CN1046148C - Storring energy-dissipating method using profiled wide-tail block - Google Patents

Abstract

The present invention relates to a trajectory energy dissipation method using a heteromorphic flaring gate pier, which belongs to a discharge energy dissipation method for a discharge structure in the hydraulic engineering, and comprises: the present invention is formed by combining an original parallel guiding gate pier trajectory energy dissipation mode and a flaring gate pier trajectory energy dissipation mode, namely that the distance S between the bottom edge of the flaring empennage of the flaring gate pier and the surface of an overflow weir is not equal to 0, the layer of water flow between the bottom edge of the flaring empennage of the heteromorphic flaring gate pier and the surface of the overflow weir is basically identical with the water flow formed when a horizontal tail gate pier is used, and water flow above the altitude of the bottom edge of the flaring empennage is restricted by the flaring gate pier to form impact waves. When the method is used for energy dissipation, scour pools can be far away from dam toes, and the scour pools can be small and shallow; the present invention is a relatively ideal trajectory energy dissipation method.

Description

Storring energy-dissipating method using profiled wide-tail block

Storring energy-dissipating method using profiled wide-tail block belongs to outlet structure escape works sluicing energy dissipating method in the hydraulic engineering.

Key water control project all has outlet structure escape works in order to drain unnecessary flood.The flow rate of water flow of letting out under the outlet structure escape works is generally higher, if do not take engineering measure to eliminate the kinetic energy of the stream that sluices down, will wash away underwater bed, jeopardizes the safety of outlet structure escape works.

Flip trajectory bucket is a kind of energy dissipating mode of using often.

Traditional flip trajectory bucket mode is shown in Fig. 2.Its gate pier 8 is straight, it is with flip bucket 7, arrive the impelling of current elder generation aerial, mix a large amount of air, form the overflow of diffusion gradually, fall into the riverbed at a distance at the distance toe, and before and after main flow, form two and revolve greatly and roll, when the scouring capability that slips into the water thigh then forms scour hole during greater than the riverbed impact resistance.Flip trajectory bucket utilizes These characteristics exactly, and current are chosen from building as far as possible, make overflow aloft with the downstream water cushion in energy dissipating, formation dash the safety that building must not be jeopardized in the hole.But under a lot of concrete hydrology and geological conditions, traditional flip trajectory bucket usually can not meet the demands.

The seventies, China scientific and technical personnel once worked out flaring gate pier flip trajectory bucket method, promptly the downstream of the straight gate pier of routine were added that two empennage 2 (see figure 3)s form flaring gate pier 1.

Flaring gate pier comprises three parameters, L, l and θ (or b).Rising of flaring gate pier expanded point all in the torrent position, and when current flow through flaring gate pier, because the pier tail is widened, lock chamber shrinks along journey, the torrent turnover formed standing wave, and the water surface in the lock chamber is stopped up than higher.Generally, the intersection point of the standing wave that the flaring gate pier and arranged on left and right sides forms is all in the contraction section downstream, therefore at the terminal both sides height that forms of flaring gate pier, middle low " recessed " font flow section, increase with the contact surface of air, the air entrainment of current on dam facing is many when choosing stream than the horizontal tail pier, thereby can reduce the energy into water jet.In addition, when the water surface is stopped up in lock chamber when high, form certain included angle between water surface streamline and the dam facing streamline, promptly the flow velocity of each particle has different inclination angles on the dam facing normal direction, big more near water surface inclination angle more, therefore each layer water has further reduced the entry energy of single wide water surface at the width that has vertically widened overflow, thereby can reduce the degree of depth of erosion quantity and scour hole with different angle flip shot.But this flaring gate pier is chosen stream just because of the energy of flip shot current just reduces before choosing rising, thus flip shot apart from shortening, dash cheat nearer from the dam.Therefore after Pan members of a family have built test dam, three holes, there is not other engineering to adopt flaring gate pier to choose stream.

The objective of the invention is to adopt a kind of novel gate pier flip trajectory bucket, outlet structure escape works had both been had dash the hole when horizontal tail pier is chosen stream far away when draining flood, have again and dash the little and shallow advantage in hole when flaring gate pier is chosen stream from toe.

Content of the present invention is a Storring energy-dissipating method using profiled wide-tail block, the wide tail empennage root edge that is characterised in that flaring gate pier 1 apart from the overflow weir table and apart from S ≠ 0, form irregular broad tail, current when making the wide tail empennage root edge of irregular broad tail and that layer current between the overflow weir surface and horizontal tail pier are basic identical, and the above current of wide tail empennage root edge elevation are subjected to the restriction of flaring gate pier to form shock wave.

Design of the present invention is, raises wide tail empennage, makes S ≠ 0.Experiment shows, when S ≠ 0, current when that layer current between spillwag chute and flaring gate pier root edge and horizontal tail pier are basic identical, similar during it choose distance and horizontal tail pier and choose stream, but this strand current only account for the sub-fraction of total flow, entry aggregated momentum when therefore its entry aggregated momentum is chosen stream than horizontal tail pier is much smaller, and this strand current form separately, and to dash the hole also much smaller.But this strand current can become the carrier of upper water thigh again.In irregular broad tail, the current that flaring gate pier root edge elevation is above also have been subjected to the restriction of flaring gate pier, form shock wave.Though the end at irregular broad tail has formed opening " protruding " font flow channels, the active cross-section in pier tail downstream still is " recessed " font.But owing to be subjected to the jacking of bottom overflow, both sides water thigh is higher during than non-irregular broad tail.Choose stream with flaring gate pier and compare, irregular broad tail is subjected to the current of wide tail restriction few when choosing stream, so the additional energy dissipating before going out anti-arc end is lacked than flaring gate pier; After anti-segmental arc, stream thigh under the irregular broad tail has bigger flow velocity and chooses the angle flip shot with identical with bucket lip substantially, the most of water body after the flaring gate pier restriction on it form left and right two bursts of basic symmetries close gate pier center lines, choose the angle is chosen at the angle greater than bucket lip the higher high impelling current of ratio flaring gate pier.Like this, each lock hole all is upper and lower three bursts of current mutual restriction, interaction, advances together, further cut down energy and the entry total energy of jet be distributed in the bigger scope, therefore this irregular broad tail flip trajectory bucket method formation dash hole longer but more shallow than flaring gate pier.Key is to regulate the S value.

Description of drawings

Fig. 1 is the irregular broad tail schematic diagram

Fig. 2 is a horizontal tail pier schematic diagram

Fig. 3 is the flaring gate pier schematic diagram

Three kinds of typical gate piers dashed hole section comparison diagram when Fig. 4 was 133.88 meters of upper pond levels.

Following but one embodiment of the present of invention are described further the present invention in conjunction with the accompanying drawings.

As shown in Figure 1,5 is irregular broad tail among the figure, and 6 is the wide tail empennage of irregular broad tail, and 3 is overflow weir, and 7 is flip bucket.When upper pond level was 133.88 meters, two gate pier clear spacings were 12.0 meters, wide tail empennage 6 root edges apart from overflow weir 3 surfaces apart from S=2.5 rice.50.56 meters of overflow weir 3 length, the overflow weir surface configuration is as figure.

C1 point X ₁ ^1.85=2 * 16.1755 ^0.85yC ₂The point $\frac{X^{}}{}$ $\frac{{}^2}{{4.691}^2}+\frac{(2.701-Y{)}^2}{2.701^2}=1$ Anti-segmental arc is α ₁=48.66 °, α ₂=38 °, radius of curvature is 18.50 meters, and irregular broad tail 5 is wide 3 meters, and pier is long 32.39 meters, expands distance L=22.7 meter of point 10 from the point of the irregular broad tail of overflow weir peak correspondence apart from wide tail empennage, the long l=5.0 rice of wide tail empennage, the wide b=2.4 rice of wide tail empennage.

8 is the horizontal tail pier among Fig. 2.

1 is flaring gate pier among Fig. 3, and 2 is the wide tail empennage of flaring gate pier, at this moment S=0.

Three kinds of typical gate pier scour hole section configurations as seen from Figure 4, curve 11 is an irregular broad tail scour hole section, and the favourable opposition hole degree of depth is 13.7 meters, and it is corresponding that to dash the hole cross-sectional area be 1050 square metres.Curve 12 dashes the hole section for flaring gate pier, and the favourable opposition hole degree of depth is 18 meters, corresponding dash the hole disconnected and long-pending be 1200 square metres.Curve 13 is horizontal tail Dun Chong hole section, and the favourable opposition hole degree of depth is 26 meters, and corresponding to dash the hole cross-sectional area be 2400 square metres.

Effect of the present invention is conspicuous, dashes the advantage of hole away from toe when it had both kept horizontal tail pier flip trajectory bucket, dashes the little and shallow characteristics in hole when having the flaring gate pier flip trajectory bucket again, is a kind of more satisfactory new-type flip trajectory bucket method.

Claims (2)

1. Storring energy-dissipating method using profiled wide-tail block, wide tail empennage (2) root edge that it is characterized in that flaring gate pier (1) apart from overflow weir (3) surface apart from S ≠ 0, form irregular broad tail (5), current when making wide tail empennage (6) root edge of irregular broad tail (5) and that layer current between overflow weir (3) surface and horizontal tail pier are basic identical, and the above current of wide tail empennage (6) root edge elevation are subjected to the restriction of flaring gate pier to form shock wave.

2. Storring energy-dissipating method using profiled wide-tail block according to claim 1, the pier that it is characterized in that above-mentioned irregular broad tail (5) is grown 32.39 meters, and pier is wide 3 meters, long 5 meters of wide tail empennage (6), wide tail empennage (6) is wide 2.4 meters, wide tail empennage (6) apart from overflow weir (3) surface apart from S=2.5 rice.

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