CN222730484U - Head junction structure suitable for deep-coverage river reach diversion type power station - Google Patents

Abstract

The head junction structure is characterized by comprising a water inlet front pool formed by digging a deep-layer river bed, wherein the upstream and downstream bottom boundaries of the water inlet front pool are respectively communicated with a power station through a water diversion channel, the upstream and downstream boundaries of the water inlet front pool extend from the water inlet of the water diversion channel to two sides respectively, an upstream hidden dam and a downstream hidden dam are respectively arranged on the upstream and downstream sides of the water inlet front pool, the sections of the upstream hidden dam and the downstream hidden dam are trapezoidal, the heights of the dam tops of the two hidden dams are lower than the natural water level of a river and higher than the natural river bed line, an upstream anti-flushing section is arranged on the upstream side of the upstream hidden dam, a downstream sea-diffusing section is arranged on the downstream side of the downstream hidden dam, and the upstream anti-flushing section and the downstream sea-diffusing section are both transversely connected with two bank slopes. The utility model reduces the technical difficulty of basic treatment and flood discharge energy dissipation of the construction of the conventional head junction barrage of the water diversion type power station of the river reach with the deep coverage.

Description

Head junction structure suitable for deep-coverage river reach diversion type power station

Technical Field

The utility model belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a head junction structure suitable for a deep-coverage river reach diversion type power station.

Background

The water diversion type power station is characterized in that the height of the water choking of the head junction is usually not large, and the water diversion type power station mainly depends on the long water diversion channel to concentrate the fall of the river reach. In practical design, the head joints of the diversion type power station are distributed with soft covering layers with different thicknesses, the foundation bearing capacity and the anti-scouring capacity are low, the permeability is strong, more measures are needed to be adopted for treatment during building a dam, and particularly when the covering layers are deep, huge technical challenges are faced in the aspects of foundation treatment, seepage prevention, flood discharge and energy dissipation, and the like, and meanwhile the problems of complex construction, blocking of natural habitats of rivers, reservoir area inundation, large engineering investment and the like also exist.

Disclosure of utility model

The utility model aims to provide a head junction structure which is constructed on a water taking requirement of a power station, simplifies the design of a basic treatment and flood discharge energy dissipation building, and can reduce the influence of the power station development on ecological environment, reservoir area inundation and the like when the deep-coverage river reach is subjected to water diversion type power station development.

The head junction structure is characterized by comprising a water inlet front pool formed by digging a deep-thickness-coverage river bed, wherein the minimum working water depth S=cv_b of the water inlet front pool, c is an empirical coefficient, the value range is 0.55-0.73, the symmetric water inlet is small, and the lateral water inlet is large; v is the water flow speed of the gate section, d is the gate orifice height, the upstream and downstream bottom boundaries of the water inlet front pool are respectively communicated with the power station through the water diversion channel, the upstream and downstream boundaries of the water inlet front pool extend to two sides from the water inlet of the water diversion channel, the water inlet front pool Zuo An and the right bank boundary are arranged in a slope manner from the bottom of the water inlet front pool to two sides, the bottom elevation of the water inlet front pool = dead water level-minimum working water depth-the water inlet height of the water diversion channel-silt thickness, the upstream and downstream dark dams are respectively arranged on the upstream and downstream sides of the water inlet front pool, the cross sections of the upstream dark dam and the downstream dark dam are trapezoid, the dam top elevations of the two dark dams are lower than the natural water level of the river channel and higher than the natural river bed line, the upstream side of the upstream dark dam is provided with an upstream anti-flushing section, the downstream side of the downstream dark dam is arranged on the downstream side of the upstream dark dam, and the upstream and the downstream side anti-flushing section and the downstream side of the upstream dark dam are transversely connected with the two bank slopes.

Preferably, the bottom of the water inlet front pool is provided with a concrete seepage-proof plate with structural joints, and the spacing distance of the structural joints is 20m.

Further, the normal water level of the water inlet front pool is the natural water level corresponding to the average flow rate of the river course for years, and the dead water level is the natural water level corresponding to the average withering flow rate for years.

Further, the upstream anti-collision section and the downstream sea-diffusion section are composed of a gabion, reinforced concrete blocks or large-diameter rock mass paved along a natural river bed.

Preferably, the upstream dark dam and the downstream dark dam have an upstream-downstream slope ratio of 1:0.5.

The utility model has the beneficial effects that the deep and thick riverbed coverage layer is excavated to form the water inlet front pool, and the upstream hidden dam and the downstream hidden dam are built on the upstream side and the downstream side, so that the water taking requirement of a power station is met, the technical difficulties of basic treatment and flood discharge energy dissipation of the construction of the conventional head junction barrage are reduced, and the coordination problem of power station development, environmental protection and land protection is solved. The head junction scheme is economical and feasible in technology, has good applicability and application prospect when the diversion type power station is developed in the deep coverage river reach.

Drawings

FIG. 1 is a longitudinal sectional view of a head junction structure suitable for a deep-covered river reach water diversion power station

FIG. 2 is a cross-sectional view of a head-hinged structure suitable for a deep-covered river reach water-diversion power station

The water inflow front pool comprises a water inflow front pool body 1, an upstream hidden dam 2, a downstream hidden dam 3, an upstream anti-flushing section 4, a downstream sea-diffusing section 5, a concrete anti-seepage plate 6, a water guide channel 7, a deep covering layer 8, a water surface line 9, a natural river bed line 10 and an underlying bedrock 11.

Detailed Description

Embodiment 1A head junction structure suitable for a deep cover river reach diversion power station is provided, a pre-water inflow pool 1 formed by a river bed of a deep cover 8 is excavated, an upstream hidden dam 2 and a downstream hidden dam 3 are respectively arranged at the upstream and downstream of the pre-water inflow pool 1, an upstream anti-flushing section 4 is arranged at the upstream side of the upstream hidden dam, and a downstream sea diffuse section 5 is arranged at the downstream side of the downstream hidden dam.

In this embodiment, the thickness of the deep and thick river bed covering layer 8 is about 80m, the water inlet front pool 1 is formed by digging out part of the deep and thick river bed covering layer 8, the normal water level of the water inlet front pool 1 is 1735.82m, the natural water level corresponding to the average annual flow rate of the river channel is 1732.68m, and the dead water level is the natural water level corresponding to the average annual withered flow rate of the river channel. According to the power station design reference flow 423m ³/S and the section size 10m multiplied by 10mcm of the water inlet 7 of the water guide, calculating and obtaining the minimum working depth of the water inlet 7 of the water guide to be 12.43m by adopting a Gordon empirical formula (S=cv v b), wherein the bottom design silt thickness of the water inlet front pool 1 is 10m, and the bottom elevation of the water inlet front pool 1 is=dead water level-minimum working depth-the height of the water inlet 7 of the water guide to be the silt thickness= 1700.25m. The upstream and downstream bottom boundaries of the water inlet forerunner are respectively communicated with the power station through the water guide channel 7, and the upstream and downstream boundaries of the water inlet forerunner 1 extend from the water inlet of the water guide channel 7 to two sides by 50m respectively, so that stability of the upstream hidden dam 2 and the downstream hidden dam 3 is not affected during water taking, a reservoir capacity of about 50 ten thousand m ³ is formed, and certain reaction and regulation capacity are provided when the upstream water suddenly changes so as to ensure operation safety of the unit. The left dark and right bank boundaries of the water inlet front pool 1 are dug from the pool bottom of the water inlet front pool 1 to bank slopes at two sides, and unstable covering layers and weathered rock masses are removed to form stable side slopes.

The deep covering layer 8 has stronger permeability, in order to reduce the leakage of the water inflow front pool 1, a concrete impermeable plate 6 with the thickness of 0.8m is paved at the bottom of the water inflow front pool 1, and structural joints are arranged at 15m multiplied by 15m in the longitudinal and transverse directions so as to adapt to the uneven deformation of the deep covering layer 8.

The sections of the upstream hidden dam 2 and the downstream hidden dam 3 are trapezoidal, and a reinforced concrete structure is adopted, so that the width of the dam top is 5m. The dam top elevation of the upstream hidden dam 2 is 1735.32m, the dam top elevation of the downstream hidden dam 3 is 1732.38m below the normal water level of the pool 1 before water inflow, the dam top elevation is 0.3m below the dead water level of the pool 1 before water inflow, the dam top elevation is lower than the water surface line 9 and higher than the natural river bed line 10, water flows overtravel and does not block the natural habitat of the river, and the water choking heights of the upstream hidden dam 2 and the downstream hidden dam 3 are small, so that the inundation loss of a reservoir area is avoided. The upstream slope ratio of the upstream dark dam 2 to the downstream dark dam 3 is 1:0.5.

The dam foundation of the upstream hidden dam 2 and the downstream hidden dam 3 is not excavated to the underlying bedrock 11 and is located on the deep and thick covering layer 8, the deep and thick covering layer 8 of the dam foundation is rolled to improve compactness and bearing capacity, meanwhile, structural joints are arranged on the upstream hidden dam 2 and the downstream hidden dam 3 at intervals of 20m along the axial direction of the dam to adapt to the uneven deformation of the deep and thick covering layer 8, the deep and thick covering layer 8 of the dam foundation does not perform basic seepage prevention treatment, a certain seepage amount is allowed to exist, and the drainage of ecological flow of a river is met by combining dam top overflow.

The upstream hidden dam 2 and the downstream hidden dam 3 have extremely small water-choking height, no reservoir area is basically formed for inundation, the flood coming in the temporary river channel is more different from the natural flood-running state, the flushing of the river bed caused by concentrated drop increase due to the construction of the upstream hidden dam 2 and the downstream hidden dam 3 is not generated, and no special flood discharging and energy dissipating facilities are arranged.

The upstream scour protection section 4 and the downstream sea diffuse section 5 are respectively positioned on the upstream side of the upstream hidden dam 2 and the downstream side of the downstream hidden dam 3, the lengths of the parallel river sections are respectively 50m and 80m, and the transverse river direction is connected with the bank slopes of the two banks. The upstream scour prevention section 4 and the downstream sea diffusion section 5 are paved with stones with the block diameters of more than 1.5m along the natural river bed, so that sufficient scour resistance is ensured when flood comes, the river bed stability is ensured, and a local dangerous beach and drop landscape is created.

Compared with the traditional water diversion type power station head junction dam-building water intake mode, the head junction device is suitable for the head junction of the deep-thickness coverage river reach water diversion type power station, the head junction device sacrifices the available water head by about 20m, compared with the 300 m-level water head utilization reduction proportion of the water diversion type power station, but greatly simplifies the design of the head junction foundation treatment and flood discharge energy dissipation building on the deep-thickness coverage layer 8, protects the natural habitat of river channels, overcomes the contradiction between dam building water accumulation, environmental protection and land protection, and can also create a local dangerous beach drop landscape.

In summary, the present utility model effectively solves the various problems in the prior art and has high industrial utility value.

Claims (5)

1. A head junction structure suitable for a deep-thick-layer river reach diversion power station is characterized by comprising a water inlet front pool formed by digging a deep-thick-layer river reach, wherein c is an empirical coefficient, the minimum working depth S=cv is calculated, the value range is 0.55-0.73, a small value is obtained during symmetric water inlet, a large value is obtained during lateral water inlet, v is the water flow speed of a gate section, d is the gate orifice height, the upstream and downstream bottom boundaries of the water inlet front pool are respectively communicated with the power station through a diversion channel, the upstream and downstream boundaries of the water inlet front pool extend to two sides from a water inlet of the diversion channel respectively, the water inlet front pool Zuo An and the right bank boundary are arranged in a manner of being inclined from the bottom of the water inlet front pool to two sides of the bank, the bottom elevation=dead water level-minimum working depth-the water inlet height-silt thickness of the water inlet front pool, an upstream hidden dam and a downstream hidden dam are respectively arranged on the upstream side and the downstream side of the water inlet front pool, the upstream and downstream dam are respectively arranged on the downstream side of the water inlet front pool, the upstream and downstream side of the hidden dam and downstream side of the water inlet is arranged on the two sides of the hidden dam, the two side of the hidden dam sections are arranged on the side of the water level and the side of the hidden dam, and the water level is arranged on the side of the two side of the natural river reach, and the side, and the hidden dam is arranged on the side and the side, and the side is flush between the two side and the side front side is flush against the side on the side front side.

2. The head junction structure suitable for a deep-coverage river reach diversion power station as claimed in claim 1, wherein the bottom of the water inlet front pool is provided with a concrete impermeable plate with structural joints, and the spacing distance of the structural joints is 20m.

3. The head junction structure for a deep-coverage river reach diversion power station as claimed in claim 1, wherein the normal water level of the water inlet front pool is a natural water level corresponding to the average flow rate of a river channel for years, and the dead water level is a natural water level corresponding to the average withered flow rate for years.

4. A head junction structure suitable for use in a deep covered river reach diversion power station as defined in claim 1, wherein said upstream and downstream ocean-going sections are comprised of gabions, reinforced concrete blocks or large diameter rock mass laid along the natural river bed.

5. The head junction structure for a deep-covered river reach diversion power station as claimed in claim 1, wherein the upstream hidden dam and the downstream hidden dam have an upstream-downstream slope ratio of 1:0.5.