Test device and method for simulating influence of rainfall on seepage dynamic of karst tunnel
Technical Field
The invention relates to the field of tunnel seepage model tests, in particular to a test device and a method for simulating dynamic influence of rainfall on a karst region tunnel seepage field.
Background
With the development of traffic construction in China, tunnel engineering is gradually built to areas with complex geological conditions, wherein karst water-rich areas occupy a certain proportion. In a karst area with complex hydrogeological conditions and developed cracks and pipelines, underground water around the tunnel is sourced from a water-bearing stratum, and the replenishment effect of atmospheric rainfall on underground water cannot be ignored due to the large amount of vertical karst pipelines. More importantly, the replenishment speed of atmospheric rainfall in the tunnel of the karst area is high, the consumed time is short, the relative insufficiency of the drainage capacity of the tunnel is easily caused, the water pressure outside the tunnel in a short time is overlarge, and the tunnel operation problems such as the deformation overrun of the inverted arch, the structural crack damage and the like are caused. Meanwhile, the above problems are mostly seen in domestic operation tunnels, which seriously affect the tunnel operation safety, and need to develop related research and discussion.
At present, tunnel water damage caused by precipitation is subjected to inversion analysis from engineering examples and numerical analysis. However, it is worth noting that, starting from engineering examples, systematic disease evolution laws are often difficult to obtain due to the limitation of field implementation conditions; from numerical analysis, it is difficult to ensure that the calculation model and boundary conditions are matched with the field situation. In recent years, similar model tests are often used for inversion research of tunnel diseases under rainfall conditions due to the fact that the similar model tests are convenient to operate and good in simulation similarity and can truly reduce the tunnel water damage. At present, a device for simulating tunnel defect inversion under rainfall is partially innovated:
for example, chinese patent publication No. CN 104330533B discloses a test apparatus and method for simulating tunnel surrounding rock collapse under rainfall and groundwater seepage, the apparatus includes a model test box, a rainfall simulation system with adjustable rainfall, a groundwater seepage simulation system, a groundwater supply system, a water content test system, a stress monitoring system, a digital photography non-contact measurement system and a fiber bragg grating displacement monitoring system. By simulating the gradual destruction process of the weak and broken surrounding rocks of the tunnel under the seepage action of surface water and underground water, the mechanical behavior of the broken surrounding rocks under different rainfall conditions and different underground water seepage paths is quantitatively researched. By obtaining multi-physical field information in the collapse process of the tunnel surrounding rock, analyzing the multi-information characteristics of different evolution stages of the collapse and the internal relation of each field information, and determining the progressive damage process, damage form and damage range of the tunnel weak and broken surrounding rock under different factors.
For another example, chinese patent publication No. CN206340266U discloses a model for comprehensively simulating a tunnel excavation process, which sequentially comprises a rainfall simulation box, a simulation box, and a water storage tank from top to bottom; the two ends of the simulation box are respectively connected with the water head control box, the two ends of the inside of the simulation box are respectively provided with a buffer stable area, and a simulation tunnel is also arranged in the middle simulation area; the simulation tunnel simulates the construction process of the tunnel, and the simulation box simulates the external environment in the construction process.
For another example, chinese patent publication No. CN 110275008A discloses a non-contact tunnel excavation physical model and a test method capable of simulating rainfall, where the model includes a tunnel segmental excavation simulation device, a controllable rainfall simulation device, and a test block full-surface displacement field observation device; the test method comprises the following steps: preparing a wax block layer and trimming and arranging to obtain wax blocks; filling soil and placing a wax block in the middle of the soil body; building a test block full-surface displacement field observation device and a controllable rainfall simulation device; a long rod excavating mechanism is adopted to simulate tunnel excavation; and observing the displacement change of the soil body by using the test block full-surface displacement field observation device.
However, on one hand, the above patent results do not consider topographic factors and formation karst characteristics, and can not simulate surface catchment effect and karst pipeline water flow characteristics, so that the test results are difficult to realize real reflection of actual cases; on the other hand, the above patent results are focused on experimental simulation of atmospheric rainfall during tunnel construction, and disease statistics show that the disease cases caused by rainfall after tunnel construction also occupy a large proportion, so it is necessary to perform experimental simulation on the tunnel after construction.
Disclosure of Invention
The invention aims to solve the problems in the prior art, provides a test device which can accurately simulate a karst area, reflect the dynamic change process of a seepage field, obtain an accurate seepage path, is convenient to use and simple in structure and is used for simulating the dynamic influence of atmospheric precipitation on the seepage field of a tunnel in the karst area, and also provides a method for testing the dynamic influence of the atmospheric precipitation on the seepage field of the tunnel in the karst area by using the test device for simulating the dynamic influence of the atmospheric precipitation on the seepage field of the tunnel in the karst area.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
the utility model provides a test device of simulation rainfall to karst tunnel seepage flow dynamic influence, including the test model case device that is used for simulating karst district and inside tunnel, be located test model case device top, a rainfall device for rainfall simulation, a test model case device for shoot, the full displacement field measuring device of non-contact of record seepage flow route, the simulation topography is connected on test model case device upper portion, the simulation topography is made by the topography mould, the simulation topography is located the below of rainfall device, simulation topography boundary and test model case device top boundary match.
Further, for improvement in the aspect of the mold, the terrain mold is a thin-layer shell with an inner cavity and an opening at the bottom and is used for fixing the shape and contour of the upper surface of the similar material of the surrounding rock to form a simulated terrain reflecting the actual landform, and the terrain mold is detachably connected to the upper part of the test model box device.
Further, for improving in the aspect of the test model box device, the test model box device comprises a model box, a tunnel model is arranged in the model box, tunnel contour holes matched with two ends of the tunnel model are formed in the outer surface of the model box, surrounding rock similar materials aiming at different geological conditions are filled in the model box in a layered mode, and at least one karst pipeline model is buried in the filled surrounding rock similar materials according to the test simulation requirements.
Furthermore, in order to cut the experimental model box, the improvement on the aspect of manufacturing the cross section of the seepage path is that a vertical clamping groove is arranged on the inner side surface of the model box, which is connected with the surface of the tunnel contour hole, in the middle position and is used for inserting a clamping groove plate.
Further, for being convenient for accept improvement in the aspect of the rain ware device, experimental model case device is the cuboid, and four angles of experimental model case device are equipped with the support column respectively, are equipped with four bracket poles that are located same level above the support column.
Further, in order to improve the function of adjusting the simulated rainfall, the rainfall device comprises a rainfall box, a pressure valve, a pressure pump, a water storage tank and a water conveying pipe connected between the rainfall box and the water storage tank; the rain falling box, the pressure valve, the pressure pump, the water pump and the water storage tank are sequentially connected end to end by each section of water conveying pipe, and the dyeing agent is put into water used by the rain falling device (2).
Furthermore, in order to improve the rainfall simulation under different rainfall conditions, the bottom of the rainfall tank is provided with rainfall holes which are uniformly distributed at intervals and matched with at least one rainfall spray head, and the rainfall spray heads are axially inserted along the rainfall holes.
Further, in order to improve the manufacturing of the test tool, the tunnel model, the karst pipeline model, the rainfall spray head and the terrain mould are all manufactured into an integral structure by adopting a 3D printing technology.
Further, for improvement in the aspect of photographing the seepage path, the non-contact full displacement field measuring device comprises a single lens reflex and a tripod for supporting the single lens reflex, wherein the single lens reflex is fixed on the upper part of the tripod.
The test method used by the test device for simulating the dynamic influence of rainfall on the seepage of the tunnel in the karst area specifically comprises the following steps,
s1: according to the requirements of a test for simulating the dynamic influence of atmospheric precipitation on a tunnel seepage field in a karst area, carrying out on-site survey on a simulated area, laying measurement control points, acquiring a terrain image by using unmanned aerial vehicles, and extracting data of the terrain image by using professional software;
s2: determining the size, position, form and related test parameters of a test model box device and a rainfall device to be researched according to the requirements of a test for simulating the dynamic influence of atmospheric rainfall on a karst region tunnel seepage field;
s3: determining the shapes, sizes and positions of a model box, a clamping groove, a supporting column, a bracket rod, a tunnel contour hole and a clamping groove plate according to the corresponding test parameters in the S2 and tunnel embedding conditions required by the test for simulating the dynamic influence of atmospheric precipitation on the karst region tunnel seepage field, and completing the manufacture; determining the shapes and sizes of a tunnel model and a karst pipeline model according to geological conditions and tunnel conditions required by a test for simulating the dynamic influence of atmospheric precipitation on a tunnel seepage field of a karst area, and manufacturing the tunnel model and the karst pipeline model one by adopting a 3D printing technology; establishing a terrain three-dimensional model according to the corresponding terrain data in the S1 and terrain conditions required by the experiment for simulating the dynamic influence of atmospheric precipitation on the karst region tunnel seepage field, and manufacturing a terrain mold by adopting a 3D printing technology;
s4: connecting the rainfall devices in sequence according to the requirements of simulating the dynamic influence of atmospheric rainfall on the seepage field of the tunnel in the karst region, placing a rainfall box on a bracket rod of the test model box device, and fixedly mounting a rainfall spray head; fixedly installing a non-contact full displacement field measuring device in the axial direction of the tunnel contour hole, and adjusting the distance between the test model box device and the non-contact full displacement field measuring device;
s5: according to the requirements of a test for simulating the dynamic influence of atmospheric precipitation on a tunnel seepage field of a karst area, surrounding rock similar materials under different geological conditions are filled in a model box in a layered mode, a tunnel model is axially inserted along a tunnel contour hole, a water pressure testing device is installed, and a karst pipeline model is installed in the surrounding rock similar materials; according to the requirements of a test for simulating the dynamic influence of atmospheric precipitation on a tunnel seepage field of a karst area, filling corresponding surrounding rock similar materials into an inner cavity of a terrain mold, horizontally placing the terrain mold on the upper part of a model box, and slowly taking off the terrain mold to form a simulated terrain;
s6: calculating the optimal concentration ratio of a coloring agent according to the requirement of a dynamic influence test of simulated atmospheric precipitation on a tunnel seepage field of a karst area, putting the coloring agent into a water storage tank, and preparing a coloring agent solution;
s7: according to the requirements of a test for simulating the dynamic influence of atmospheric precipitation on a karst area tunnel seepage field, slowly injecting water into the model box to a designed height, and simulating an initial water level;
s8: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area and the rainfall parameters required by the test, adjusting a pressure valve and a pressure pump, starting a water pump, and simulating rainfall;
s9: dynamic collection of test data: in the rainfall process, a non-contact full displacement field measuring device is adopted to dynamically acquire the full displacement field photos of the tunnel model, and dynamically acquire the tunnel drainage and the tunnel model water pressure;
s10: stopping rainfall after the rainfall reaches the rainfall time required by the test, and closing the rainfall device; after the test model box device is stabilized, excavating similar materials of surrounding rocks on one side layer by layer from the clamping groove position of the model box, vertically inserting the clamping groove plates layer by layer while excavating, shooting the cross section of the similar materials of the surrounding rocks exposed after excavation by using a single lens reflex after the similar materials of the surrounding rocks on one side are completely excavated and inserted into the clamping groove plates, and drawing a seepage path according to the distribution of coloring agents on the cross section.
S11: according to the requirements of simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area and rainfall parameters required by the test, adjusting a pressure valve and a pressure pump, changing a rainfall spray head according to the change of the test parameters, and repeating S5, S6, S7, S8, S9 and S10 to carry out a new rainfall parameter test.
Compared with the prior art, the invention has the advantages that:
in order to simulate the dynamic influence of atmospheric precipitation on the seepage field of a tunnel in a karst area, the invention provides a terrain mold which comprises a test model box device, a rainer device, a non-contact full displacement field measuring device and a terrain mold, wherein the rainer device is fixed above the test model box device and used for simulating rainfall, the non-contact full displacement field measuring device is fixed in front of the test model box device, and the terrain mold is horizontally placed between the test model box device and the rainer device, and the bottom of the terrain mold is closely attached to the upper boundary of the test model box device. When the device is used, test parameters of the test model box device, the rain falls device, the non-contact full-displacement field measuring device and the terrain mold are determined according to the rainfall condition, the geological condition and the terrain condition of a required simulation area, and compared with a seepage model test which only considers a single stratum condition and does not consider terrain factors under the simulated rainfall condition, the device greatly improves the accuracy of the model test, not only realizes the accurate simulation of the geological condition of a karst area, but also accurately restores the terrain of the simulation area; in addition, the device can obtain the dynamic change process of the seepage field and an accurate seepage path.
Drawings
FIG. 1 is a schematic diagram of a test device for simulating the dynamic influence of atmospheric precipitation on a karst region tunnel seepage field.
Fig. 2 is a schematic front view of a test simulation box and a rainer device of the present invention.
Fig. 3 is a schematic front view of the rainer device of the present invention.
Fig. 4 is a top view of the test simulation box of the present invention.
Fig. 5 is a schematic view of a card cage of the present invention.
Fig. 6 is a schematic view of a rain spray of the present invention.
Fig. 7 is a front view of the rain spray of the present invention.
Fig. 8 is a top view of the rain spray of the present invention.
Reference numerals: 1. a test model box device; 11. a model box; 12. a card slot; 13. a support pillar; 14. a bracket rod; 15. a tunnel model; 16. a karst pipeline model; 17. a tunnel contour hole; 18. a slot clamping plate; 19. a surrounding rock like material; 2. a raindrop device; 21. a rain box; 211. a rainfall hole; 212. a rainfall sprayer; 22. a pressure valve; 23. a pressure pump; 24. a water pump; 25. a water storage tank; 26. a water delivery pipe; 3. a non-contact full displacement field measuring device; 31. a single lens reflex camera; 32. a tripod; 4. and (5) forming a mold.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Examples
As shown in fig. 1, the test device for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area in the embodiment includes a test model box device 1, a rainer device 2 fixed above the test model box device 1 for simulating rainfall, a non-contact full displacement field measuring device 3 fixed in front of the test model box device 1, a terrain mold 4 horizontally placed between the test model box device 1 and the rainer device 2 and having a bottom closely attached to the upper boundary of the test model box device 1, the terrain mold 4 can be clamped above the test model box device 1 for convenient carrying and disassembly, the terrain mold 4 is used for fixing the upper surface shape contour of the surrounding rock similar material 19 to form a simulated terrain for reflecting the actual landform, the bottom boundary of the simulated terrain closely attached to the upper boundary of the test model box device 1 for facilitating the rainfall to fall into the test model box device 1 completely through the simulation, the simulation effect of the test is improved. The device greatly improves the accuracy of the model test, not only realizes the accurate simulation of the geological condition of the karst area, but also accurately restores the terrain of the simulation area; in addition, the device can obtain the result of the dynamic change of the seepage field and an accurate seepage path.
In order to obtain a seepage path, a vertical clamping groove 12 is arranged in the middle of two inner sides of a model box 11 of the test model box device 1, and after a seepage test is finished, soil on one side is excavated and inserted into a clamping groove plate 18, so that the soil on one side is kept stable and is made of surrounding rock similar materials 19. Four angles of experimental model case device 1 are equipped with support column 13 respectively, and support column 13 top is equipped with four bracket poles 14 that are in same level apart from model case 11 upper boundary 50cm department, and bracket pole 14 passes through welded connection with support column 13 for rainbox 21 fixed mounting is in the stability of testing model case device 1 top, assurance simulation precipitation. The model box 11 is also provided with a tunnel contour hole 17 matched with the tunnel model 15 for installing the tunnel model.
In order to simulate the geological conditions, the test model box device 1 is internally filled with surrounding rock similar materials 19 aiming at different geological conditions in a layered mode, and a karst pipeline model 16 is buried in the surrounding rock similar materials 19, so that the accuracy of simulating the geological conditions of a karst area is guaranteed.
In this embodiment, the rainer device 2 includes a raintank 21, a pressure valve 22, a pressure pump 23, a water pump 24, a water storage tank 25, and a water pipe 26 connected between the raintank 21 and the water storage tank 25. The rain-reducing tank 21, the pressure valve 22, the pressure pump 23, the water pump 24 and the water storage tank 25 are sequentially connected end to end through each water pipe 26, so that the simulated rainfall can be more finely controlled, and the stability and the uniformity of the rainfall are ensured. The rain case 21 bottom be equipped with evenly distributed and with rainfall shower nozzle 212 assorted rainfall hole 211, rainfall shower nozzle 212 inserts along rainfall hole 211 axial, guarantees the homogeneity of rainfall, and rainfall shower nozzle 212 is removable, is convenient for improve test device's utilization ratio, and other kinds also can be changed into to the rainfall shower nozzle, are favorable to improving the simulation effect.
In this embodiment, the non-contact full-displacement field measuring device 3 is composed of the single lens reflex 31 and the tripod 32 for fixedly supporting the single lens reflex 31, so as to realize dynamic monitoring of tunnel displacement and ensure the comprehensiveness, timeliness and accuracy of data acquisition. The single lens reflex 31 is fixed on the upper portion of the tripod 32, and the height and distance of the tripod 32 are adjusted, so that the measurement of the non-contact full displacement field measurement device 3 is adjustable.
In order to simulate the actual terrain, the terrain mould 4 is a thin-layer shell with an internal cavity and an opening at the bottom, the thickness is 4mm, the surrounding rock similar materials 19 can be conveniently filled, the real terrain of a simulated area can be formed, and the accuracy and operability of the simulated terrain can be guaranteed.
The tunnel model 15, the karst pipeline model 16, the rainfall spray nozzle 212 and the topographic mould 4 are all manufactured by adopting a 3D printing technology, and C-UV9400 photosensitive resin printing materials are preferably used. By adopting the technology, the manufacturing efficiency, the manufacturing precision and the dimensional stability of the device can be improved, the machinability is high, and the manufacturing is simple and easy to operate.
When the device is used for a test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area, the method comprises the following steps:
s1: extracting topographic data: according to the requirements of simulating atmospheric precipitation on a dynamic influence test of a tunnel seepage field in a karst area, carrying out on-site survey on a simulated area, laying measurement control points, acquiring a terrain image by using unmanned aerial vehicles, and extracting data of the terrain image by using professional software.
S2: determination of test parameters: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area, the test parameters such as the size, the position, the form and the like of the test model box device 1 and the rainfall device 2 to be researched are determined.
S3: production of the test model box device 1 and the topographic mold 4: determining the shapes, sizes and positions of the model box 11, the clamping groove 12, the supporting column 13, the bracket rod 14, the tunnel contour hole 17 and the clamping groove plate 18 according to the corresponding test parameters in the S2 and the tunnel burying conditions required by the test for simulating the dynamic influence of atmospheric precipitation on the karst region tunnel seepage field, and completing the manufacture; determining the shapes and the sizes of the tunnel model 15 and the karst pipeline model 16 according to geological conditions and tunnel conditions required by a test for simulating the dynamic influence of atmospheric precipitation on a karst area tunnel seepage field, and manufacturing the tunnel models one by adopting a 3D printing technology; and establishing a terrain three-dimensional model according to the corresponding terrain data in the S1 and terrain conditions required by the experiment for simulating the dynamic influence of atmospheric precipitation on the karst region tunnel seepage field, and manufacturing a terrain mold 4 by adopting a 3D printing technology.
S4: installation of the test device: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the seepage field of the tunnel in the karst region, sequentially connecting the rainfall device 2, placing the rainfall box 21 on the bracket rod 14 of the test model box device 1, and fixedly installing the rainfall spray head 212; and fixedly installing the non-contact full displacement field measuring device 3 in the axial direction of the tunnel contour hole 17, and adjusting the distance between the test model box device 1 and the non-contact full displacement field measuring device 3.
S5: stratum, tunnel and terrain simulation: according to the requirements of a test for simulating the dynamic influence of atmospheric precipitation on a tunnel seepage field of a karst area, surrounding rock similar materials 19 under different geological conditions are filled in a model box 11 in a layered mode, a tunnel model 15 is axially inserted along a tunnel contour hole 17, a water pressure testing device is installed, and a karst pipeline model 16 is installed in the surrounding rock similar materials 19; according to the requirements of the experiment for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area, the surrounding rock similar material 19 is filled in the cavity inside the terrain mold 4 and is horizontally placed on the upper part of the model box 11, and the terrain mold 4 is slowly taken off to form a terrain model.
S6: and (3) putting a coloring agent: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area, a brilliant blue coloring agent is selected, the optimal concentration ratio of the coloring agent is calculated, the coloring agent is put into a water storage tank 25, and brilliant blue coloring agent solution is prepared.
S7: initial water level simulation: according to the requirements of the experiment for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area, water is slowly injected into the model box 11 to the designed height, and the initial water level is simulated.
S8: rainfall simulation: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area and the rainfall parameters required by the test, the pressure valve 22 and the pressure pump 23 are adjusted, the water pump 24 is started, and rainfall simulation is carried out.
S9: dynamic collection of test data: in the rainfall process, the non-contact full displacement field measuring device 3 is adopted to dynamically collect the full displacement field photos of the tunnel model 15, and dynamically collect the tunnel water displacement and the water pressure of the tunnel model 15.
S10: obtaining a seepage path: stopping rainfall after the rainfall reaches the rainfall time required by the test, and closing the rainer device 2; after the model box device 1 is stabilized, surrounding rock similar materials 19 on one side are excavated layer by layer from the positions of the clamping grooves 12 of the model box 11, and the clamping groove plates 18 are vertically inserted layer by layer while excavating. After the surrounding rock similar material 19 on one side is excavated and inserted into the slot clamping plate 18, a single-lens reflex camera is adopted to shoot the section of the surrounding rock similar material 19 exposed after excavation, and a seepage path is drawn according to the distribution of the coloring agent on the section.
S11: adjustment of test parameters: according to the requirements of the test for simulating the dynamic influence of atmospheric precipitation on the tunnel seepage field of the karst area and the rainfall parameters required by the test, the pressure valve 22 and the pressure pump 23 are adjusted, the rainfall spray heads 212 are replaced according to the change of the test parameters, and the new rainfall parameter test can be carried out by repeating S5, S6, S7, S8, S9 and S10.
According to the method, the test parameters of the test model box device, the rainfall device, the non-contact full-displacement field measuring device and the terrain mold are determined according to the rainfall condition, the geological condition and the terrain condition of a required simulation area, and compared with the previous seepage model test which only considers a single stratum condition and does not consider terrain factors under the simulated rainfall condition, the accuracy of the model test is greatly improved, not only is the geological condition of a karst area accurately simulated, but also the terrain of the simulation area is accurately restored; in addition, the dynamic change process of the seepage field and the accurate seepage path can be obtained.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several equivalent substitutions or obvious modifications can be made without departing from the spirit of the invention, and all the properties or uses are considered to be within the scope of the invention.