Heat source device for monitoring seepage condition of dam foundation

Abstract

The utility model relates to a heat source device for monitoring the seepage condition of a dam foundation. The heat source device comprises a vertical monitoring pipe, a double-cavity temperature control water tank and a circulation control module. The vertical monitoring pipe is a round pipe, the bottom end of the vertical monitoring pipe is closed, the top end of the vertical monitoring pipe is open, the monitoring pipe is vertically arranged, and in actual engineering, the monitoring pipe is vertically arranged and buried in dam foundation covering layer soil in a hammering and driving mode. The double-cavity temperature control water tank and the circulation control module are used for periodically heating water in the water tank and circulating with water in the vertical monitoring pipe. According to the utility model, the dam foundation seepage of the earth and rockfill dam with the deep and thick covering layer can be automatically monitored, and the construction and maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to a heat source device for monitoring the seepage condition of a dam foundation. Background Technology

[0002] Dam projects often face challenges from complex geological conditions such as deep overburden layers, especially in southwestern my country where deep overburden foundations are common. Deep overburden layers typically refer to loose Quaternary sediments exceeding 30 meters in thickness, characterized by loose structure, discontinuous lithology, and high permeability. During dam operation, seepage is not limited to the dam body; seepage in the dam foundation soil also requires close monitoring.

[0003] When planning and constructing dams on thick overburden layers, earth-rock dams are often the preferred type due to their less susceptibility to geological conditions and wide applicability. Currently, dam seepage monitoring primarily focuses on the dam body, mainly due to two reasons: first, the dam foundation often rests directly on hard bedrock, resulting in minimal seepage at the foundation; second, the foundation is typically treated with anti-seepage measures, further reducing the possibility of abnormal seepage. However, when encountering thick overburden layers and excavation costs are high, making it impossible to place the dam foundation directly on bedrock, the risk of seepage damage to the dam foundation caused by the thick overburden layer must be fully considered. For earth-rock dams built on thick overburden layers, foundation seepage monitoring is crucial.

[0004] Utility model patent CN109856032B discloses a mobile distributed seepage monitoring system and method using a point heat source, which combines a fiber optic temperature sensor with a point heat source for seepage monitoring. However, it has the following drawbacks:

[0005] (1) The monitoring pipes are arranged horizontally along the axial direction, which makes construction difficult. For example, for seepage monitoring of existing projects or deep overburden layers, it is necessary to excavate to the required depth before the monitoring pipes can be installed, which results in high installation costs and low applicability.

[0006] (2) During the monitoring process, the heating module needs to heat the surrounding soil to a certain temperature. As the heat generated by the heating module during the heating process is continuously carried away by the seepage water or diffused to the surrounding area, in order to heat the soil to the required temperature in a short time, the heating module needs to meet a certain heating power. If there are many sensors in series at this time, the total heating power required will be too high, which puts high requirements on the power of the power supply system and the cable bearing capacity. Summary of the Invention

[0007] To address the problems existing in the background technology, this utility model proposes a heat source device for monitoring the seepage condition of dam foundation, thereby enabling the monitoring of seepage in the foundation of earth-rock dams with deep overburden layers and reducing construction and maintenance costs.

[0008] The technical solution of this utility model to solve the above problems is: a heat source device for monitoring the seepage condition of a dam foundation, which is special in that:

[0009] It includes a vertical monitoring tube and a dual-chamber temperature-controlled water tank and circulation control module.

[0010] The vertical monitoring tube is a circular tube with a closed bottom and an open top. The monitoring tube is arranged vertically. In actual engineering, the monitoring tube is arranged vertically and buried in the dam foundation overburden soil by hammering.

[0011] The dual-chamber temperature-controlled water tank and circulation control module are used to periodically heat the water in the water tank and circulate it with the water in the vertical monitoring pipe.

[0012] Furthermore, the aforementioned vertical monitoring tube is made of circular steel pipe.

[0013] Furthermore, to facilitate driving the vertical monitoring tubes into the dam foundation overburden, the bottom of the tubes is processed into a conical shape.

[0014] Furthermore, a temperature-measuring optical fiber is inserted into the aforementioned vertical monitoring tube to monitor the temperature data inside the tube in real time.

[0015] Furthermore, the aforementioned dual-chamber temperature-controlled water tank and circulation control module includes a dual-chamber temperature-controlled water tank and a water circulation control component; the dual-chamber temperature-controlled water tank contains two water compartments, each of which is equipped with a heating device, and the heating temperature can be set as needed; the water circulation control component includes a pipeline and a bidirectional water pump, the upper end of the pipeline is connected to the water compartment, the lower end is connected to the bottom of the vertical monitoring pipe, and a bidirectional water pump is installed in the middle to inject hot water from the water compartment into the vertical monitoring pipe, or to draw cooled cold water from the vertical monitoring pipe into the water compartment.

[0016] Furthermore, the aforementioned water circulation control component also includes an electromagnetic three-way valve, which is located between the water tank and the water pump and is used to control the water passage.

[0017] Furthermore, an insulation layer is installed on the outside of the water tank to prevent heat loss inside the tank.

[0018] Advantages of this utility model:

[0019] The monitoring tube of the device provided by this utility model is arranged vertically and can be directly driven in with a hammer, eliminating the need for excavation, making construction convenient, cost-effective, and simple in structure, and easy to maintain later. The device provides a dual-chamber temperature-controlled water tank for periodic circulating heating of water, requiring low heating power and having low requirements for the power supply system. The temperature-controlled water tank is in a closed state, resulting in low energy loss during heating; the heated water can be quickly injected into the monitoring tube in a short time, with high heat source control accuracy and good monitoring accuracy. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall layout of the monitoring device provided by this utility model;

[0021] Figure 2 A schematic diagram of the dual-chamber temperature-controlled water tank and circulation control module in the monitoring device provided by this utility model. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0023] This utility model proposes an automatic monitoring device for dam foundation flow velocity based on an artificial heat source, the basic structure and layout of which are as follows: Figure 1 As shown, the device mainly includes a vertical monitoring tube and a dual-chamber temperature-controlled water tank and circulation control module. The vertical monitoring tube is a circular tube with a closed bottom and an open top, and the monitoring tube is arranged vertically.

[0024] In some embodiments provided by this utility model, specifically, the vertical monitoring tube is made of a circular (e.g., 8cm in diameter) steel pipe, closed at the bottom and open at the top. See also Figure 1 In actual engineering, the monitoring pipes are arranged vertically and buried in the dam foundation overburden soil by hammering.

[0025] To facilitate insertion, the bottom of the monitoring tube should preferably be tapered. The length of the monitoring tube needs to be determined based on the monitoring depth required for the actual project. In earth-rock dam projects with deep overburden, seepage monitoring tubes can be placed in the overburden layer on the downstream side of the dam body to monitor the seepage status of key parts of the dam foundation.

[0026] In some embodiments provided by this utility model, such as Figure 2 As shown, the dual-chamber temperature-controlled water tank and circulation control module consists of two parts: a dual-chamber temperature-controlled water tank and a water circulation control component. It is used to periodically heat the water in the water tank and circulate it with the water in the monitoring tube.

[0027] Specifically, the dual-chamber temperature-controlled water tank comprises two water compartments, denoted as compartment A and compartment B. Each compartment is equipped with a heating device, and the heating temperature can be set as needed (e.g., 60℃). The volume of each compartment must be greater than the volume of water required to fill the monitoring tube. For example, when the monitoring tube diameter is 8cm and the monitoring depth is 20m, the water compartment volume needs to be 0.1m³. 3 about.

[0028] In a preferred embodiment, an insulation layer is provided on the outside of the water tank to prevent heat loss inside the tank.

[0029] Specifically, the water circulation control component includes pipelines, a bidirectional water pump, and a solenoid three-way valve. The upper end of the pipeline connects to the water tank, and the lower end connects to the bottom of the monitoring pipe. A bidirectional water pump is installed in the middle to inject hot water from the water tank into the monitoring pipe, or to pump cooled water from the monitoring pipe into the water tank. In addition, a solenoid three-way valve is installed between tanks A and B and the water pump to control the water flow, such as connecting "tank A - monitoring pipe" or "tank B - monitoring pipe". This component can automatically operate according to the required time interval (e.g., 6 hours), starting the water pump to circulate water between the two water tanks and the monitoring pipe.

[0030] A complete pumping and injection cycle is as follows:

[0031] Warehouse A is filled with water and heated to the required temperature. The solenoid three-way valve is connected to the "Ward A - Monitoring Tube" connection. The water pump is started to inject hot water from Warehouse A into the monitoring tube, and the cooling process of the water in the monitoring tube is measured. After a preset time interval, the water pump is started to pump the cold water in the monitoring tube back to Warehouse A. After extraction is complete, Warehouse A starts heating and switches the valve to connect to the "Ward B - Monitoring Tube" connection, injecting hot water from Warehouse B into the monitoring tube to monitor the cooling curve. After a preset time interval, the cold water in the monitoring tube is pumped back to Warehouse B; Warehouse B starts heating and switches the valve to connect to the "Ward A - Monitoring Tube" connection for the next cycle.

[0032] The working mechanism of the automatic dam foundation flow velocity monitoring device based on artificial heat source proposed in this utility model is as follows:

[0033] In earth-rock dam projects with deep overburden, monitoring locations and depths are selected, and prefabricated cone-shaped bottom-sealed monitoring pipes are vertically driven into the soil. Temperature-measuring optical fibers and water pipes are then inserted into the monitoring pipes. Figure 1 As shown, the temperature-measuring optical fiber and water pipe are connected to the "dual-cavity temperature-controlled water tank and circulation control module" respectively, and the optical fiber temperature measurement host is connected to the temperature-measuring optical fiber to realize real-time, online and continuous temperature monitoring.

[0034] The testing principle of this device is based on the coupling effect of the seepage field and the temperature field. It quantitatively determines the soil seepage state by measuring the temperature inside the temperature measuring tube. A temperature difference exists between the hot water inside the monitoring tube and the surrounding soil. Under the action of seepage in the soil, the heat inside the monitoring tube is transferred to the surroundings through heat conduction and convection, and the water temperature inside the tube gradually decreases. When there is no seepage or the seepage velocity in the soil is low, the temperature decrease rate inside the tube is slow; as the seepage velocity in the soil increases, the temperature decrease rate inside the tube changes. Based on this principle, abnormal seepage conditions can be identified, and the seepage velocity in the soil can be quantitatively assessed based on the cooling curve.

[0035] This device utilizes the above principle to periodically inject hot water into the monitoring tube according to a predetermined program. It uses distributed fiber optic temperature sensors to record the cooling process of the water in the tube, and then judges the seepage state and calculates the seepage rate based on the cooling curve.

[0036] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Those skilled in the art can still adjust the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Therefore, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalents, the present utility model also intends to include these modifications and variations.

Claims

1. A heat source device for monitoring seepage conditions in dam foundations, characterized in that: Includes a vertical monitoring tube and a dual-chamber temperature-controlled water tank and circulation control module; The vertical monitoring tube is a circular tube with a closed bottom and an open top, and the monitoring tube is arranged vertically. The dual-chamber temperature-controlled water tank and circulation control module are used to periodically heat the water in the water tank and circulate it with the water in the vertical monitoring pipe.

2. The heat source device for monitoring seepage conditions in a dam foundation according to claim 1, characterized in that: The vertical monitoring tube is made of circular steel pipe.

3. The heat source device for monitoring seepage conditions in a dam foundation according to claim 2, characterized in that: The bottom of the vertical monitoring tube is machined into a cone shape.

4. A heat source device for monitoring seepage conditions in a dam foundation according to any one of claims 1-3, characterized in that: The dual-chamber temperature-controlled water tank and circulation control module includes a dual-chamber temperature-controlled water tank and a water circulation control component; The dual-chamber temperature-controlled water tank comprises two water compartments, each equipped with a heating device, and the heating temperature can be set as needed; The water circulation control component includes a pipeline and a bidirectional water pump. The upper end of the pipeline is connected to the water tank, and the lower end is connected to the bottom of the vertical monitoring pipe. The bidirectional water pump is installed in the middle to inject hot water from the water tank into the vertical monitoring pipe, or to draw cooled cold water from the vertical monitoring pipe into the water tank.

5. A heat source device for monitoring seepage conditions in a dam foundation according to claim 4, characterized in that: The water circulation control component also includes an electromagnetic three-way valve, which is located between the water tank and the water pump to control the water passage.

6. A heat source device for monitoring seepage conditions in a dam foundation according to claim 5, characterized in that: An insulation layer is installed on the outside of the water tank to prevent heat loss inside the tank.

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