Layered compaction and staggered filling construction method for heightening and expanding earth and rockfill dam

Abstract

The invention provides a layered compaction and staggered filling construction method for heightening and expanding an earth and rockfill dam. The layered compaction and staggered filling construction method comprises the following steps that the filling height of a part to be heightened and expanded is divided into a plurality of horizontal layers; filling each horizontal layer in a staggered filling manner; compacting is conducted after filling of each horizontal layer is completed, and the number of times of compacting is determined according to the properties of earth and rock materials and the compacting result of the test section; the step of filling in the staggered filling mode comprises the steps that filling material boundaries of follow-up horizontal layers are determined in sequence, the filling material boundaries of every two adjacent horizontal layers are staggered, and multi-horizontal-layer filling is conducted in sequence. By means of layered filling and staggered filling, the shear strength of the dam body is effectively improved, stress concentration in the dam body is reduced, and the overall stability of the dam body is improved.

Description

Technical Field

[0001] This invention relates to the field of earth-rock dam heightening and expansion technology, specifically to a layered compaction and staggered filling construction method for earth-rock dam heightening and expansion. Background Technology

[0002] Earth-rock dams, as a common hydraulic engineering structure, are widely used in reservoirs, flood control, and irrigation. With socio-economic development and increasing water resource demands, many existing earth-rock dams need to be heightened and expanded to improve their water storage capacity, flood control standards, and comprehensive utilization benefits. However, the heightening and expansion of earth-rock dams faces numerous technical challenges, particularly in construction techniques and dam stability. Traditional earth-rock dam heightening and expansion construction typically employs layered filling and compaction methods. While simple, this method is prone to uneven compaction at higher dam heights. For example, areas near the dam slope may experience insufficient compaction due to the difficulty of reaching compaction equipment, thus affecting the overall stability of the dam. Traditional layered filling methods often fail to consider the bonding between the old and new dam sections, leading to stress concentration at the junction. Traditional construction methods cannot effectively disperse stress, resulting in insufficient shear strength at the junction and a tendency for localized sliding or cracking. Summary of the Invention

[0003] This application provides a layered compaction and staggered filling construction method for raising and expanding earth-rock dams. Through layered filling and staggered filling, the shear strength of the dam body is effectively increased, stress concentration within the dam body is reduced, and the overall stability of the dam body is improved. The objective of this invention is achieved as follows: A method for layered compaction and staggered filling construction in the heightening and expansion of earth-rock dams includes the following steps: The filling height of the section to be heightened and expanded is divided into several horizontal layers; Each of the aforementioned horizontal layers is filled using a staggered filling method; After each horizontal layer is filled, compaction is carried out. The number of compaction passes is determined based on the properties of the soil and rock materials and the compaction results of the test section. The steps for filling using the staggered filling method include: After the first level of filling is completed, the boundary of the filling material is determined. The boundary of the filling material of the second horizontal layer is offset by a preset distance to the first side relative to the corresponding boundary of the filling material of the first horizontal layer, and the filling of the second horizontal layer is carried out. After the second level layer is filled, the boundary of the filling material of the third level layer is determined to be offset by a preset distance to the second side relative to the corresponding boundary of the filling material of the second level layer, and the filling of the third level layer is carried out. Repeat the above steps to determine the boundaries of the filling materials for each subsequent horizontal layer in turn, so that the boundaries of the filling materials for two adjacent horizontal layers are staggered, and carry out the filling of multiple horizontal layers in turn.

[0004] The offset distance between the boundaries of the filling material between two adjacent horizontal layers is equal according to a preset distance.

[0005] The preset offset distance between the boundaries of the filling material between two adjacent horizontal layers is 0.5m-1.0m.

[0006] The compaction process after each horizontal layer of filling is completed includes the following steps: A heavy vibratory roller was selected as the compaction equipment, and the roller's travel speed was controlled between 2 km / h and 4 km / h. The number of compaction passes was determined based on the properties of the soil and rock materials and the compaction results of the test section.

[0007] After each horizontal layer is compacted and before the next horizontal layer is filled, settlement observation points and displacement observation points are set on the top surface of the current horizontal layer.

[0008] The settlement observation points are set at intervals of 20m-30m along the dam axis, and the displacement observation points are set at intervals of 10m-20m along the dam axis.

[0009] The settlement observation points are spaced 25m apart, and the displacement observation points are spaced 15m apart.

[0010] During the compaction process of each horizontal layer, the compaction degree is tested using the ring cutter method or the sand cone method to ensure that the compaction degree meets the construction requirements. The compaction degree is tested at a frequency of 1 point per 100m², and at least 3 points are tested for each layer.

[0011] The acceptance standard for the compaction degree is greater than or equal to 95% of the design value.

[0012] During construction monitoring, drones or satellite remote sensing are used to assist in monitoring the overall deformation of the dam body. Combined with settlement and displacement observation data, the stability of the dam body is comprehensively assessed.

[0013] The present invention has the following beneficial effects: 1. By using layered and staggered filling methods, the shear strength of the dam body is effectively increased, stress concentration inside the dam body is reduced, and the overall stability of the dam body is improved. 2. By strictly controlling compaction parameters and compaction degree testing, the compaction quality of the dam body was ensured; 3. The construction method of the present invention is simple and easy to implement, with high construction efficiency. It is applicable to various types of earth-rock dam heightening and expansion projects and has broad application prospects. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a schematic diagram of the staggered filling process of the present invention; Figure 3 This is a partial sectional view of the expanded earth-rock dam involved in this invention; In the diagram: 1. Old earth-rock dam; 2. Expansion section of earth-rock dam; 21. Boundary of fill material in the first horizontal layer; 22. Boundary of fill material in the second horizontal layer; 23. Boundary of fill material in the first horizontal layer. Detailed Implementation

[0016] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0017] To achieve the above-mentioned technical features, the objective of this invention is as follows: See appendix Figure 1-3 A method for layered compaction and staggered filling construction for raising and expanding earth-rock dams includes the following steps: The filling height of the section to be heightened and expanded is divided into several horizontal layers; The staggered filling method is used to fill each horizontal layer; After each horizontal layer is filled, compaction is carried out. The number of compaction passes is determined based on the properties of the soil and rock materials and the compaction results of the test section. The steps for filling using the staggered filling method include: After the first level of filling is completed, the boundary of the filling material is determined. The boundary of the filling material of the second horizontal layer is offset by a preset distance to the first side relative to the corresponding boundary of the filling material of the first horizontal layer, and the filling of the second horizontal layer is carried out. After the second level layer is filled, the boundary of the filling material of the third level layer is determined to be offset by a preset distance to the second side relative to the corresponding boundary of the filling material of the second level layer, and the filling of the third level layer is carried out. Repeat the above steps to determine the boundaries of the filling materials for each subsequent horizontal layer in turn, so that the boundaries of the filling materials for two adjacent horizontal layers are staggered, and carry out the filling of multiple horizontal layers in turn.

[0018] In existing construction techniques, stress concentration easily occurs at the junction of the old and new dam bodies. Traditional construction methods cannot effectively disperse this stress, leading to insufficient shear strength at the junction and making it prone to local sliding or cracking. This invention first determines the boundaries of the filling material for each subsequent horizontal layer in sequence, staggering the boundaries of adjacent horizontal layers, and then sequentially constructs multiple horizontal layers. (See...) Figure 3 This constitutes a construction method of layered filling and staggered filling, which effectively increases the shear strength of the dam body, reduces stress concentration inside the dam body, and improves the overall stability of the dam body.

[0019] Furthermore, the offset distance between the boundaries of the filling material between two adjacent horizontal layers is preset to be equal, in order to facilitate a more uniform distribution of stress.

[0020] Furthermore, the preset offset distance between the boundaries of the filling materials between two adjacent horizontal layers is 0.5m-1.0m.

[0021] Furthermore, after each horizontal layer of filling is completed, a compaction process is carried out, including the following steps: Furthermore, a heavy vibratory roller was selected as the compaction equipment, and the roller's travel speed was controlled between 2 km / h and 4 km / h. Based on the properties of the soil and rock materials and the compaction results of the test section, the number of compaction passes was determined. According to the determined number of compaction passes, compaction operations were carried out on each horizontal layer. During the construction process, the surface flatness of the fill layer was controlled to ensure that the height difference of each fill surface does not exceed ±2 cm, so as to ensure the uniform compaction effect of the compaction equipment.

[0022] After each horizontal layer is compacted and before the next horizontal layer is filled, settlement observation points and displacement observation points are set on the top surface of the current horizontal layer.

[0023] The settlement monitoring points are set at intervals of 20m-30m along the dam axis, and the displacement monitoring points are set at intervals of 10m-20m along the dam axis. The monitoring data are collected and analyzed in real time through an automatic monitoring system. When the settlement rate exceeds 5mm / d or the displacement rate exceeds 2mm / d, construction is immediately suspended and corresponding reinforcement measures are taken.

[0024] Furthermore, the settlement observation points are spaced 25m apart, and the displacement observation points are spaced 15m apart, to improve monitoring accuracy and promptly detect minor deformations of the dam body. Optimizing the layout of monitoring points reduces monitoring costs and improves monitoring efficiency.

[0025] During the compaction process of each horizontal layer, the compaction degree is tested using the ring cutter method or the sand cone method to ensure that the compaction degree meets the construction requirements. The compaction degree is tested at a frequency of 1 point per 100m², and at least 3 points are tested for each layer. If the test results do not meet the design requirements, additional compaction is carried out until the compaction degree is qualified.

[0026] The acceptance standard for compaction is greater than or equal to 95% of the design value, to ensure the compaction quality of the dam body and improve the long-term stability and durability of the dam body; providing clear acceptance standards facilitates construction quality control and acceptance.

[0027] During construction monitoring, drones or satellite remote sensing are used to assist in monitoring the overall deformation of the dam body. Combined with settlement and displacement observation data, the stability of the dam body is comprehensively assessed. After construction is completed, the quality of the heightened and expanded dam body is inspected, including compaction, settlement, displacement, and dam appearance.

[0028] An automatic monitoring system refers to an integrated set of monitoring equipment and data acquisition systems used to monitor various physical parameters of the dam body in real time during construction and operation, such as settlement, displacement, stress, and strain. This system can provide high-precision, high-frequency data, helping construction personnel to understand the dynamic changes of the dam body in a timely manner, thereby taking corresponding measures to ensure construction safety and dam stability.

[0029] The automatic monitoring system includes: Settlement sensors: These typically employ high-precision levels or hydrostatic levels to measure the vertical settlement at different locations within the dam body. These sensors can monitor in real time whether uneven settlement occurs during the dam's construction.

[0030] Displacement sensors: These include total stations, GPS devices, or displacement gauges, used to measure the horizontal displacement of the dam body. These sensors can monitor whether horizontal deformation occurs in the dam body during construction and operation.

[0031] Stress and strain sensors, such as strain gauges and pressure sensors, are used to measure the stress and strain conditions inside the dam body. This data helps analyze the stress state of the dam body and ensures its stability during construction and operation.

[0032] Seepage pressure sensor: Although this invention does not involve the direction of seepage, in some integrated monitoring systems, seepage pressure sensors can be used to monitor the water pressure inside the dam body in order to assess the impact of seepage on the stability of the dam body.

[0033] Data acquisition unit: Used to collect data transmitted from sensors, and to perform preliminary processing and storage. These acquisition units typically have high-precision and high-frequency data acquisition capabilities, and can record changes in various parameters of the dam body in real time.

[0034] Data transmission module: Transmits the collected data to the central monitoring system via wired or wireless communication technology. Wireless transmission is particularly suitable for scenarios with complex construction environments and difficult wiring.

[0035] Monitoring software: Used to display and analyze data collected by sensors in real time. This software usually has data visualization functions, such as real-time charts and graphs, to help construction personnel intuitively understand the dynamic changes of the dam body.

[0036] Data analysis module: This module analyzes the collected data using built-in algorithms to determine the stability of the dam. For example, when the settlement rate or displacement rate exceeds a set threshold, the system will automatically issue an alarm to remind construction personnel to take appropriate measures.

[0037] Historical data storage and backtracking: The system stores the collected data long-term, facilitating analysis and evaluation of long-term changes in the dam body by construction personnel. The historical data backtracking function helps construction personnel better understand the dynamic behavior of the dam body and optimize construction plans.

[0038] Real-time alarm function: When the monitored data exceeds the preset safety threshold, the system will immediately issue an audible and visual alarm or SMS notification to remind construction personnel to take timely measures. For example, when the settlement rate of the dam exceeds 5 mm / d or the displacement rate exceeds 2 mm / d, the system will trigger an alarm.

[0039] Early warning function: The system can perform trend analysis based on historical and real-time data, predict potential instability in the dam body in advance, and issue early warning information to help construction personnel take preventive measures in advance.

[0040] In the construction of earth-rock dam heightening and expansion projects, automatic monitoring systems are mainly used in the following aspects: During the filling and compaction process, the settlement and displacement of the dam body are monitored in real time to ensure the stability of the dam body during construction. After the dam body construction is completed, an automatic monitoring system is used for long-term monitoring to assess the stability of the dam body during operation, promptly identify potential problems, and take measures. By introducing an automatic monitoring system, the construction safety and dam body stability of earth-rock dam heightening and expansion projects can be significantly improved, making it an indispensable technical means in modern water conservancy projects.

[0041] Example: Taking the heightening and expansion project of an earth-rock dam in a reservoir as an example, the original dam height was 30m, and it was planned to be increased by 5m. The construction process is as follows: Construction preparation: Conduct a detailed geological survey and structural assessment of the original earth-rock dam to determine the scope and height of the expansion project, which is 5 meters. Clear debris and loose soil and rocks from the dam crest and both sides to ensure a flat construction surface.

[0042] Layered filling: The filling height of the expanded section is divided into 5 horizontal layers, each with a height of 1.0m.

[0043] A staggered filling method is adopted, in which the filling boundaries of adjacent horizontal layers are staggered by a distance of 0.5m. Specifically, after the first horizontal layer is filled, the filling boundary of the second horizontal layer is shifted to one side by 0.5m, the filling boundary of the third horizontal layer is shifted to the other side by 0.5m, and so on.

[0044] Horizontal layered compaction: After each horizontal layer of filling was completed, a heavy vibratory roller was used for compaction. During compaction, the roller's travel speed was controlled at 3 km / h, and the vibration frequency was controlled at 40 Hz. The number of compaction passes was determined to be 8 passes based on the properties of the soil and rock materials and the compaction results of the test section.

[0045] During the compaction process, the compaction degree is tested using the ring cutter method to ensure that the compaction degree meets the design requirements. The compaction degree is tested at a frequency of one point per 100m², and at least three points are tested for each layer. If the compaction degree does not meet the design requirements, additional compaction is performed until the compaction degree is qualified.

[0046] Construction Monitoring: During construction, settlement and displacement monitoring points are set up to monitor the settlement and displacement of the dam body in real time. The spacing between settlement monitoring points is 25m, and the spacing between displacement monitoring points is 15m. The monitoring data is collected and analyzed using an automatic monitoring system. When the settlement rate exceeds 5mm / d or the displacement rate exceeds 2mm / d, construction is immediately suspended, and corresponding reinforcement measures are taken.

[0047] Construction Acceptance: After construction is completed, the quality of the heightened and expanded dam body will be inspected. The inspection will include compaction, settlement, displacement, and dam appearance. The compaction standard is no less than 95% of the design value. Settlement and displacement should meet design requirements, and the dam body should have a smooth appearance without obvious cracks or deformation.

Claims

1. A layered compaction and staggered filling construction method for earth and rockfill dam heightening expansion, characterized in that, The method comprises the following steps: dividing the filling height of the to-be-added high extension part into a plurality of horizontal layers; filling each horizontal layer by staggered filling; compacting each horizontal layer after filling is completed, and the number of compaction passes is determined according to the properties of the earth and stone materials and the compaction result of the test section; the step of filling by staggered filling comprises: after the first horizontal layer is filled, the filling material boundary thereof is measured; the filling material boundary of the second horizontal layer is determined to be offset by a preset distance to the first side relative to the corresponding filling material boundary of the first horizontal layer, and the second horizontal layer is filled; after the second horizontal layer is filled, the filling material boundary of the third horizontal layer is determined to be offset by a preset distance to the second side relative to the corresponding filling material boundary of the second horizontal layer, and the third horizontal layer is filled; the above steps are repeated to determine the filling material boundary of each subsequent horizontal layer in turn, so that the filling material boundaries of adjacent two horizontal layers are staggered, and the filling of multiple horizontal layers is sequentially performed.

2. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 1, characterized in that: The offset preset distance between the filling material boundaries of adjacent two horizontal layers is equal.

3. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 2, characterized in that: The offset preset distance between the filling material boundaries of adjacent two horizontal layers is 0.5m-1.0m.

4. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 1, characterized in that, The process of compacting each horizontal layer after filling is completed comprises the following steps: a heavy vibratory roller is selected as the compaction equipment, the driving speed of the roller is controlled to be between 2km / h and 4km / h, and the number of compaction passes is determined according to the properties of the earth and stone materials and the compaction result of the test section.

5. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 1, characterized in that: After each horizontal layer is compacted, a settlement observation point and a displacement observation point are arranged on the top surface of the current horizontal layer before filling of the next horizontal layer.

6. The layered compaction and staggered filling construction method for the heightening and expansion of an earth-rock dam according to claim 5, characterized in that: The arrangement interval of the settlement observation points along the dam axis direction is 20m-30m, and the arrangement interval of the displacement observation points along the dam axis direction is 10m-20m.

7. The layered compaction and staggered filling construction method for the heightening and expansion of earth-rock dams according to claim 6, characterized in that: The arrangement interval of the settlement observation points is 25m, and the arrangement interval of the displacement observation points is 15m.

8. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 1, characterized in that: During the compaction of each horizontal layer, the compaction degree is detected by a cutting ring method or a sand pouring method to ensure that the compaction degree reaches the construction requirement, the detection frequency of the compaction degree is 1 point per 100m², and at least 3 points per layer are detected.

9. The layered compaction and staggered filling construction method for the heightening and expansion of an earth-rock dam according to claim 8, characterized in that: The acceptance standard of the compaction degree is greater than or equal to 95% of the design value.

10. The layered compaction and staggered filling construction method for heightening and expansion of earth-rock dams according to claim 1, characterized in that: During the construction monitoring, the overall deformation of the dam body is monitored by using a drone or satellite remote sensing, and the stability of the dam body is comprehensively evaluated in combination with the settlement and displacement observation data.

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