Faced rockfill dam subbase structure, faced rockfill dam system and intelligent monitoring subbase system

Abstract

This utility model belongs to the technical field of panel rockfill dams, specifically relating to a panel rockfill dam cushion layer structure, a panel rockfill dam system, and an intelligent monitoring cushion layer system. It includes: a polyurethane elastic cushion layer, which consists of a base layer and a surface layer; the base layer is high-elasticity polyurethane permeable concrete with an elastic modulus of 10-20 MPa, a porosity of 20%-25%, and a compressive strength ≥15 MPa; the surface layer is a self-healing polyurethane coating with a thickness of 2-3 mm, an elongation at break ≥500%, and the ability to self-heal cracks smaller than 0.3 mm. This utility model adopts a gradient structure of "high-elasticity polyurethane permeable concrete base layer + self-healing polyurethane coating surface layer," effectively avoiding risks such as seepage damage and frost heave cracking, increasing the dam's anti-sliding stability safety factor by 15%, and comprehensively ensuring the structural safety of the dam.

Description

Technical Field

[0001] This utility model belongs to the field of panel rockfill dam technology, specifically relating to a panel rockfill dam cushion layer structure, a panel rockfill dam system, and an intelligent monitoring cushion layer system. Background Technology

[0002] Currently, most rockfill dams with concrete panels use gravel or ordinary concrete as the foundation material. However, long-term engineering practice has revealed the following technical bottlenecks in the foundation material of rockfill dams: (1) Permeability control problem: Due to the material properties, the sand and gravel cushion layer has a porosity of 25%-35%, resulting in a seepage flow rate as high as 0.5-1.0L / (m・d). Under the action of high water head (>100m), seepage failure is very likely to occur. For example, in a certain actual project, the seepage gradient of the cushion layer exceeded the allowable value, which directly led to the occurrence of piping accident.

[0003] (2) Complex construction process: Traditional subbase construction requires strict implementation of layered compaction process, with each layer thickness controlled at 200-300mm and a compaction degree requirement of ≥98%, which makes the construction efficiency extremely low. Taking a 50m high dam as an example, the subbase construction time accounts for 30% of the total construction period, which seriously affects the overall progress of the project.

[0004] (3) Durability limitations: Ordinary concrete cushion layers have weak resistance to freeze-thaw cycles, with a cycle count of <200 times. In severe cold environments below -20℃, they are prone to frost heave and cracking. For example, the frost heave of the cushion layer of a dam in Northwest China has reached 30mm, which seriously threatens the safety of the dam.

[0005] (4) Poor adaptability to deformation: Under the action of its own weight, water load, etc., the rockfill will settle and deform, and the deformation can reach 1%-2% of the dam height. Traditional cushion layers cannot adapt to this deformation and are prone to cracking. In a certain project, the width of the crack in the cushion layer was >3mm, which directly caused the leakage to increase by 5 times.

[0006] (5) Environmental protection and cost contradiction: gravel cushion layer requires quarrying to obtain raw materials, which causes great disturbance to the ecological environment; at the same time, its comprehensive cost is 15%-20% higher than that of polyurethane cushion layer, which is not economically viable. Utility Model Content

[0007] The purpose of this utility model is to provide a panel rockfill dam subbase structure, a panel rockfill dam system, and an intelligent monitoring subbase system to solve the problems existing in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a panel rockfill dam cushion layer structure, comprising: A polyurethane elastic padding layer, wherein the polyurethane elastic padding layer is composed of a base layer and a surface layer; The base layer is high-elasticity polyurethane permeable concrete with an elastic modulus of 10-20 MPa, a porosity of 20%-25%, a compressive strength ≥15 MPa, and a permeability coefficient of 1×10⁻³~1×10⁻ 4 cm / s; The surface layer is a self-healing polyurethane coating with a thickness of 2-3 mm and an elongation at break of ≥500%, capable of self-healing cracks smaller than 0.3 mm.

[0009] Preferably, shape memory alloy fibers are embedded in the base layer, and the pre-strain of the shape memory alloy fibers is 5%-10%, which is used to automatically shrink to compensate for deformation when the strain of the pad layer exceeds 0.5%.

[0010] Preferably, the polyurethane elastic pad layer also contains a nano-SiO2 modifier at a dosage of 3%-5% to improve corrosion resistance.

[0011] Preferably, an interface reinforcement layer is provided between the cushion layer and the rockfill body. The interface reinforcement layer is a silane coupling agent layer sprayed on the surface of the rockfill body, with a penetration depth ≥5mm and an interface bonding strength ≥1.5MPa.

[0012] Preferably, the bottom of the cushion layer is further provided with a mortar cushion layer with a thickness of 50mm, a compressive strength of ≥25MPa, an interface roughness Ra≥50μm, and equipped with mechanical anchor bars with a spacing of 500mm.

[0013] Preferably, the polyurethane elastic pad has internal drainage channels with a spacing of 2-3m to control the seepage flow rate to be less than 0.1L / (m·d).

[0014] Preferably, it also includes a siphon drainage system for automatically initiating drainage when the water pressure inside the cushion layer exceeds 0.1 MPa.

[0015] This utility model also discloses a panel rockfill dam system, including a rockfill body and a cushion layer located thereon, wherein the cushion layer is the polyurethane elastic cushion layer.

[0016] This utility model also discloses an intelligent monitoring subbase system for panel rockfill dams, comprising: The aforementioned polyurethane elastic pad; A distributed optical fiber sensor, wherein the distributed optical fiber sensor is embedded inside the polyurethane elastic pad layer; A piezometer, which is installed inside or downstream of the cushion structure, is used to monitor uplift pressure.

[0017] Preferably, it also includes an unmanned aerial vehicle (UAV) infrared thermal imaging inspection unit for detecting cracks and voids in the surface layer of the padding from the outside.

[0018] The beneficial effects of this utility model are: This utility model adopts a gradient structure of "high elastic polyurethane permeable concrete base layer + self-healing polyurethane coating surface layer", and the base layer achieves a reverse filtration function of "water permeable but soil impermeable" (permeability coefficient 1×10⁻³-1×10⁻ 4 The surface layer can self-heal cracks smaller than 0.3 mm and withstand more than 500 freeze-thaw cycles. Combined with the deformation self-compensation of shape memory alloy fibers (response time <10 seconds when strain exceeds 0.5%) and the corrosion resistance improvement of nano-SiO2 modification (resistance to salt spray corrosion up to 2000 hours), the seepage flow of the cushion layer is reduced to <0.1L / (m・d) (90% lower than the traditional method), and the frost heave is reduced from 30 mm to 5 mm. This effectively avoids the risks of seepage damage and frost heave cracking, and improves the anti-sliding stability safety factor of the dam body by 15%, thus comprehensively ensuring the structural safety of the dam body.

[0019] An intelligent monitoring network integrating electromagnetic flowmeters (accuracy ±1%), piezometers (resolution 0.01kPa), and UAV infrared thermal imaging (crack resolution ≥0.1mm) provides an anomaly response time of <15 minutes, enabling real-time monitoring of seepage, stress, and crack status in the subgrade. Equipped with graphene-modified polyurethane repair materials (restoring bearing capacity to over 90% of design value within 72 hours) and self-healing microcapsules (healing cracks smaller than 0.3mm upon contact with water), it achieves rapid repair of subgrade damage, extending the subgrade's service life from the traditional 50 years to 100 years, significantly reducing later maintenance costs, and ensuring long-term stable operation of the dam. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the present invention; Figure 2 This is a schematic diagram of the SEM microstructure of the rockfill-polyurethane interface in this utility model. 1. Polyurethane elastic cushion layer; 11. Base layer; 12. Surface layer; 13. Shape memory alloy fiber; 2. Rockfill; 21. Permeable reinforcement layer; 3. Mortar cushion layer; 4. Anchor bar. Detailed Implementation

[0021] In the description of this disclosure, it should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0024] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments. Example

[0025] See Figure 1 and Figure 2 The present invention provides a polyurethane elastic cushion layer structure for a rockfill dam with a concrete panel, which is laid on the rockfill body 2 and is mainly used to support and protect the concrete panel 14.

[0026] The polyurethane elastic cushion layer 1 is the core functional layer, designed with gradient functional materials, and consists of a base layer 11 and a surface layer 12 from bottom to top. The base layer 11 is a high-elasticity polyurethane permeable concrete layer, and its designed thickness can be adjusted according to the dam height, typically 300-500 mm. The formulation of this base layer 11 controls its elastic modulus to 15 MPa, porosity to 22%, compressive strength ≥15 MPa, and permeability coefficient to 5 × 10⁻⁻⁻⁶. 4 The flow rate is cm / s, which can effectively achieve the reverse filtration function. Before pouring the base layer 11, 4% of the total mass of polyurethane prepolymer nano-SiO2 modifier is uniformly added to its mixture, and shape memory alloy fiber 13 with a pre-strain of 8% is implanted. The fiber length is 50mm and the distribution density is 20kg / m³.

[0027] The surface layer 12 is a self-healing polyurethane coating, formed by spraying onto the cured base layer 11, with a thickness controlled at 2.5 mm. This coating has an elongation at break of up to 600% and is pre-mixed with epoxy resin-based self-healing microcapsules with a particle size of 80 μm.

[0028] To further enhance the synergistic performance with the rockfill body 2, a silane coupling agent is first sprayed onto the compacted and leveled surface of the rockfill body 2 to form a penetration enhancement layer 21 with a penetration depth of not less than 5 mm. Subsequently, a 50 mm thick mortar cushion layer 3 is laid with a compressive strength of 28 MPa, and its surface roughness Ra reaches 60 μm through a scraping process.

[0029] The lower end of anchor bar 4 is anchored in the rockfill body, and the upper end passes vertically through the mortar cushion layer and extends into the base layer of the polyurethane cushion layer body, forming a firm mechanical interlock with the polyurethane material.

[0030] To control seepage, a trapezoidal drainage channel is installed every 2.5m within the base layer 11 of the polyurethane elastic cushion layer 1. The drainage channel is connected to the inlet of a siphon drainage system embedded inside the cushion layer. When the water pressure inside the cushion layer exceeds 0.1MPa, the siphon drainage system automatically activates, orderly discharging the seepage water outside the dam. Example

[0031] The difference between this embodiment and Embodiment 1 is that it integrates an intelligent monitoring system, forming an intelligent monitoring subgrade system.

[0032] During the pouring of the base layer 11 of the foundation body 1, distributed optical fiber sensors (using BOTDR technology) are simultaneously embedded. The optical fibers are arranged in a serpentine pattern, covering the entire foundation area, with a strain monitoring accuracy of ±1με. At the same time, piezometers (resolution 0.01kPa) are installed on the downstream side and at key points inside the foundation to monitor uplift pressure.

[0033] During the operation of the project, drones equipped with infrared thermal imaging lenses are used for regular inspections to detect cracks (0.1mm resolution) and voids on the surface of the subbase. The data is then verified and fused with data from distributed fiber optic sensors to achieve comprehensive and real-time perception of the health status of the entire subbase structure.

[0034] The working principle and process of this utility model: This cushion layer structure functions effectively through its unique gradient construction and material properties. When the dam body is subjected to water load and deforms, the shape memory alloy fibers are activated to generate restoring force, compensating for localized stress concentrations and preventing crack formation. If microcracks appear on the surface, self-healing microcapsules rupture to release repair fluid, healing them. After seepage water passes through the surface layer, it is filtered by the base layer, soil particles are blocked, and clean water is collected through diversion channels and finally discharged by a siphon drainage system, greatly reducing seepage pressure. Mechanical anchors and mortar cushion layers tightly integrate the flexible cushion layer with the rockfill body into a unified whole, coordinating deformation and significantly improving the overall stability of the dam body. Built-in sensors act like "nerve endings," continuously sensing the structural status and providing digital assurance for engineering safety.

[0035] It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A face-panel rockfill dam cushion layer structure, characterized in that, include: A polyurethane elastic padding layer, wherein the polyurethane elastic padding layer is composed of a base layer and a surface layer; The base layer is high-elasticity polyurethane permeable concrete with an elastic modulus of 10-20 MPa, a porosity of 20%-25%, a compressive strength ≥15 MPa, and a permeability coefficient of 1×10⁻³~1×10⁻ 4 cm / s; The surface layer is a self-healing polyurethane coating with a thickness of 2-3 mm and an elongation at break of ≥500%, capable of self-healing cracks smaller than 0.3 mm.

2. The panel rockfill dam cushion layer structure according to claim 1, characterized in that: Shape memory alloy fibers are embedded in the base layer, and the pre-strain of the shape memory alloy fibers is 5%-10%, which is used to automatically shrink to compensate for deformation when the strain of the pad layer exceeds 0.5%.

3. The panel rockfill dam cushion layer structure according to claim 1, characterized in that: An interface reinforcement layer is provided between the cushion layer and the rockfill body. The interface reinforcement layer is a silane coupling agent layer sprayed on the surface of the rockfill body, with a penetration depth ≥5mm and an interface bonding strength ≥1.5MPa.

4. The panel rockfill dam cushion layer structure according to claim 3, characterized in that: The bottom of the cushion layer is also provided with a mortar cushion layer with a thickness of 50mm, a compressive strength of ≥25MPa, an interface roughness Ra≥50μm, and is equipped with mechanical anchor bars with a spacing of 500mm.

5. The face-panel rockfill dam cushion layer structure according to claim 1, characterized in that: The polyurethane elastic pad has internal drainage channels with a spacing of 2-3m to control the seepage flow rate to be less than 0.1L / (m·d).

6. The face-panel rockfill dam cushion layer structure according to claim 1, characterized in that: It also includes a siphon drainage system, which automatically starts drainage when the water pressure inside the cushion layer exceeds 0.1 MPa.

7. A face-panel rockfill dam system, comprising a rockfill body and a cushion layer thereon, characterized in that: The padding layer is a polyurethane elastic padding layer as described in any one of claims 1-6.

8. An intelligent monitoring subbase system for rockfill dams with concrete panels, characterized in that: include: The polyurethane elastic padding layer as described in any one of claims 1-6; A distributed optical fiber sensor, wherein the distributed optical fiber sensor is embedded inside the polyurethane elastic pad layer; A piezometer, which is installed inside or downstream of the cushion structure, is used to monitor uplift pressure.

9. The intelligent monitoring subgrade system according to claim 8, characterized in that: It also includes an unmanned aerial vehicle (UAV) infrared thermal imaging inspection unit for detecting cracks and voids in the surface layer of the cushion layer from the outside.

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