ECOLOGICAL SANATION OF TE (Thermoelectric Plant of otanj) - CONSTRUCTION OF HIGH DAM MADE FROM SLAG, ASH AND FUME DESULPHURIZATION PRODUCTS ON A SUBSIDING AREA

TE(otanj电厂)的生态修护作用-利用矿渣、粉灰和烟灰在沉陷区域建造高坝

Study on model law for intensity of rainfall from atomization of flood-discharging flow for high dam

According to the statistics at the beginning of nineties of 20th century,among the constructed and being constructed high dam, ECRD is in the proportion of 55.5% around the world.

A lot of planned hydropower projects that the height of its dams are up to 200 to 300 meters and the spillway discharges are 20,000 to 50,000 m3/s, will be founded in the 21st century, this will challenge the high dam hydraulics for some new problems.

The Longtan hydropower station includes a high RCC gravity dam with a height of 216.5 meters. It will be constructed by two stages. In the first stage a 192 m high dam will be built.

With the development of worker's theory of the dam and science and technology, the construction of high dam prevails day by day, in order to meet the demand that people increase day by day, the dam is increasing constantly high, the size of high dam changes with each passing day, high dam water flow state more and more difficult to control, so high dam water flow state sluice research, building of object type wave in the outstanding position more and more.

-We have examined the digital waveform data and relocated a number of events within the June 1987 earthquake swarm, which occurred beneath the northern part of Lake Aswan, 70 km southwest of the Aswan High Dam in Egypt.

Previous estimates of average annual evaporation from the lake formed by the High Dam at Aswan, Egypt, fall in the range from 4.65 mm d-1 to 7.95 mm d-1.

Net radiation has been measured for the first time over the Aswan High Dam Lake on the Nile River for 132 days including warm and cold seasons.

Effect of storage reservoirs on the behavior of rock masses of high dam beds

Measurement of the upper pool levels of a high dam during construction

To be able to locate the point of inception of air entrainment is of considerable significance in the design of ski-jump spillways for high dams, in that this is not only prerequisite to the theoretical analysis of jet diffusion in the air and the subsequent alleviation of erosion as the aerated jet dives to the bed, but also essential if the possible benefit of aeration in the reduction of concrete pitting is to be evaluated. Although past contributions to this problem are numerous, no method has yet...

To be able to locate the point of inception of air entrainment is of considerable significance in the design of ski-jump spillways for high dams, in that this is not only prerequisite to the theoretical analysis of jet diffusion in the air and the subsequent alleviation of erosion as the aerated jet dives to the bed, but also essential if the possible benefit of aeration in the reduction of concrete pitting is to be evaluated. Although past contributions to this problem are numerous, no method has yet been available to yield the correct prediction of the onset of aeration in or downstream of the curvilinear portion of the spillway which is known to take place much earlier than usual. Even for the straight portion of the spillway, calculated positions of aeration inception do not always match with the observed values (see table 1, and compare columns 4 to 7). In this paper is presented a rational and yet rather simple procedure with which one may treat the general problem of locating the position of aeration inception no matter if the spillway contains a curve or not. In the first place, the irrotational or "ambient" flow outside of the boundary layer is studied. In view of the fact that the flow over the spillway of a high dam is much smaller in extent laterally than longitudinally, an approximation similar to that used in the derivation of boundary layer equations from the Navier-Stokes equations is applied to the Euler equations. The resulting expressions indicate that the usual assumption of concentric streamlines is justifiable. The depth of flow is taken as that so calculated plus the displacement thickness of the boundary layer. Since on the plane of the complex potential, the flow over a spillway may be formulated as a simply-mixed boundaryvalue problem, Wood's exact method is applied to a numerical example with gravitational effect taken into consideration. The result of calculation indicates that both methods yield practically the same depth of flow. The inception of aeration is, as usual, assumed to occur as the boundary layer meets the free surface. Under the combined influence of gravity and boundary geometry, the flow over a dam is continuously accelerated or decelerated. In such case, boundary-layer computation by usual method is both involved and of doubtful accuracy. It is found, however, that in the case of flow over a spillway, the flow outside of the turbulent boundary layer conforms to a condition of self-preservation as proposed by Townsend. Since the Reynolds number for high dams may surely reach very high values, the turbulent boundary layer itself may be assumed to be approximately self-preserving. In short, this means that Townsend's theory of approximate self-preservation for boundary layers under the influence of longitudinal acceleration may be applied. This also means that the computation of boundary layer development may be much simplified. Based on an analysis of prototype data, it is found that in the present case involving air-entrainment inception, thickness of the boundary layer should be defined as that at which the mean velocity is within 0.1% of the velocity of flow outside the boundary layer. In the carrying out of the computations, boundary layer thickness at various sections are first estimated, then the irrotational flow outside the boundary layer is analysed by the simplified method to obtain the surface profile and the parameter "a" denoting the variation of velocity along the surface, and finally Townsend's theory of approximate self-preservation is applied to recompute the thickness of the boundary layer along the spillway. As any error made in the estimation of boundary-layer thickness has little effect on the computation of surface profile and hence on any subsequent computations, reasonably experienced computers should find it unnecessary to repeat the computations. Results of computations are found to be within 10% of the observed data obtained at two dams.

The paper describes the compaction characteristics of clayey soil. In view of the basic conception that the optimum degree of saturation Srop under various compaction energy is constant, and the optimum moisture content of the standard compaction energy is approximately the plastic limit, a method by using plastic limit wP and optimum saturation for estimation of the maximum dry density is presented as follows:γdmax=Srop·G3/G3wp+Sropwhere G3 is the specific gravity of the soil particles,wP is the plastic limit.Methods...

The paper describes the compaction characteristics of clayey soil. In view of the basic conception that the optimum degree of saturation Srop under various compaction energy is constant, and the optimum moisture content of the standard compaction energy is approximately the plastic limit, a method by using plastic limit wP and optimum saturation for estimation of the maximum dry density is presented as follows:γdmax=Srop·G3/G3wp+Sropwhere G3 is the specific gravity of the soil particles,wP is the plastic limit.Methods of determining the compaction criterion of clayey soil are discussed and the coefficient of construction m is introduced and demonstrated with suggestion value 0.95~0.97 for medium and low dams, and 0.97~0.99 for high dams.

A curve of equal cavitation number ( abbreviated as ECN curve ) is proposed for buckets of high-dam spillways. Based on simplified analysis, equations for the calculation of such a curve have been developed. These equations may be conveniently solved by a Runge-Kutta scheme. Applications to high-dam spillways show that the effective head of a spillway as far as cavitation potential is concerned may be materially reduced by adopting the ECN curve for the bucket. In one case, the effective...

A curve of equal cavitation number ( abbreviated as ECN curve ) is proposed for buckets of high-dam spillways. Based on simplified analysis, equations for the calculation of such a curve have been developed. These equations may be conveniently solved by a Runge-Kutta scheme. Applications to high-dam spillways show that the effective head of a spillway as far as cavitation potential is concerned may be materially reduced by adopting the ECN curve for the bucket. In one case, the effective head of a spillway with a drop of 111.5m is thus reduced to 62m.