In many hydraulic structures it is necessary to improve the physicomechanical properties of fissured ledge rock in the foundation. In practice, this is usually carried out by cement grouting, which aims at making the rock monolithic, strengthening it, and increasing its modulus of deformation [1]. The way in which cementation by grouting of ledge rock affects its deformability under compressive loads has been widely investigated in the USSR [2, 3] and abroad; however, the effect on the shear strength along fissures has so far been studied only in a few papers.At the Laboratory of Soil Mechanics of the Siberian Branch of the B. E. Vedeneev All-Union Scientific-Research Institute of Hydrotechnology (VNIIG), experiments in 1964(VNIIG), experiments in -1965 showed that cementation of cracks in ledge rocks markedly reduces the shear deformation; increase in the resistance to shear forces was not so marked. Thus shear deformations of a cemented fissured granite pillar, 8 x 12 m in plan, at the Krasnoyarsk hydroelectric station (experiments by D. D. Sapegin) were lower by a factor of 4.5-6 than the corresponding deformations of a noncemented pillar, but the increase in shear breaking strength was only 7 -1 0 % ( i n limiting equilibrium). Experiments on gneisses atthe Naglu hydroelectric station (experiments by R. A. Shiryaev) gave similar results: the increase in the limiting shear loads was only 3-10fie. On the other hand, there are indications in the literature [4] that cement grou ti~g of markedly fissured rocks increases the shear strength-however, no numetical values are given for this increase. "

the article describes the problems of assessing the anthropogenic impact of human activity on natural com-plexes surrounding urbanized territories. Among the main research tasks are development of methodological foundations for assessing the quanti-tative and qualitative composition at anthropogenic impact on natural complexes surrounding urban areas. The main method of this research include a dialectical approach that focuses on generally accepted logi-cal research methods (analysis, systematic approach, generalization) and their synthesis using relevant in-formation materials. The author considered various methods of assessing the impact of various factors on the environment, and also carried out the examination of urban decisions related to the appointment of a category (status) the natural resources included in the urban environment in Moscow. The Russian capital is a European metropolis, the largest city-millionaire in Europe and a typical object of research to identify the effects of various anthropogenic factors. The implementation at economic activity in the metropolis is accompanied by the emergence of problems, the solution of which has not been found yet. Analysis of methods for assessing the impact at the various factors on the environment was carried out taking into account the provisions in regulatory documents governing the appointment for protected areas urban environment. Provisions of regulatory documents and decisions of executive authorities designed to use natural (forest) resources in urban environments. The absence of approved methods for assessing certain types of land plots with a protected status was identified. The main factors affecting the quality of biogeocenosis were identified. The main features of the applica-tion methods for assessing the status and possibility in recreational development in territories of varying de-grees at development are considered.

The concrete spillway dam of the Gor'kii hydroelectric station ( Fig. 1) with a head of 17 m, is 286 m lon~ including piers and left-bank abutment and has a base width of 39 m.* The powerhouse abuts the dam from the right bank.The dam is founded on rocks of the Sarma suite of the Tatarian stage, represented by clays and sands with nonpersistent interlayers of marls, siltstones, and sandstones. Rocks of the Urmzhum suite, which are virtually a confining bed, occur lower. Among the rocks of the Sarma suite a special place is occupied by sands which form two member~ in the region of the concrete dam: an upper member with an average thickness of 3 m occurring in the roof and a lower, more persistent member reaching a thickness of 5 m. The thickness of the entire suite is about 12 m.An L-shaped cutoff curtain was comtructed in front of the dam to create a barrier to seepage flow and to reduce uplift. It comists of a vertical, massive, reinforced-concrete wall cut into the Urzhum rocks and a horizontal, reinforced-concrete slab, not connected with the dam body, which is laid on a concrete bed and covered with an asphalt-concrete slab and loam apron. The vertical and horizontal parts of the curtain are separated by settlement joints with waterproof keys. The longitudinal axis of the vertical part of the curtain is parallel to the dam axis, stands 15 m from its upstream face, and is turned under the left-bank abutment toward the lower pool. Over the entire length of the dam, between the heel and the toe, is laid a drain in the form of a graded filter, in the front part of which is a row of 33 drain welis (d = 0.7 m, spacing 8 m) for draining the seepage waters into the lower pool The walls are hermetically sealed. The water drains from them into the lower pool along one of two pipelines (working and repair). All branch pipes connecting the walls with the pipelines have cast-iron valves which permit disconnecting any well from the system. Each main pipeline has four outlets into the lower pool, on which are also mounted valves for disconnecting the system from the lower pool.To determine the seepage discharge entering the fiat drain, the working pipeline (d = 150 ram) has VV-50 flowmeters, which to some extent hamper drainage of the seepage flow owing to narrowing of the pipeline to 50 mm at the places where the flowmeters are installed. Therefore, the water is presently being drained along both pipekines simultaneously.By the time the investigations began, the station had been operating for about 10 years. During this time the drainage collector system had been repaired only partially. In some places a yeUow and dark-brown jellylike mass had formed on the surface of the valves and wells as a result of the activity of iron bacteria. Whether such formations were within the wells or pipes could be determined oniy by investigating the entire system during repairs.To repair the drainage system, including inspection of the covers of the relief wells and all valves, it was necessary to disconnect completely the fiat drain, whic...

In the author's previously published works a method was proposed for calculating the strength of rigid watertight diaphragms in earth dams without consideration of the friction of the earth of the shoulders on the surface of the diaphragm. The assumptions made by the author are confirmed by the data of experimental investigations conducted by him. However, experiments in a flume of comparatively small height (1.18 m) did not permit evaluating with certainty the effect of friction of-the earth of the soulder on the diaphragm. Recommendations on taking this effect into account are given in the present article.A correct determination of the direction of action of the frictional forces of the shoulder earth on the diaphragm surface is quite important. It is assumed that the following normal and tangential forces act on the surface of a rigid diaphragm (Fig. i).In the given calculation scheme, to the surface from the side of the upper pool are transmitted:the total hydrostatic pressure and the difference of the horizontal components of the active earth pressure of the upstream and downstream shoulders of the dam; these forces are expressed by the angular coefficient u of a triangular diagram of height H, which includes the pressure of the water, buoyed earth of the upstream shoulder, and dry earth of the downstream shoulder of the dam 0.5 ~H~; vertical component Pz,'of the pressure of the earth and water, defined as the weight of the water and earth wedge between the inclined surface of the diaphragm and vertical plane tangent to it; frictional force of the earth of the upstream shoulder of the dam on the diaphragm surface T~ directed down a vertical contacting the diaphragm at its base under the assumption that the settlement of the shoulder is greater than the settlement of the diaphragm, and moreover the diaphragm, moving, is displaced upward relative to the earth of the upstream shoulder; this force is expressed by the lateral pressure of the soil of the upstream shoulder submerged in water multiplied by the coefficient of friction tan ~z of the soil on the diaphragm surface, which is expressed by the equation

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