the vibration exciter, a wheel shaft 181 rotatably mounted on the wheel shaft supporting block 184 in a penetrating manner, and wheel bodies 182 fixed to both ends of the wheel shaft.
The pressure sensor may be disposed between the axle 181 and the axle support block 184 for collecting applied pressure.
In this embodiment, the driving components of the telescopic loading mechanism are the hydraulic jack 121 and the vibration exciter 122, the controller is respectively connected with the input ends of the hydraulic jack 121 and the vibration exciter 122, an initial pressure is applied through the hydraulic jack and then dynamically controlled through the vibration exciter, the telescopic compensation of the vibration exciter is controlled in real time according to loading force data acquired by the pressure sensor, the load applied on the steel rail is guaranteed not to change through the pressure compensation, the stability of the loading force on the rail is kept, the phenomenon that the applied load is reduced and distorted due to soil body settlement is avoided, and meanwhile, the actual vibration loading frequency of the high-speed train during running can be truly simulated by setting the loading curve of the load through the vibration exciter;
the lower end of the vibration exciter 122 is fixed with a first connecting plate 126, the upper end of the wheel axle supporting block 184 is fixed with a second connecting plate 183, and the first connecting plate 126 is connected with the second connecting plate 183 through bolts.
Similar rock-soil masses 23 are laid in the filling space, the upper parts of the similar rock-soil masses 23 extend out of the filling space, and the similar rock-soil masses of the extending parts are laid with the track mechanisms 16.
The track mechanism 16 comprises a base 161 laid on the upper surface of the similar rock-soil body, a track plate 162 fixed on the upper surface of the base 161, a sleeper 163 fixedly laid on the track plate 162, and a steel rail 164 fixedly laid on the sleeper 163. Track pulley 18 is in sliding engagement with rail 164.
The similar rock-soil body 19 is embedded with a tunnel precast block 11 or a goaf precast block 10 or a combination of the two, and the similar rock-soil body is also embedded with a sensor 22 for monitoring dynamic stress, vibration acceleration or soil body settlement in the similar rock-soil body under dynamic load.
If the sensor can adopt HC-3100 series vibrating string type soil pressure cell for monitoring dynamic stress in similar rock and soil bodies under dynamic load, the HC-3100 series vibrating string type soil pressure cell is matched with a dynamic soil pressure testing instrument, the dynamic soil pressure testing instrument adopts Donghua DH5937 collecting instrument, and after being connected with the HC-3100 series vibrating string type soil pressure cell, the dynamic soil pressure testing instrument is connected with a notebook computer provided with a DHDAS dynamic signal collecting and analyzing system, the dynamic stress monitoring of the similar rock and soil bodies can be carried out;
the monitoring department of the vibration acceleration in the similar rock-soil body under the dynamic load adopts a pre-embedded LCD type acceleration sensor to monitor, the acceleration sensor converts the signal into a 4-20mA standard signal, and the signal is directly collected by a control system such as a PLC or a DCS and the like and is connected with a computer;
monitoring of the settlement amount of the soil body in the similar rock-soil body under dynamic load can be realized by matching an LVDT differential transformer type displacement sensor with an XSEW high-precision display instrument and connecting a computer.
The soil pressure cell and the acceleration sensor are uniformly arranged along the soil layer from top to bottom and used for monitoring the propagation characteristics of dynamic stress and vibration acceleration along the depth direction of the soil layer; the displacement sensor is mainly arranged on the top plate of the underground engineering and the lower part of the track system to monitor the stability of the underground engineering and ensure the operation safety of the high-speed train.
In the test process, information acquired by various sensors is transmitted to a computer through an information acquisition instrument, and the data acquisition technology of the sensors is the prior art.
The upper end face and the lower end face of the left side beam 3 are respectively provided with a first pulley 31, the upper surface of the base 2 and the lower surface of the top beam 5 are respectively provided with a first pulley track 7 corresponding to the pulleys 31, the first pulleys 31 are arranged in the first pulley tracks in a sliding mode to form a front-back sliding structure of the left side beam along the length direction of the base and the top beam, and the base 2 is provided with a second hydraulic jack 6 for driving the left side beam to slide.
The second hydraulic jack 6 is connected to the controller for controlling the initial position of the left side member.
The one end that right side roof beam 4 was kept away from to the base is fixed with the first limiting plate 1 that prevents the left side roof beam and drop, and the fixed part dress of second hydraulic jack 6 is on first limiting plate 1, and the telescopic link of second hydraulic jack 6 links together with the left side roof beam, and second hydraulic jack 6 stretches out and draws back and can drive the left side roof beam and slide around first pulley track to control its initial position, simulate not unidimensional similar ground body.
The soil body limiting plate 9 can be made of channel steel, two ends of the channel steel are respectively fixed on the side beams on the corresponding sides through connecting bolts 8, and the edges of the two vertically adjacent channel steel are tightly attached to prevent soil leakage. And customizing different channel steels as soil body limiting plates according to different lengths of the left side beam 3 and the right side beam 4.
The brake steering mechanism 15 is provided with a bolt connecting hole 152, the brake steering mechanism is fixedly connected with the left side beam 3 and the right side beam 4 through a connecting bolt in the bolt connecting hole, and the upper surface of the steering mechanism 15 is separated from the top beam, so that friction in the sliding process is avoided.
The side surfaces of the left side beam 3 and the right side beam 4 close to each other are provided with force transmission pressure plates 131 driven by a third hydraulic jack 13 and used for applying lateral stress.
The third hydraulic jacks 13 are horizontally fixed in the left side beam 3 and the right side beam 4, telescopic rods of the third hydraulic jacks are connected with the force transmission pressing plate 131, and when the telescopic rods stretch, the force transmission pressing plates can be driven to extrude similar rock-soil bodies in the filling space, so that lateral stress is applied to the similar rock-soil bodies, and boundary conditions are determined.
The slide table 14 includes a bottom plate 144, the vertical plate 145 is vertically connected to the upper surface of the bottom plate, the top plate 142 is horizontally connected to the upper end of the vertical plate, the top beam 5 is provided with a second pulley rail 17 arranged along the length direction of the top beam, the top plate 142 is rotatably connected with a plurality of second pulleys 143 matched with the second pulley rails 17, the second pulleys are slidably arranged on the second pulley rails to form a guide structure of the sliding table sliding along the length direction of the top beam, the top plate 142 is fixed with a driving connecting block 141, the electric push rod 20 is fixed on one side of the top beam, an expansion link of the electric push rod 20 is fixedly connected with the driving connecting block 141, the bottom plate 144 is provided with a first bolt hole 144a, the support plate 123 is provided with a second bolt hole 123a corresponding to the first bolt hole 144a, and the bottom plate 144 and the support plate 123 are fixedly connected together through bolts and nuts which are rotatably installed in.
One end of the second pulley rail 17 away from the right side beam 4 is fixed with a second limiting plate 18 for preventing the sliding table from falling off.
The electric push rod 20 stretches and retracts to drive the sliding table to slide back and forth along the second pulley track, so as to drive the loading mechanism to slide back and forth along the steel rail.
A dynamic loading simulation test method for building underground engineering under an existing high-speed railway based on the test device comprises the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode and burying corresponding sensors 22;
after detecting that the relevant physical indexes of each layer of soil sample are qualified, manufacturing and laying the upper layer of soil;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the method comprises the steps of disassembling a soil body limiting plate, excavating a supporting goaf or a subway tunnel at a corresponding position on a similar rock-soil body, enabling a loading mechanism 12 to reciprocate along a track mechanism under the condition of applying dynamic load, simulating actual train operation, and monitoring the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock body through a sensor.
The data measured by the measuring equipment are transmitted to a computer for subsequent data processing and analysis to obtain a test result, and the simulation test for building the underground engineering below the existing high-speed railway emphasizes and monitors the influence of the excavation of the underground engineering on the rail settlement deformation.
A dynamic loading simulation test method for operating existing underground engineering under a high-speed railway based on the test device comprises the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle; preparing a tunnel precast block 11 or a goaf precast block 10 (a box body or a pipe body) by using corresponding similar materials, and respectively simulating and replacing a goaf or a subway tunnel of the existing underground engineering;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode, burying corresponding sensors 22, and burying prefabricated tunnel prefabricated blocks 11 or gob prefabricated blocks 10 at corresponding positions;
after detecting that the relevant physical indexes of each layer of soil sample are qualified, manufacturing and laying the upper layer of soil;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the loading mechanism 12 reciprocates along the track mechanism under the condition of applying dynamic load, simulates the actual train operation, and monitors the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock mass through a sensor.
The dynamic loading simulation test for the existing underground engineering under the operation of the high-speed railway emphasizes the influence of the operation of the train on the existing underground engineering, namely the monitoring on the dynamic stress and the vibration acceleration of similar rock and soil masses.
Compared with the prior art, the invention has the following advantages:
1. the application of dynamic load to the track mechanism is completed through a telescopic loading mechanism consisting of a hydraulic jack and a vibration exciter, the telescopic compensation of the vibration exciter is controlled in real time through the dynamic control of the vibration exciter according to loading force data acquired by a pressure sensor, the load applied to a steel rail is guaranteed not to change through the pressure compensation, the stability of the track loading force is kept, the distortion caused by the reduction of the applied load due to soil body settlement is avoided, and meanwhile, the actual vibration load acting frequency can be truly simulated by setting a loading curve of the load through the vibration exciter when a high-speed train runs;
2. the sliding table is driven to move by the electric push rod, so that a track pulley at the lower part of the loading mechanism is driven to slide on a steel rail, when a first steering touch panel is in contact with a steering button on a second steering touch panel and presses the steering button, the steering button is triggered, the electric push rod changes the telescopic direction, so that the loading mechanism slides in a reciprocating and circulating manner, different running speeds of a train can be effectively simulated by adjusting the telescopic speed of the telescopic rod, and the reciprocating movement can simulate the real working condition of the high-speed train in the reciprocating and circulating manner;
3. the filling space of the similar rock-soil body is constructed by the soil body limiting plates on the surfaces of the left side beam and the right side beam, the size of the filling space can be adjusted at will according to the size of the model by the sliding of the left side beam, and meanwhile, the hydraulic jacks are arranged in the left side beam and the right side beam to provide horizontal lateral stress boundary conditions, so that the similar rock-soil body can be laid better;
4. after the similar rock-soil bodies are laid, the supporting and supporting goaf or subway tunnel can be excavated at the corresponding positions of the similar rock-soil bodies by detaching the soil body limiting plates, or existing underground engineering such as goafs, subway tunnels, underground pipe galleries and the like can be simulated at any position by tunnel precast blocks or goaf precast blocks in the process of laying the similar rock-soil bodies, the underground engineering is simulated by using a precast block method, the layered laying of the overlying rock-soil bodies and various embedded sensors is more convenient, the similar simulation can be better completed, and the dynamic loading of a physical test model can be more accurately monitored;
5. the dynamic loading simulation test device can be used for not only carrying out the dynamic loading simulation test of the existing underground engineering under the operation of the high-speed railway, but also carrying out the dynamic loading simulation test of the underground engineering built under the existing high-speed railway, has novel and unique structure, simple operation, convenient use and good effect, is an innovation of a dynamic loading model test device of a high-speed railway foundation under the underground engineering, and has good social and economic benefits.
The simulation experiment data of the invention are as follows:
field test
Taking a tunnel with the burial depth of 32 meters as an example, various sensors are buried from the top plate of the tunnel to the ground surface, and the types of the sensors are as follows: displacement sensor, acceleration sensor and dynamic stress sensor. The stress and vibration related information of train operation acquired by various sensors is collected and transmitted to a computer in the operation process of the high-speed rail.
Physical and mechanical parameters of soil layer
Principle of similarity
(1) Geometric similarity ratio
The geometric similarity ratio is αL1/100, the engineering prototype length is 100m, and the goaf burial depth is 32m, so
The model dimensions were 100cm long, 40cm wide and 45cm high.
(2) Density similarity ratio
Average density of prototype formationIs rhoy2.2, dry density of model material ρm＝1.6。
αρ＝ρy/ρm＝1.6/2.2＝0.73
(3) Stress to strength similarity ratio
ασ＝αρ×αL＝0.0073
(4) Speed similarity ratio
VyVelocity, V, of a point of the prototypemVelocity of corresponding point of model
αv＝Vy/Vm
(5) Time similarity ratio
The geometric similarity ratio is αL1/100, the time similarity ratio is αt＝1/10
(6) Acceleration similarity ratio
αa＝αL/αt 2＝1
And according to the occurrence condition of the overlying rock-soil layer of the tunnel, calculating the thickness and weight of each layer of material of the model according to the geometric similarity ratio and the stress-strength similarity ratio. In the simulation test, fine river sand with the particle size of less than 0.05mm is selected as aggregate, gypsum and calcium carbonate have the characteristic of brittle failure, the gypsum is selected as a main cementing material, the calcium carbonate is selected as an auxiliary cementing material, and mica powder is used for simulating weak surfaces between rock stratums. Because the gypsum material has higher solidification and cementation speed, a small amount of borax is added into similar materials to be used as a retarder, and water is added to prepare a solution with the concentration of 1 percent. The similar mixture ratio of the materials is as follows:
material similarity proportioning table
| Serial number | Lithology | Thickness/cm | Layering | Match number | Sand/kg | Lime/kg | Gypsum per kg | Water/kg |
| 1 | |
3 | 2 | 537 | 42 | 2.6 | 5.9 | 5 |
| 2 | Build-up and flood- |
8 | 2 | 437 | 107.5 | 8.2 | 18.9 | 13.4 |
| 3 | Plastic |
10 | 2 | 355 | 122.5 | 7.4 | 17.1 | 14.8 |
| 4 | Completely weathered |
9 | 3 | 337 | 113.3 | 11.4 | 26.3 | 15.2 |
| 5 | Strongly weathered |
5 | 1 | 573 | 78.3 | 10.9 | 4.7 | 9.4 |
| 6 | Moderately weathered |
5 | 1 | 328 | 52.3 | 8.6 | 4.6 | 8.2 |
Mixing the raw materials in a ratio of 1: and 100, performing a physical model test on the similarity ratio, preparing similar rock-soil bodies and tunnel prefabricated blocks according to the similarity ratio of the parameters, and determining the thickness, the moving speed, the loading load and the like of each soil layer. The sensor types are as follows: displacement sensor, acceleration sensor and dynamic stress sensor. The distance and the buried depth of various sensors are also determined according to the geometric similarity ratio of 1: 100, and burying. The form of the vehicle load may take the form of a sinusoidal waveform pulse:
P(t)＝P0+Psin(2πft)
wherein: p is the pressure on the contact patch; p0The vehicle static load is adopted, and P is a vibration load amplitude; f is the load action frequency, and the frequency is the actual load action frequency. Applying train static load P by using hydraulic jack on loading mechanism0And adjusting the loading frequency f and the vibration load amplitude P of the vibration exciter. After the equipment is debugged, the simulation test can be carried out through the model test device.
The following experimental data are measured for 50 times of train reciprocating operation:
data collected by the model test device:
dynamic stress:
| depth of burial (cm) | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 |
| Dynamic stress (Kpa) | 0.65 | 0.45 | 0.3 | 0.2 | 0.12 | 0.07 | 0.04 | 0.02 | 0.01 |
Vertical vibration acceleration:
| depth of burial (cm) | 0 | 1 | 5 | 10 | 15 | 20 |
| Vertical acceleration (m/s) | 0.038 | 0.036 | 0.022 | 0.01 | 0.0037 | 0.001 |
And (3) settling:
| depth of burial (cm) | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 |
| Sedimentation (mm) | 1.5 | 2.2 | 3.0 | 4.12 | 5.16 | 6.04 | 6.75 | 7.62 | 8.31 |
Actual measurement data of a field test:
dynamic stress:
| buried depth (m) | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 |
| Dynamic stress (Kpa) | 53 | 42 | 24 | 18 | 10 | 6 | 3 | 1.6 | 0.8 |
Vertical vibration acceleration:
| buried depth (m) | 0 | 1 | 5 | 10 | 15 | 20 |
| Vertical acceleration (m/s) | 0.04 | 0.035 | 0.020 | 0.008 | 0.0037 | 0.001 |
And (3) settling:
| buried depth (m) | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 |
| Sedimentation (cm) | 13 | 19 | 28 | 41.2 | 50.6 | 61 | 68 | 75 | 81 |
From the above situation, it is clear that the dynamic stress and the vibration acceleration process the monitoring data according to the similarity ratio principle, and the monitoring data obtained by the method is very close to the numerical analysis and field monitoring results, and the dynamic stress and the vertical vibration acceleration both meet the exponential type attenuation characteristics in the depth direction under the three monitoring methods. According to the design standard of power machine foundation, the transmission rule of dynamic stress and vertical vibration acceleration under vibration load along the depth direction of the rock-soil body is exponentially attenuated. Therefore, the test result of the device has high accuracy. In addition, the test results meet the requirements for stability of underground engineering and operation safety evaluation of high-speed trains. Therefore, the invention has high practical application value.
Claims (10)
1. A high-speed railway foundation dynamic loading model test device of underlying underground engineering is characterized by comprising a base (2), a left side beam (3) and a right side beam (4) which are vertically arranged on two sides of the base (2), and a top beam (5) horizontally arranged at the tops of the left side beam and the right side beam, wherein a plurality of soil body limiting plates (9) which are arranged side by side are connected between two side surfaces of the left side beam (3) and the right side beam (4), a filling space of similar rock bodies is formed by a space enclosed among a bottom plate, the left side beam, the right side beam and the soil body limiting plates on two sides, a sliding table (14) which is driven by an electric push rod (20) and slides left and right along the length direction of the top beam is arranged on the top beam (5), and a loading mechanism (12) which extends out of the lower surface of the top beam downwards and is positioned right; loading mechanism (12) are including connecting backup pad (123) in slip table (14) bottom, backup pad (123) both ends are provided with two sets of flexible loading mechanism of symmetry respectively, flexible loading mechanism lower extreme is connected with rail wheel (18) flexible along with it, backup pad (123) both ends lower surface is connected with downwardly extending's first direction touch panel (124), be provided with turn button (127) that are used for changing electric putter (20) flexible direction on the first direction touch panel at both ends respectively, turn button (127) are located the first direction touch panel in both ends and keep away from each other on the surface each other respectively, and for the backup pad central line, turn button is located flexible loading mechanism's the outside, left side roof beam (3) and right side roof beam (4) one side that the upper end is close to each other is equipped with respectively and turns to mechanism (15) with the first direction touch panel and is located same height braking steering mechanism (15), be fixed with respectively on the one end face that braking steering mechanism (15) And when the electric push rod (20) drives the sliding table to drive the loading mechanism to slide back and forth along the length direction of the top beam, the first steering contact plate (124) is in contact with a steering button on the second steering contact plate (151) and extrudes the steering button, the steering button is triggered, and the electric push rod (20) changes the telescopic direction to form a reciprocating circulating sliding structure of the loading mechanism.
2. The dynamic loading model test device for high-speed rail foundations of an underlying underground engineering as claimed in claim 1, further comprising a controller (21), wherein the telescopic loading mechanism is provided with a pressure sensor for detecting the loading force of the telescopic loading mechanism, and the controller (21) is respectively connected with the driving part of the telescopic loading mechanism, the pressure sensor, the electric push rod (20) and the steering button (127).
3. The dynamic loading model test device for the high-speed rail foundation of the underlying underground engineering as claimed in claim 2, wherein the telescopic loading mechanism comprises a hydraulic jack (121) fixed on the bottom surface of the support plate (123) and extending and contracting along the vertical direction, an exciter support plate (125) extending and contracting along the hydraulic jack (121) is fixed on a movable part at the lower end of the hydraulic jack, an exciter (122) extending and contracting along the vertical direction is fixed on the lower surface of the exciter support plate (125), and a track pulley (18) matched with the track mechanism (16) is connected to the lower end of the exciter (122).
4. The dynamic loading model test device for high-speed railway foundation of underground engineering according to claim 3, wherein the track pulley (18) comprises a wheel axle support block (184) fixedly connected to the lower end of the vibration exciter, a wheel axle (181) rotatably mounted on the wheel axle support block (184), and wheel bodies (182) fixed at both ends of the wheel axle.
5. The dynamic loading model test device for high-speed rail foundation of underground engineering according to claim 2, wherein the filling space is paved with similar rock-soil bodies (23), the upper part of the similar rock-soil bodies (23) extends out of the filling space, and the similar rock-soil bodies of the extending part are paved with the track mechanism (16).
6. The dynamic loading model test device for high-speed rail foundation of the underlying underground engineering as claimed in claim 2, wherein the similar rock-soil body (19) is embedded with a tunnel precast block (11) or a goaf precast block (10) or a combination of the two, and a sensor (22) for monitoring dynamic stress, vibration acceleration or soil body settlement in the similar rock-soil body under dynamic load is also embedded in the similar rock-soil body.
7. A high-speed railway foundation dynamic loading model test device for an underlying underground engineering according to claim 1 or 2, wherein the left side beam (3) is provided with first pulleys (31) on the upper and lower end surfaces thereof, the base (2) is provided with first pulley rails (7) corresponding to the pulleys (31) on the upper surface and the top beam (5) on the lower surface thereof, the first pulleys (31) are slidably arranged in the first pulley rails to form a front-back sliding structure of the left side beam along the length direction of the base and the top beam, and the base (2) is provided with a second hydraulic jack (6) for driving the left side beam to slide.
8. The dynamic loading model test device for high-speed railway foundations of an underlying underground engineering as claimed in claim 7, characterized in that the side faces of the left side beam (3) and the right side beam (4) close to each other are provided with force-transmitting pressure plates (131) driven by third hydraulic jacks (13) for applying lateral stress.
9. A dynamic loading simulation test method for building underground engineering under an existing high-speed railway based on the test device of claim 4 is characterized by comprising the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode and burying corresponding sensors 22;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the method comprises the steps of disassembling a soil body limiting plate, excavating a supporting goaf or a subway tunnel at a corresponding position on a similar rock-soil body, enabling a loading mechanism (12) to reciprocate along a track mechanism under the condition of applying dynamic load, simulating the operation of an actual train, and monitoring the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock body through a sensor.
10. A dynamic loading simulation test method for operating existing underground engineering under a high-speed railway based on the test device of claim 4 is characterized by comprising the following steps:
step 1: measuring actual working conditions, carrying out equal-scale scaling on the high-speed railway roadbed and geological conditions by adopting a similar principle to obtain the sizes of corresponding similar rock-soil bodies, and adjusting the positions of the left side beams according to the sizes of the similar rock-soil bodies to enable the filling space to be matched with the sizes of the corresponding similar rock-soil bodies obtained by equal-scale scaling;
step 2: preparing materials of similar rock-soil bodies according to a similar principle; preparing a tunnel precast block (11) or a goaf precast block (10) by using corresponding similar materials to respectively simulate and replace a goaf or a subway tunnel of the existing underground engineering;
and step 3: laying similar rock-soil bodies in a filling space in a layered mode, burying corresponding sensors 22, and burying prefabricated tunnel prefabricated blocks (11) or gob prefabricated blocks (10) at corresponding positions;
and 4, step 4: after the similar rock-soil body of the model is stably consolidated, a track mechanism is laid above the similar rock-soil body;
and 5: spraying water above the similar rock-soil body to simulate natural precipitation;
step 6: the loading mechanism (12) reciprocates along the track mechanism under the condition of applying dynamic load, simulates the actual train operation, and monitors the settlement deformation of an upper track system or the dynamic stress and the vibration acceleration of a rock mass through a sensor.
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| CN113008493A (en) * | 2020-12-30 | 2021-06-22 | 中国矿业大学(北京) | Pipe piece model vibration test device |
| CN113884320A (en) * | 2021-09-16 | 2022-01-04 | 中铁西北科学研究院有限公司 | Device and method for simulating train load power test |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113008493A (en) * | 2020-12-30 | 2021-06-22 | 中国矿业大学(北京) | Pipe piece model vibration test device |
| CN113884320A (en) * | 2021-09-16 | 2022-01-04 | 中铁西北科学研究院有限公司 | Device and method for simulating train load power test |
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