The recommendations for the development of additional regulatory requirements to reliability of water supply systems in Vietnam are offered. In current construction rules for design, the reliability of water supply systems of water facilities is not standardized. Water systems are classified into three categories, for which the conditions for performing functions in the process of water supply for consumers are formulated. It is not provided to assess the quality of these functions quantitatively. Adoption of design decisions without quantitative assessment of their quality is violating a systematic approach in carrying out construction and design works, which has formed in the global practice. As a result of the research of water supply facilities’ reliability in Vietnam and Russia, the reliability of the existing water supply facilities has been estimated. On the basis of mathematical methods for assessing the reliability of technical objects, the methods for assessing the reliability of water supply facilities and their systems has been justified and systematized. If there is lack of reliability and security requirements to the object of capital construction for design documentation development or such requirements are not established, the development and approval in the prescribed manner of special specifications should precede the documentation development. It is proposed to systematize the statistical data gathering on the reliability of the equipment and facilities of water supply systems by uniform rules. Any designed objects of water supply must have a quantitative estimate of the level of reliability. The outlined methods for assessing the reliability of water supply facilities and systems can be used in the formation of regulatory requirements for reliability in the design of water supply facilities in Vietnam.

The noise state in buildings is a general process of sound energy distribution in the building volume. The sound energy emerging in separate rooms falls on enveloping structures of the rooms and penetrates to the adjacent volumes. In this case the enveloping structures of the noisy rooms become the sources of noise for other rooms. In public buildings flat rooms widely occur, in which the noise from technical rooms often penetrate. The authors observe the principles of evaluating indoor noise in a flat, which penetrates from adjacent premises through the walls. The method of calculating sound pressure levels in rooms is offered. The method takes into account the patterns of direct sound distribution from the flat noise source (wall) and the conditions of the reflected sound field creation in flat space of finite and infinite length. The direct sound energy distribution character is determined by geometric parameters of the wall shedding the noise. The method provides the desired calculation precision of the sound pressure levels.

Bending plate is widely used in the construction of large-span structures. Its advantage is light weight, industrial production, low cost and easy installation. Implementing the algorithm for calculating bending plates in engineering practice is an important issue of the construction science. The generalized equations of finite difference method is a new trend in the calculation of building construction. FDM with generalized equation provides additional options for an engineer along with other methods (FEM). In the article the algorithm for dynamic calculation of thin bending plates basing on FDM was developed. The computer programs for dynamic calculation were created on the basis of the algorithm. The authors come to the conclusion that the more simple equations of FDM can be used in case of solving the impulse load problems in dynamic load calculation of thin bending plate.

Criteria of plasticity and durability derivative of standard indicators of plasticity (δ, ψ) and durability (σ
_0,2, σ
_B) are offered. Criteria К
_δψ and К
_s follow from the equation of relative indicators of durability and plasticity. The purpose of the researches is the establishment of interrelation of derivative criteria with the Page indicator. The values of derivative criteria were defined for steels 50X and 50XH after processing by cold, and also for steels 50G2 and 38HGN after sorbitizing. It was established that the sum of the offered derivative criteria of plasticity and durability С
_к considered for the steels is almost equal to unit and corresponds to a square root of relative durability and plasticity criterion C
^0,5. Both criteria testify to two-unity opposite processes of deformation and resistance to deformation. By means of the equations for S
_к and С it is possible to calculate an indicator of uniform plastic deformation of σ
_р and through it to estimate synergetic criteria - true tension and specific energy of deformation and destruction of metal materials. On the basis of the received results the expressions for assessing the uniform and concentrated components of plastic deformation are established. The preference of the dependence of uniform relative lengthening from a cubic root of criterion К
_δψ, and also to work of the criteria of relative lengthening and relative durability is given. The advantage of the formulas consists in simplicity and efficiency of calculation, in ensuring necessary accuracy of calculation of the size δ
_р for the subsequent calculation of structural and power (synergetic) criteria of reliability of metals.

The article discusses the features of the stress state of the plate of capitalless girderless overlapping as a result of force of prestressed reinforcement, where the reinforcement used is high-strength reinforcement in flexible shell of "Monostrend" type. The peculiarity of specific design solution is a diagonal arrangement of prestressed reinforcement with heads fixed at the outer edges of the columns. The purpose of this arrangement of the prestressed reinforcement is deflection reduction of the central area of a plate and reduction of the width of cracks on the lower surface in the bay and on the upper surface of the support areas. The article shows the distribution of normal stresses of existing loads in the plane plate. The stress distribution over the thickness of the plate was assumed uniform. In order to establish design size of a section in diagonal direction it is possible to set the variables x and y and then calculate the coordinates of stress distribution curves in the concrete as a result of compression by prestress force. The authors offer diameter values of equal stresses in case of 4 and 8 K7O ropes. The method of calculating prestressing losses of concrete creep are offered.

The method of localization of changes in the deflected mode is based on the analysis of time series of oscillations (displacement, velocity, acceleration) of building constructions and structures. The method is based on the hypothesis that any changes in the deflected mode of structures result in changes in the oscillation energy. In this case, once the information on the structure oscillation parameters in different points of the building is available, the changes in the oscillation energy will signify the changes in the deflected mode in the relevant points.

The research of raw base for construction materials allows theoretically justifying and experimentally confirming the ability to control the processes of structure formation in order to obtain materials with the desired properties. Clay matter has a complicated chemical and mineral composition. In recent decades the structures and properties of clay minerals have been investigated in detail with the help of modern research methods. Out of the whole quantity of clay deposits the production sector uses only the small part, which satisfies the standard technical documents in force. In case of using non-traditional clay rocks in the production of wall materials it is possible to cross over from traditional raw materials to another - composite binder, obtained on the basis of natural nanodispersed raw material, which helps to speed up neoformation synthesis, change their morphology, optimize microstructure of cementing compounds and consequently improve physical and mathematical properties of the products. Using non-traditional for construction industry clay rocks in the production of silicate materials increases the strength of raw-brick 4...11 times, which facilitates the production of high cavitated product and significantly expands the range of products.

A water supply system of a special purpose is a necessary element in hot and cold shops of the industrial enterprises, office buildings and the medical centers, and also other rooms. The water supply systems of a special purpose, which give subsalty, sparkling water and water sated with oxygen, allow people to prevent, for example, strong dehydration of an organism, which is possible at big losses of water, especially in case of the people working in hot shops. Various elements of special drinking water supply system are given in the article, their main functions are described. Different types of the water folding devices pumping water to consumers, one of which is drinking fountain, are considered. Possible systems of water filtration, which can be established for quality improvement, are transferred. Among them the great role is played by membrane technologies and the return osmosis, which is widely applied now. Today there is a possibility of construction, both the centralized water supply system of a special purpose, and local. Besides, the least is a more preferable option taking into account capital expenditure for construction and operation, and also it can lead to solid resource-saving as a result of the electric energy saving going for water heating in heaters. Automatic machines of drinking water for a local water supply system of a special purpose have indisputable advantages. They are capable to carry out several functions at the same time, and also to distribute water to consumers. It allows placing all the necessary equipment, which will be well in harmony with the environment in their small and compact case, and will fit into any difficult interior of the room. Also they are very easily connected to the systems of an internal water supply system by means of a propylene tube that allows to change their sposition in space and to transfer to any place of the room with fast installation of equipment. Also the ecological effect was proved upon transition from coolers on machine guns of drinking water that allowed refusing the order of plastic bottles, which after use start accumulating on dumps, polluting the environment.

The deformation of municipal solid waste is a complex process caused by the nature of MSW, the properties of which differ from the properties of common soils. The mass of municipal solid waste shows the mixed behaviour partially similar to granular soils, and partially - to cohesive. So, one of mechanical characteristics of MSW is the cohesion typical to cohesive soils, but at the same time the filtration coefficient of MSW has an order of 1 m/day that is characteristic for granular soils. It has been established that MSW massif can be simulated like the soil reinforced by randomly oriented fibers. Today a significant amount of the verified and well proved software products are available for numerical modelling of soils. The majority of them use finite element method (FEM). The soft soil creep model (SSC-model) seems to be the most suitable for modelling of municipal solid waste, as it allows estimating the development of settlements in time with separation of primary and secondary consolidation. Unlike the soft soil, one of the factors of secondary consolidation of MSW is biological degradation, the influence of which is possible to consider at the definition of the modified parameters essential for soft soil model. Application of soft soil creep model allows carrying out the calculation of stress-strain state of waste from the beginning of landfill filling up to any moment of time both during the period of operation and in postclosure period. The comparative calculation presented in the paper is executed in Plaxis software using the soft-soil creep model in contrast to the calculation using the composite model of MSW. All the characteristics for SSC-model were derived from the composite model. The comparative results demonstrate the advantage of SSC-model for prediction of the development of MSW stress-strain state. As far as after the completion of the biodegradation processes MSW behaviour is similar to cohesion-like soils, the demonstrated approach seems to be useful for the design of waste piles as the basement for different constructions considering it as one of remediation techniques for the territories occupied by the old waste.

This article focuses on the method of improving shear stresses calculation accuracy based on the experimental data. It was proven that shear stresses value considerably changes (even up to change of sign from positive to negative) depending on different velocity fluctuations amount (or length). Experimental database consists of velocity in turbulent flow at different times. Recommendations for practical use of methods of calculation depending on the type of engineering problems are presented. The method of finding optimal amount of the experimental database is proposed by the analysis of the values convergence of the standard deviations calculated for the whole sample and the standard deviation calculated by increasing interval. The calculation results for these intervals are at the points of the measuring system and the hypothesis about finding the optimal length of implementation is offered. The steps for further research are set out.

In the process of calculating and simulating water discharge in free channels it is necessary to know the flow features in case of small values of Reynolds and Weber numbers. The article considers the influence of viscosity and surface tension on the coefficient of a weir flow with sharp threshold. In the article the technique of carrying out experiments is stated, the equation is presented, which considers the influence of all factors: pressure over a spillway threshold, threshold height over a course bottom, speed of liquid, liquid density, dynamic viscosity, superficial tension, gravity acceleration, unit discharge, the width of the course. The surface tension and liquid density for the applied liquids changed a little. In the rectangular tray (6000x100x200) spillway with a sharp threshold was established. It is shown that weir flow coefficient depends on Reynolds number (in case Re < ~ 2000) and Webers number. A generalized expression for determining weir flow coefficient considering the influence of the forces of viscosity and surface tension is received.

In the article the authors estimate the possibility of building a high (100 m high) stone dam with clay-cement concrete diaphragm. This diaphragm is used as an antifiltering element and it is made of secant piles method of clay-cement concrete (method of "slurry wall"). This diaphragm should be constructed in several phases, in our example example in three stages. Numerical studies of the stress-strain state of such a dam show that considerable compressive stresses can appear in the diaphragm. These stresses can be significantly (3...4 times) greater than the strength of clay-cement concrete in compression. However it should be taken into consideration that the diaphragm of such a high dam will be crimped by horizontal stresses, i.e. clay-cement concrete will operate in the triaxial compression. Under these conditions the strength of clay-cement concrete will be significantly higher, therefore, the diaphragm reliability might be provided with a margin. For this reason, the most important issue in the engineering of a high dam with such type of diaphragm is to select the required composition of clay-cement concrete. Increasing its strength by extension of the cement fraction could increase modulus of deformation. Therefore it could lead to compressive stress increase and the strength state degradation. Hydrostatic pressure generates the areas of tensile stresses in the clay-cement concrete diaphragm due to the arising bending deformation. It threatens the formation of cracks in the clay-cement concrete, especially in the nodes interface diaphragm queues. It is recommended to match the diaphragm queues using ferroconcrete galleries. This should ensure flexibility of deformation between the gallery and the diaphragm.

This article deals with the problem of criteria optimization in order to objectively evaluate the experience of an applicant (a project organization) and the quality of a design product (project documentation). The methodology to be developed is based on introduction of new evaluation criteria (sub-criteria) that in conjunction with the applicable criteria specified by the Law on the Contract System will allow developing the optimal procedure to evaluate competitive bids of the participants in tenders and determining the most appropriate candidate, with whom the contract will be further concluded. The article analyzes the existing criteria and their interaction with each other and describes the specifics of tenders for design in the form of open competition. The list decreases to three criteria, such as "contract price", "quality, functional and environmental characteristics of a procurement facility", "qualification of procurement participants, including availability of financial resources, equipment and other material resources necessary for the execution of the contract material resources, the presence of goodwill, professionals and other employees of a certain experience level". However, in order to upgrade the quality of assurance procedures for the design works to be performed, it was decided to apply new evaluation criteria (sub-criteria) components, such as "availability of positive findings of the state out-of-departmental examination that are similar to the subject of competition, on a participant in placement of order", "availability of the certificate on approval of architectural and urban planning decisions that are similar to the subject of competition, on a participant in placement of order", "availability of the permit for the commissioning of facilities that are similar to the subject of competition, on a participant in placement of order", "availability of the contract for designer's supervision with a participant in placement of order". The article describes in detail the above evaluation criteria (sub-criteria) and presents a new procedure of evaluation of competitive bids, which will allow combining its new components with those existing under the law and giving the actual result of their interaction with each other in determination of a winner, i.e. a more well-deserved candidate (a tenderer). Thus the requirements given above are met, the participants in order placement will be able to declare themselves as organizations that are highly skilled, fair and able to perform the high-quality design works, know how to perform work in due time and in strict compliance with the current regulations of the Russian Federation and are able not only to show a creative approach to solving the objectives, but also to create a project characterized by both architectural and artistic aesthetics and its high technological effectiveness.

The design decision is usually a synthesis of various requirements to the construction object. The main difficulty is to approve the solution results of all the subtasks, because these various requirements often contradict each other. In the article the existing approaches to design solutions searching for steel structural designs are considered, features of standard and individual design are specified. The associative method of choosing the design decision is offered. The process of search is directed in order to receive favorable coincidence of design situations, current and implemented earlier and to apply the approved decisions. In order to consider the greatest possible quantity of combinations of design solution for structural designs in the article it is offered to create a tree of enumeration of possibilities for decisions, in case of which the possible values of decision parameters vary. The algorithm of searching the design decision is shown by a method of a tree of search creation. Three levels of solution for a problem of steel structural designs are thus described. Also the question is raised of the effectiveness of padding expenses for creating the complete tree of search of options, their analysis and assessment.

The discrete analysis methods, in particular the theory of graphs, are widely recognized as a tool for building mathematical model, including in construction. In the process of design documentation formation there always appears the necessity to plan project networks. At the present moment there is no reasonable generic program, which helps the designer to rapidly solve this task. The authors present the possibilities of using the generic program for Windows developed by them. The program allows solving key tasks of the theory of graphs. These tasks include the search (calculation) of the critical (project network planning) or optimal (resources delivery variant) path in the graph. The process (user interface) of graph formation corresponding to the target network in frames of the program is described. On the stage of construction project development there always appears a task of visual image of workflow process as a graph. So the project network is an image of an object erection. At that the events are depicted as rings, and works - as branches (arrows). The general view of the dialog box with the description of the possibilities of editing (adding and deleting vertexes and edges), saving the document, reading the document from file as well as optimal and critical paths are presented.

The physical reasons for building structures destruction are both the forces arising at stress-strain state of construction elements and external influences arising at emergency situations, as well as their moments, impulses and periodic impulses with the frequencies close to of fluctuations frequencies of construction elements. We shall call the mathematical calculation models for the parameters-reasons of destructions the basic models. The basic models of destruction of building structures elements allow not only providing necessary level of reliability and survivability of the elements and the construction as a whole already at the stage of their design, but also giving the chance, at their corresponding completion, to provide rational decisions on the general need of recovery works and their volume depending on destruction level. Especially important for rational design decisions development, which ensure the demanded constructional safety of building structures, is library creation of the basic mathematical models of standard processes of bearing elements destructions for standard construction designs for the purpose of the further forecast (assessment) of the level and probabilities of standard destructions. Some basic mathematical models of destructions processes of the standard elements of building structures are presented in the present article. A model of accounting for construction defects and a model of obtaining requirements to probabilities of partial destructions of a construction are given. Both of these models are probabilistic.

The Desargue configuration plays an essential role not only in projective geometry, being the main configuration in projective and perspective correspondence of rows of points and lines, but is also rich in applications in architectural and design engineering. The article describes the main aspects of planar and spatial configuration of Desargue, and fundamental principles having particular importance in the shaping theory based on projectography. The described configuration properties indicate the possibility of wide application in architectural design and engineering and allow predicting the effects of perception of rather complex architectural forms. Examples of a number of buildings are given, where in modern design solutions of architects spatial configuration motives are visible. Planar configuration option is often used as decoration and fencing. The authors conclude that researching the configuration of Desargue in different variants and modifications not only contributes to better understanding of the theory of perspective and shadows, but also provides opportunity to detect relations of the problems, which are different at the first sight. However it is necessary to take into account, that many postulates of the theory are quite complicated and significant amount of time is needed for learning it.

During the current decades the aspect of geometrography compositions formation on the basis of basic images has been actively developed. The basic images possess the qualities of harmonies, expressed by lines, squares, tone, color. The relations of square-rectangular forms belonging to plane geometry of parabolic, hyperbolic and elliptic fields has been already analyzed by scientists. This article introduces equiareals construction of square-rectangular shapes, as well as their rows - in classical composition of elementary figures of "squaring the circle". Variations of such constructions, in their turn, offer the possibility to seek and capture new geometrical graphical compositions, practical application of which can be wide enough in technology design and mechanical engineering, architecture and construction, decoration of household items, arts and crafts and costume fabrics, et cetera. The authors consider the topic of plane geometry "Field-M", which is based on a rectilinear grid of ortholines with circulations in its nodal points. The conclusions made by the authors is that the necessity of solutions for more and more various and complicated problems in the conditions of time limitation determines the development of geometrography methods as an effective operating system along with program methods of cognitive graphics.