1、1Study on the Problems in Municipal Water Supply and Drainage DesignsAbstract: Along with the rapid development of Chinas economy, the process of urbanization is constantly accelerated. The water supply and drainage engineering of municipal works is one of the most important components of the infras
2、tructures in urban areas. Besides, the water supply and drainage design of municipal works is a very important link. Whether the water supply and drainage engineering of municipal works can be done well is of important significance and role in the construction of a good urban living environment. In
3、the 21st century, it is necessary for urban construction to seek a sustainable development way, and promote the idea of energy conservation. This proposes higher requirement on the municipal water supply and drainage design. However, at present, there are still a lot of problems in the municipal wat
4、er supply and drainage design. Therefore, the author carries out a study on the problems necessary to notice in the municipal water supply and drainage design. Key words: Municipal Works; Water Supply and Drainage 2Design; Problems Necessary to Notice; Study Municipal water supply and drainage engin
5、eering is one of the most important components of the infrastructures in urban areas. The municipal water supply and drainage facilities can ensure the water on the ground of urban areas to drain away in time, and simultaneously can effectively prevent the water pollution in urban areas. Also, munic
6、ipal water supply and drainage facilities are necessary infrastructures for making urban water resource reasonably utilized and ensuring a virtuous circle of water resource. According to investigations, the construction of Chinas water supply and drainage engineering was started from the 1950s, and
7、the municipal water supply and drainage facilities attained a fast development in the 1980s. However, there are still a great number of problems universally in the municipal water supply and drainage facilities. Therefore, it is necessary for the municipal water supply and drainage design to be reas
8、onable, and hence give full play to the economic and investment benefits of municipal works. 1 Intension of Municipal Water Supply and Drainage Design Municipal water supply engineering refers to a complete 3systematic engineering, including getting water from water source, purification, delivery an
9、d circulation. Municipal water supply and drainage refer to the stream flows of industrial waste water, urban sewage, and atmospheric precipitation (including rain and snow water) and the delivery, collection, purification, utilization and discharge systems of other waste water. Municipal water supp
10、ly and drainage engineering design refers to a design of municipal water supply and drainage facilities constructed on municipal roads for delivering clean water, and collecting and discharging urban sewage and rain. Code for Urban Water Supply Engineering Planning, Code for Urban Water Drainage Eng
11、ineering Planning, Code for Design of Outdoor Water Supply Engineering, and Code for Design of Outdoor Water Drainage Engineering are four important bases for Chinese municipal water supply and drainage engineering plans and designs. Municipal water supply and drainage engineering design is a system
12、atic and complete process, and the purpose of planning and designing the water supply and drainage engineering is to make the delivery, collection, purification, emission and utilization abilities of the water drainage system improved in the planning and designing process. At the same time, it is ne
13、cessary to achieve unity and harmony in these 4links, ultimately making all links and the construction project of municipal water supply and drainage facilities proper in scales and reasonable in investment. Thus, resources and energy can be utilized better and more reasonably in operation. 2 Proble
14、ms in the Municipal Water Supply Engineering Design At present, problems in municipal water supply engineering design can be mainly concluded as follows. 2.1 Unreasonable Water Demand Prediction before Municipal Water Engineering Design Under normal circumstances, the prediction of municipal water e
15、ngineering design on water demand only gives consideration to the requirements of industrial production and domestic water. However, the prediction on the demands of internal rivers and rivers due ecological flows within the area of the municipal water engineering design is far from being sufficient
16、, and the actual water demand is often predicted to be more or less. In addition, the use amount of the comprehensive domestic water including the water for the life of residents, public buildings and facilities, fire control, watering roads and green grounds has not been predicted inaccurately. In
17、such a way, the prediction on the water demand will be ultimately unreasonable. 52.2 Unreasonable Selection of Water Supply System The selection of the water supply system in Chinese municipal water supply plan and design is still not very reasonable. Also, full consideration is not given to the eff
18、ects of high-position pools and water towers on the daily variation coefficient of water supply, as well as the extensibility. Also, there are no reasonable determinations on the reserves for water drainage pipes and the sizes of water drainage pipe diameters when road pipelines are comprehensive in
19、to a pipelines network, thus giving rise to the repeated investments and the insufficient play of the maximum economic and social benefits. 2.3 Selection of Water Supply Pipe Materials China owns a vast territory, and also the geology condition, climate, and low water quality of many places are diff
20、erent. Therefore, in the designing, it is necessary to select water supply pipe materials according to the specific actual conditions of all places, so as to effectively prevent the erosion of external conditions, ensure the supplied water quality not to suffer a secondary pollution, and also make t
21、he service life of the pipes network longer. 63 Problems in Municipal Drainage Engineering Design 3.1 Unreasonable Selection of Combined Intercepting System and Separate System Under normal circumstances, separate system is selected for the design of municipal water drainage engineering of urban are
22、as and especially the municipal water drainage of new urban areas; combined intercepting system is selected for the modification and design of water drainage pipes network of old urban areas. However, in a realistic sense, it is difficult to realize practice operations of separate system, and also t
23、he pollution from the early rain cant be ignored. In the design of Chinas municipal water drainage engineering, the factors such as economy, reasonability, and easy-to-construct and low pollution are not fully taken into account. As a result, the selection of combined intercepting system and separat
24、e system is not enough reasonable. 3.2 Unreasonable Sewage Treatment Schemes In the planning and designing of municipal drainage engineering, the contents of urban sewages are not fully considered, the determination of sewage pipes network and drainage area is not enough accurate and standard in cal
25、culation, and also the applied calculation methods are not 7enough scientific, thus making the calculation on the treatment of sewage not enough accurate. Besides, the new technology, new science and new materials are not fully utilized for processing the sewage in urban areas; the efforts on proces
26、sing the sewage are not sufficient; the guideline and principles of sustainable development, reuse, energy conservation and environmental protection are not always maintained in processing the sewage. 3.3 Municipal Water Supply and Drainage Plan and Design are Inharmonious with the Urban Land Flood
27、Control and Vertical Design Planning This respect is mainly manifested in the designing and planning of new urban areas. However, in the municipal water supply and drainage plan and design, the urban land vertical design planning is not fully taken account, and also the consequences caused by the un
28、smooth drainage in the water supply and drainage engineering area and the importance of the engineering area are not considered. This makes the flood control ability of municipal water supply and drainage poor. That is, once there is heavy rain, there will be unsmooth rain drainage. Therefore, the p
29、lanning and designing of municipal water supply and drainage is seriously inharmonious with the 8urban land flood control and vertical design planning. 3.4 Some Necessary Landscape Designs are ignored in Municipal Water Supply and Drainage Engineering In the design of Chinas municipal water supply a
30、nd drainage engineering, the water landscape designs are not fully taken into account, and some necessary landscape designs are ignored, and also the important role of water landscapes in improving the urban overall image and meeting the peoples requirements on high-quality life has not been recogni
31、zed. Generally, water landscapes feature operational economical efficiency, water ecology, technical feasibility and water security. Thus, it is necessary to attach high importance to enhancing some necessary water landscape designs in the municipal water supply and drainage design. 4 Problems Neces
32、sary to Notice in the Municipal Water Supply and Drainage Design There are a great number of problems in the municipal water supply and drainage design. It is necessary for us to take measures for preventing and solving these problems. Also, in the municipal water supply and drainage design, it is a
33、lso necessary to pay attention to some problems. If those problems can be seen, the author believes that the municipal water 9supply and drainage design will get increasingly more normative and perfect in China. The problems necessary to notice in the municipal water supply and drainage design can b
34、e mainly reflected from the several aspects below. 4.1 Paying Attention to the Design of Urban Water Supply System The design of water supply pipes network is an important link of water drainage plan and design. The basic steps of designing water supply pipes network are as follows: set road informa
35、tion, lay water supply nodes, place water supply pipes, and draw graphics. According to these requirements, design units make an adjustment to relevant water supply engineering design in accordance with the design of related roads. 4.2 Paying Attention to the Design of Urban Water Drainage System Wa
36、ter drainage mainly refers to collecting sewage from life and production and then draining away them after processing, as well as collecting and draining away atmospheric precipitation and controlling flood and draining flooded fields. The planning and designing of rainwater drainage should be condu
37、cted after a comprehensive consideration given to the 10urban actual previous rainfall, flood discharge areas, storm strength formula and related factors. The design of the sewage pipes network is necessary to transmit road design results and ground line information to the sewage design system; the
38、design of the sewage well is necessary to refer to the given road centerline and lay sewage well along road according to the pile numbers and partial distances specified by the designing personnel; the design of the urban drainage system is also necessary to pay attention to the calculation of waste
39、water. The calculation of wastewater includes the calculations of sewage pipes network and drainage areas. In the calculation, the gradients and pipe diameters are determined using the graphics measurement method provided by the drainage system, so as to help the designing personnel make a right cho
40、ice. The gradients and pipe diameters of sewages drainage are determined according to the results of sewage calculation, and the elevation is automatically calculated by the system. It is necessary for water drainage pipes to make full use of the advantages in terrain topography, so as to prevent the pipes buried too deeply because of too large pipe diameters. The design of the pipeline vertical system is necessary to
