CN207525718U - A kind of flood discharging tunnel gentle slope and abrupt slope connection structure - Google Patents

Abstract

The utility model relates to a connection structure between a gentle slope and a steep slope of a flood discharge tunnel, which comprises a gentle slope section located upstream, a steep slope section located downstream, and an aeration structure connected between the gentle slope section and the steep slope section; the bottom plate of the gentle slope section, Both the bottom plate of the steep slope section and the bottom plate of the aeration structure are plane, wherein the bottom plate of the aeration structure is arranged horizontally. The connection structure described in the utility model greatly simplifies the difficulty of structural design, reduces the workload of design and research, and saves engineering costs at the same time.

Description

A connection structure between gentle slope and steep slope of flood discharge tunnel

technical field

The utility model relates to the field of shape design of flood discharge tunnels of water conservancy and hydropower projects, in particular to a connection structure between gentle slopes and steep slopes of flood discharge tunnels.

Background technique

With the construction of large-scale water conservancy and hydropower projects in Southwest my country, limited by project layout conditions, and at the same time to increase the safety and flexibility of flood discharge, many projects have flood discharge tunnels arranged in the bank slope of the dam site area to participate in flood discharge. The design of the flood discharge tunnel is It is one of the important factors affecting flood discharge safety and engineering safety.

The design of the transition section and connection section of the spillway tunnel is the key point of the shape design of the spillway tunnel. When the flood tunnel is limited by the topographic conditions, when the "dragon tail" scheme is adopted, there is a transitional connection section between the upper gentle slope section (including the horizontal floor) and the lower steep slope section. For eclipse, this section is required to be connected with a parabolic bottom plate, which is generally called "vortex odd section" or "parabolic section". The disadvantage of this connection method is that the design of the parabolic equation is more difficult, and this body type generally needs to customize a special formwork during the on-site construction process, which is difficult to construct and requires high construction accuracy.

When designing the shape of the spillway tunnel, the setting of the aerated structure is usually also considered. The aeration structure is used to replenish the water flow in the flood discharge tunnel, which can effectively reduce the cavitation of the water flow caused by the turbulence of the high-speed water flow, reduce the cavitation damage caused to the overflow surface of the flood discharge tunnel, and achieve a smooth flow state and sufficient aeration. Effect. Usually, the aerated structure will be installed in the steep slope section of the spillway with a large flow velocity according to the needs, and it is generally located downstream of the "vortex section" of the connecting section. Due to the complex structure of the "vortex section" and the aerated structure in the flood discharge tunnel, the design is difficult. In the actual implementation process, special templates need to be customized. The construction is difficult and the construction accuracy is high, which consumes a lot of manpower and resources. Financial investment.

Based on the above situation, it is urgent to design a new type of gentle slope and steep slope connection structure of the spillway tunnel that can solve the above problems.

Utility model content

The purpose of the utility model is to overcome the difficulty of construction of the parabolic connection between the gentle slope section and the steep slope section of the flood discharge tunnel and the high cost of the overall project of the flood discharge tunnel, and provide a new type of connection structure between the gentle slope and the steep slope of the flood discharge tunnel. The aeration structure is set between the sections, and the parabolic section of the flood discharge tunnel is canceled, thereby reducing the difficulty of the project and saving engineering investment. At the same time, the setting of the aeration structure reduces the cavitation damage of the high-speed water flow and ensures the safe operation of the flood discharge tunnel.

In order to achieve the above object, the gentle slope and steep slope connection structure of the flood discharge tunnel described in the utility model includes a gentle slope section located upstream, a steep slope section located downstream, and an aeration structure connected between the gentle slope section and the steep slope section; The bottom plate of the gentle slope section, the bottom plate of the steep slope section and the bottom plate of the aeration structure are all planes, wherein the bottom plate of the aeration structure is arranged horizontally.

Further, the aeration structure includes a vertical drop sill, through holes arranged at both ends of the vertical drop sill and at the bottom of the two side walls, ventilation pipes arranged in the two side walls, and arranged in the corresponding top plates of the two side walls. An air inlet connected to the atmosphere; the lower ends of the two ventilation pipes are respectively connected to the corresponding through holes, and the upper ends of the two ventilation pipes are respectively connected to the corresponding air inlets.

Further, the through hole is a right-angled trapezoidal quadrangular prism configuration; wherein, the left and right end faces are right-angled trapezoidal, the bottom side is equal in width and coplanar with the bottom plate of the vertical drop, and the upstream side and the downstream side are located on both sides of the bottom side. and perpendicular to the bottom side, the height of the upstream side is higher than that of the downstream side, and the top slope is provided with an air vent communicating with the lower end of the air pipe.

Further, the ratio of the height of the upstream side to the height of the downstream side is 1.5:1-5:1.

Further, the ventilation pipe is in the shape of a cylinder or a regular prism.

Further, the gentle slope section of the spillway tunnel, the steep slope section of the spillway tunnel and the aerated structure are constructed by integral pouring.

The beneficial effects of the utility model are:

The flood discharge tunnel described in the utility model uses an air-entrained structure instead of a parabola as the connection structure between the gentle slope section and the steep slope section. Design study workload while saving engineering costs. The base plates of the gentle slope section, the steep slope section and the aerated structure are all flat, and the design is less difficult. During the on-site construction process, there is no need to customize a special curved surface formwork, and the general shaped formwork can be used to meet the pouring needs of the structural concrete without additional investment. The manpower and construction costs are relatively simple, and the bottom plate is a flat structure, and the drawing form construction method can be used, and the accuracy requirements are relatively easy to meet. The flood discharge tunnel of the utility model can be constructed by integral pouring, the construction time is short, and the construction cost can be further saved.

The through hole of the aeration structure of the flood discharge tunnel described in the utility model adopts a right-angled trapezoidal quadrangular prism configuration, which can avoid the blocking effect of the flood discharge tongue on the through hole, so as to ensure the ventilation volume and ventilation effect, and effectively reduce the high-speed water flow on the concrete surface of the flood discharge tunnel. cavitation damage to ensure the normal operation of the spillway tunnel as a whole.

Through verification, using the aeration structure described in the utility model as the connection structure between the gentle slope section and the steep slope section, its hydraulic conditions are basically equivalent to the connection structure of the parabolic transition section, the water flow is smooth, the flow state is good, and there is no negative impact on the flow surface. At the same time, through the aeration effect of the aeration structure, the cavitation damage of the high-speed water flow in the steep slope section is effectively avoided, and the operation safety of the spillway tunnel is guaranteed.

Description of drawings

Fig. 1 is the longitudinal sectional view of the gentle slope and the steep slope connection structure of the flood discharge tunnel described in the utility model;

Fig. 2 is the plane view of the connection structure between the gentle slope and the steep slope of the flood discharge tunnel described in the utility model;

Fig. 3 is a structural schematic diagram of the connection structure between the gentle slope and the steep slope of the flood discharge tunnel described in the present invention;

FIG. 4 is a schematic structural diagram of the through hole described in the present invention.

In the picture:

Gentle slope section 1; steep slope section 2; aeration structure 3; vertical drop sill 3.1; through hole 3.2; ventilation pipe 3.3; air inlet 3.4; end face 3.2.1; bottom side 3.2.2; upstream side 3.2.3; downstream side 3.2 .4; top slope 3.2.5; vent 3.2.5.1; side wall 4; roof 5;

Detailed ways

The implementation of the utility model will be described in detail below in conjunction with the accompanying drawings, but they do not constitute a limitation of the utility model, and are only examples. Simultaneously, the utility model is described in further detail through and specific implementation.

The "integral pouring" mentioned in the utility model refers to that the 3 parts of the aerated structure and the adjacent gentle slope section 1 of the spillway tunnel and the steep slope section 2 of the spillway tunnel are used for integral concrete pouring construction with a general planar formwork.

Taking a hydropower station project as an example, three spillway tunnels are set up on the left bank, all of which use aerated structures as the connection structure between the gentle slope section and the steep slope section.

As shown in Fig. 1 and Fig. 2, the connection structure between the gentle slope and the steep slope of the spillway includes an upstream gentle slope section 1 and a downstream steep slope section 2, and an aeration structure 3 is arranged between the gentle slope section 1 and the steep slope section 2. The bottom plates of the gentle slope section 1 and the steep slope section 2 are both inclined planes and the front end is higher than the rear end. The bottom plate of the aeration structure 3 is arranged horizontally.

As shown in Figures 1-4, the aeration sill of the aeration structure 3 is in the form of a vertical drop 3.1, and the two ends of the vertical drop 3.1 are provided with through holes 3.2, and the two through holes 3.2 are respectively Located at the bottom of both side walls 4. The through hole 3.2 is a right-angled trapezoidal quadrangular prism configuration; wherein, the left and right two end faces 3.2.1 are right-angled trapezoidal, the bottom side 3.2.2 is equal in width and coplanar with the bottom plate of the vertical drop 3.1, and the upstream side 3.2. 3 and the downstream side 3.2.4 are located at both ends of the bottom side 3.2.2 and are perpendicular to the bottom side 3.2.2, the height of the upstream side 3.2.3 is higher than the height of the downstream side 3.2.4, in the three flood discharges of this embodiment In the hole, the ratio of the height of the upstream side 3.2.3 to the height of the downstream side 3.2.4 is 1.5:1. Air vents are provided on the top slope 3.2.5 connected to the upstream side 3.2.3 and the downstream side 3.2.4 respectively on both sides

3.2.5.1, the vent 3.2.5.1 communicates with the lower end of the vent pipe 3.2.3.

The aeration structure 3 also includes a ventilation pipe 3.3 arranged in the two side walls 4 and an air inlet 3.4 arranged in the corresponding top plate 5 of the two side walls 4 . The two ventilation pipes 3.3 adopt a cylindrical configuration, the lower ends of which are respectively connected to the corresponding through holes 3.2, and the upper ends are respectively connected to the corresponding air inlets 3.4, and the air inlets 3.4 communicate with the atmosphere.

The construction side of the present embodiment spillway is as follows:

①Construction of the gentle slope section 1 of the flood discharge tunnel and the steep slope section 2 of the flood discharge tunnel shall be carried out by conventional construction methods (construction of steel formwork trolley, construction of shaped formwork, etc.);

②Using general planar formwork for integral concrete pouring construction at the position of aerated structure 3 and the adjacent gentle slope section 1 and steep slope section 2 of the spillway tunnel (the bottom plate can also be constructed by drawing formwork);

③ Wipe the surface of the spillway tunnel structure to meet the structural accuracy requirements.

In this embodiment, since the aerated structure 3 is used to replace the conventional parabolic transition section connection method, the difficulty of structural design and construction is greatly simplified, the construction process is simplified, and the normal operation safety of the flood tunnel is improved, regardless of the construction period The indirect economic benefits in advance save about 102,000 yuan in project direct investment, see Table 1 for details.

Table 1 Summary table of construction project cost savings comparison

In this embodiment, the air-entrained structure of the present invention is used as the connection structure between the gentle slope section and the steep slope section, and its hydraulic conditions are basically equivalent to the connection structure of the parabolic transition section. At the same time, through the aeration effect of the aeration structure, the cavitation damage of the high-speed water flow in the steep slope section is effectively avoided, and the operation safety of the spillway tunnel is guaranteed. The model test results are shown in Table 2.

Table 2 Comparison list of model test results

Claims (6)

1. a kind of flood discharging tunnel gentle slope and abrupt slope connection structure, it is characterised in that：Under being located at the gentle slope section (1) of upstream, being located at The steep slope section (2) of trip and the aeration structure (3) being connected between gentle slope section (1) and steep slope section (2)；The gentle slope section (1) The bottom plate of bottom plate, the bottom plate of steep slope section (2) and aeration structure (3) is plane, and the bottom plate of wherein aeration structure (3) is set for level It puts.

2. flood discharging tunnel gentle slope according to claim 1 and abrupt slope connection structure, it is characterised in that：The aeration structure (3) Including vertically falling bank (3.1), being arranged on the vertical through-hole (3.2) for falling bank (3.1) both ends and being located at both walls (4) bottom, setting It snorkel (3.3) in both walls (4) and is arranged in the corresponding top plate (5) of both walls (4) and in the air inlet of atmosphere Mouth (3.4)；The lower end of two snorkels (3.3) connects respectively with corresponding through-hole (3.2), two snorkels (3.3) upper end connects respectively with corresponding air inlet (3.4).

3. flood discharging tunnel gentle slope according to claim 2 and abrupt slope connection structure, it is characterised in that：The through-hole (3.2) is Right-angled trapezium tetragonous column configuration；Wherein, left and right two end faces (3.2.1) are right-angled trapezium, and bottom side (3.2.2) falls with vertical The bottom plate of bank (3.1) is wide and coplanar, and upstream side (3.2.3) and downstream side (3.2.4) are positioned at bottom side (3.2.2) two It holds and perpendicular to bottom side (3.2.2), the height of the upstream side (3.2.3) is higher than the height of downstream side (3.2.4), Top side inclined-plane (3.2.5) is equipped with the blow vent (3.2.5.1) connected with snorkel (3.3) lower end.

4. flood discharging tunnel gentle slope according to claim 3 and abrupt slope connection structure, it is characterised in that：The upstream side The height of (3.2.3) is 1.5 with the height ratio of downstream side (3.2.4):1-5:1.

5. flood discharging tunnel gentle slope according to claim 2 and abrupt slope connection structure, it is characterised in that：The snorkel (3.3) For cylinder or regular prism configuration.

6. flood discharging tunnel gentle slope according to any one of claims 1-5 and abrupt slope connection structure, it is characterised in that：It is described slow Slope section (1), steep slope section (2) and aeration structure (3) are built by the way of one-piece casting.