A method for preventing mud and water inrush in tunnels and a temperature measuring device

Abstract

The present invention discloses a method for preventing mud and water inrush in tunnels and a temperature measuring device, belonging to the technical field of tunnel construction. The method includes the following steps: Step 1, drill temperature measuring holes in the surrounding rock of the tunnel; Step 2, obtain the rock temperature measurement value B in the temperature measuring holes; Step 3, compare the rock temperature measurement value B with the normal value A of the rock mass temperature, and judge the possibility of mud and water inrush in the tunnel according to whether the comparison result exceeds the set threshold, so as to give an early warning of mud and water inrush in the tunnel. Through the pipe fittings with a detachable structure, the rock temperature at different depths can be measured, and the applicable range is wider. The pipe fittings are connected by several pipe fittings and can be flexibly shortened or lengthened, which is convenient for deployment and retraction in the tunnel. By setting the temperature detection element and the pressure detection element, multiple temperature points in the temperature measuring holes can be measured simultaneously, providing detailed data for the temperature gradient of the surrounding rock.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and particularly relates to a method for preventing mud and water inrush in tunnels and a temperature measuring device. Background Art

[0002] With the rapid development of China's national economy and the high-speed development of its highway and railway construction, the general trend of tunnel construction has become a trend. A large number of high geothermal tunnels and cold region tunnels are newly built, and the geological conditions passed through by the tunnels are more complex. When encountering large-scale underground rivers, water-filled karst caves and solution pipes and other water-bearing bodies, karst water inrush disasters are extremely likely to occur. It not only affects the construction safety and progress, the health of employees cannot be guaranteed, the mechanical efficiency is reduced, and in severe cases, it may even lead to engineering accidents, causing major accidents such as property losses and casualties.

[0003] Currently, the methods commonly used for predicting mud and water inrush in tunnels are: geological analysis method, drilling water exploration method, electromagnetic wave detection method, rock mass temperature method, seismic wave reflection method, infrared detector method, transient electromagnetic method, etc. Due to the complex tunnel environment and the multi-solution nature of these methods themselves, the prediction effect is not ideal. In recent years, a method of predicting the water body in front of the heading face by measuring the temperature change of the heading face has been proposed and gradually applied to production practice. This method is welcomed on site because of its simplicity, effectiveness and strong real-time performance. Whenever mud and water inrush occur in front of the heading face, the temperature of the heading face rock will gradually decrease as the excavation approaches the water body in front. The water and mud inrush in front can be predicted by tracking and measuring the rock temperature of the heading face. Based on this, the present application proposes a method for warning of mud and water inrush in tunnels based on the rock temperature of the tunnel heading face. Summary of the Invention

[0004] On the one hand, in order to solve the problems of the prior art, the present invention provides a method for preventing mud and water inrush in tunnels, and the method includes the following steps:

[0005] Step 1: Drill temperature measuring holes in the surrounding rock in the tunnel;

[0006] Step 2: Obtain the rock temperature measurement value B in the temperature measuring hole;

[0007] Step 3: Compare the rock temperature measurement value B with the normal value A of the rock mass temperature, and judge the possibility of mud and water inrush in the tunnel according to whether the comparison result exceeds the set threshold, so as to give a warning of mud and water inrush in the tunnel. Specifically:

[0008] If the rock temperature measurement value B + judgment factor M is greater than the normal value A of the rock mass temperature, the water-rich situation of the tunnel is normal, and continue to measure the rock temperature value B;

[0009] If the rock temperature measurement value B + judgment factor M is less than or equal to the normal value A of the rock mass temperature, there is a possibility of water and mud inrush.

[0010] Furthermore, the normal value A of the rock mass temperature is the normal average value of the rock mass temperature under the geothermal gradient theory.

[0011] Furthermore, the calculation method of the normal average value of the rock mass temperature is as follows:

[0012] T PR = T S + G loc * d + ΔT yopo

[0013] Wherein, T S — The temperature of the ground point directly above this point in the tunnel;

[0014] d — The burial depth of the tunnel at this point;

[0015] G loc — The geothermal gradient;

[0016] ΔT topo — The three-dimensional terrain effect of the ground point directly above this point in the tunnel.

[0017] Furthermore, the judgment factor M = 5.

[0018] Furthermore, the rock temperature value B is the average value of the temperature values of multiple points in the temperature measurement hole.

[0019] On the other hand, the present invention provides a temperature measuring device, and the device includes:

[0020] A measuring pipe fitting, on which a temperature detection element and a pressure detection element are arranged;

[0021] The temperature detection element and the pressure detection element are respectively used to measure the rock temperature and water pressure in the hole;

[0022] A display, which has a built-in controller and a memory;

[0023] The display and the memory are both connected to the controller, and the controller is connected to the pressure detection element and the temperature detection element.

[0024] Furthermore, the measuring pipe fitting includes: a plurality of connecting pipes connected in sequence;

[0025] On the wall of each connecting pipe, the temperature detection element and the pressure detection element are arranged, and on the outer end of the connecting pipe at the end, the temperature detection element and the pressure detection element are arranged.

[0026] Furthermore, grooves are arranged on the wall / end of the connecting pipe, and springs are arranged in the grooves;

[0027] One end of the spring is connected to the inner wall of the connecting pipe, and a shrapnel is connected to the other end of the spring. The temperature detection element and the pressure detection element are arranged on the surface of the shrapnel.

[0028] Further, the shrapnel is a polytetrafluoroethylene shrapnel.

[0029] Further, scale lines are arranged on one side of the connecting pipe.

[0030] Advantages of the present invention:

[0031] By opening a hole near the heading face, measuring the cooling change rate in the hole, and measuring the water pressure in the hole, combined with the normal field of the temperature observation data, by comparing whether the actually observed cooling change rate deviates from the normal field by a certain amplitude, it is determined in turn whether there will be accidents of water inrush and mud inrush ahead.

[0032] Through the pipe fittings with a detachable structure, the rock temperature at different depths can be measured, and the applicable range is wider. The pipe fittings are connected by several pipe fittings, which can be flexibly shortened or lengthened, facilitating deployment and retraction in the tunnel. By setting the temperature detection element and the pressure detection element, multiple temperature points in the temperature measurement hole can be measured simultaneously, providing detailed data for the temperature gradient of the surrounding rock. By setting the spring, the temperature detection element and the pressure detection element can be closely attached to the surrounding rock to ensure accurate temperature measurement. In addition, the heat insulation and heat preservation structure makes the measurement data more accurate, and the buried construction steps are simple, enabling rapid installation and effective temperature measurement. Description of the drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is a three-dimensional structure schematic diagram of the pipe fitting provided by the present invention;

[0035] Figure 2 It is a side structure schematic diagram provided by the present invention;

[0036] Figure 3 It is a connection structure schematic diagram of the detection element provided by the present invention;

[0037] Figure 4 It is a temperature measurement process schematic diagram provided by the present invention.

[0038] Reference numerals: 1 is a measuring pipe fitting, 2 is a temperature detecting element, 3 is a pressure detecting element, 4 is a shrapnel, 5 is a scale line, 6 is a spring, 7 is a piezometer data line, 8 is a thermistor data line, and 9 is a data transmission cable trough. Detailed implementation mode

[0039] To make the objectives, technical solutions and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail with reference to the drawings.

[0040] See Figures 1 to 3 , the present invention provides a temperature measuring device, and the device includes:

[0041] A measuring pipe fitting 1, on which a temperature detecting element 2 and a pressure detecting element 3 are arranged;

[0042] The temperature detecting element 2 and the pressure detecting element 3 are respectively used to detect the rock temperature and water pressure in the measuring hole;

[0043] A display, which has a built-in controller and a memory;

[0044] Both the display and the memory are connected to the controller, and the controller is connected to the pressure detecting element 3 and the temperature detecting element 2; wherein, the controller and the memory can be installed inside the measuring pipe fitting or be integrally arranged with the display outside;

[0045] The controller is used to convert the signals detected by the temperature detecting element and the pressure detecting element into numbers and images and display them on the display screen, and at the same time store the received information in the memory.

[0046] In some embodiments, the measuring pipe fitting 1 includes: a plurality of connecting pipes connected in sequence;

[0047] The temperature detecting element 2 and the pressure detecting element 3 are arranged on each of the connecting pipes, and the temperature detecting element 2 and the pressure detecting element 3 are arranged at the outer end of the connecting pipe at the end.

[0048] Among them, the length of a single connecting pipe is 1 m, and the two connecting pipes are connected by a threaded two-way rotary joint. The material of the connecting pipe is selected as aluminum-lithium alloy.

[0049] The pipe thread joint mainly plays a connecting role. The two-way rotary joint can enhance the flexibility and reliability of the pipeline system, is easy to operate and improves the use safety.

[0050] In some embodiments, grooves are arranged on the pipe wall / the end of the connecting pipe, the grooves penetrate the pipe wall of the connecting pipe, and a spring 6 is arranged in the grooves;

[0051] One end of the spring 6 is connected to the inner wall of the connecting pipe, and the other end of the spring 6 is connected with a shrapnel 4. The temperature detection element 2 and the pressure detection element 3 are fixedly connected to the surface of the shrapnel 4.

[0052] Among them, the temperature detection element is a platinum metal thermistor, and the pressure detection element is a piezometer. The platinum metal thermistor element has high precision, simple structure, small volume, light weight, is easy to install and use, and can provide very accurate temperature measurement results.

[0053] The platinum metal thermistor is connected to the controller through the thermistor data line 8, and the piezometer is connected to the piezometer through the piezometer data line 7. In order to facilitate the routing of the data line inside the pipe fitting, a data line transmission wire groove 9 is provided on the inner wall of the connecting pipe.

[0054] The spring can ensure that the platinum metal thermistor is in close contact with the surrounding rock, making the temperature measurement of the platinum metal thermistor more accurate.

[0055] In some embodiments, the shrapnel 4 is a polytetrafluoroethylene (PTFE) shrapnel 4.

[0056] Among them, the shrapnel is made of a material with poor thermal conductivity, polytetrafluoroethylene (PTFE), for installing and fixing the piezometer and the platinum metal thermistor, and avoiding using materials with better thermal conductivity, because the thermal conductivity will directly affect the accuracy of the measurement value of the platinum metal thermistor.

[0057] In some embodiments, scale lines 5 are provided on one side of the connecting pipe.

[0058] Among them, the function of the scale line is to facilitate viewing the depth of the measuring pipe fitting extending into the temperature measuring hole, so as to facilitate accurately measuring the rock temperature at different depths. The minimum scale of the scale line is 1 millimeter.

[0059] See Figure 4 , the present invention provides a method for preventing mud and water inrush in tunnels. The method includes the following steps:

[0060] Step 1: Drill a temperature measuring hole in the surrounding rock in the tunnel;

[0061] Step 2: Obtain the rock temperature value B in the temperature measuring hole;

[0062] By inserting the measuring pipe fitting deep into the temperature measuring hole (where the diameter of the temperature measuring hole is larger than that of the pipe fitting, which can ensure that when the measuring pipe fitting enters the temperature measuring hole, the platinum metal thermistor and the osmometer will not rub against the rock), until the platinum metal thermistor and the osmometer at the end of the measuring pipe fitting contact the bottom of the temperature measuring hole, and then operating the measuring pipe fitting to make all the platinum metal thermistors and osmometers contact the inside of the temperature measuring hole, and then sealing the hole of the temperature measuring hole with heat-insulating and heat-preserving material phenolic foam (to avoid inaccurate measurement results caused by the temperature difference between the outside and the inside of the temperature measuring hole);

[0063] Step 3: If the measured rock temperature value B + the judgment factor M is greater than the normal rock mass temperature value A, the water-rich situation of the tunnel is normal, and continue to measure the rock temperature value B;

[0064] If the measured rock temperature value B + the judgment factor M is less than or equal to the normal rock mass temperature value A, there is a possibility of water and mud inrush, then it can be determined that the rock cooling change rate belongs to a sharp increase, and there is an event of water and mud inrush.

[0065] Among them, M = 5. According to the statistics and analysis of the monitoring data, a sudden temperature drop of 5°C can predict water and mud inrush; less than 5°C means there is a small amount of water that does not threaten construction safety. In addition, the rock temperature value B is the average value of the temperature values at multiple points in the temperature measuring hole, and the normal rock mass temperature value A is the normal average value of the rock mass temperature under the geothermal gradient theory;

[0066] The normal average value of the rock mass temperature is:

[0067] T PR =T S +G lot *d+ΔT topo

[0068] In the formula, T S —— The temperature (°C) of the ground point directly above this point in the tunnel;

[0069] d—— The buried depth (m) of the tunnel at this point;

[0070] G loc —— The geothermal gradient (°C / m);

[0071] ΔT topo —— The three-dimensional terrain effect (°C) of the ground point directly above this point in the tunnel.

[0072] In addition, the present invention forecasts hazards such as water and mud inrush ahead by judging the difference between the measured temperature of the rock mass and the theoretical temperature of the rock mass. The measured pressure data is convenient for assisting in judging hazards such as water and mud inrush ahead. According to the engineering geological conditions, hydrogeological conditions, relevant experience and standards, the water pressure threshold value of the surrounding rock is determined. If the measured water pressure value exceeds the water pressure threshold value of the surrounding rock, the risk of water and mud inrush ahead of the tunnel can be judged, and numerical calculations are not performed in the actual process.

[0073] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A warning method for mud and water inrush in tunnels, characterized in that, The method includes the following steps: Step 1: Drill temperature measurement holes in the surrounding rock in the tunnel; Step 2: Obtain the rock temperature measurement value B in the temperature measurement holes; Step 3: Compare the rock temperature measurement value B with the normal rock mass temperature value A, and judge the possibility of tunnel mud and water inrush according to whether the comparison result exceeds the set threshold, so as to conduct early warning of tunnel mud and water inrush. Specifically: If the rock temperature measurement value B + judgment factor M is greater than the normal rock mass temperature value A, the water-rich condition of the tunnel is normal, and continue to measure the rock temperature value B; If the rock temperature measurement value B + judgment factor M is less than or equal to the normal rock mass temperature value A, there is a possibility of water and mud inrush; The normal rock mass temperature value A is the normal average value of the rock mass temperature under the geothermal gradient theory, and the calculation method of the normal average value of the rock mass temperature is: T PR = T S + G loc * d + ΔT topo Among them, T S - The temperature of the ground point directly above this point in the tunnel; d - the burial depth of the tunnel at this point; G loc - Geothermal gradient; ΔT topo - Three-dimensional terrain effect of the ground point directly above this point in the tunnel.

2. The early warning method for tunnel mud and water inrush according to claim 1, characterized in that The judgment factor M = 5.

3. The early warning method for tunnel mud and water inrush according to claim 1, characterized in that, The rock temperature value B is the average value of the temperature values at multiple points in the temperature measurement holes.

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