Choosing a technology for repairing sewers operated in difficult soil conditions with account of the geometric irregularity of the tunnel sections

Summary

Long-running sewer tunnels in large cities have a degree of deterioration of up to 55% or more. Difficult engineering-geological and hydrogeological conditions for tunnel laying, as well as intense anthropogenic impacts cause an increase in the defect rate of sewer tunnels. Based on calculations and hydraulic modeling, it is shown that with a high load of sewer tunnel networks and the impossibility to stop completely the transportation of effluents, the primary objective in choosing measures for repair and rehabilitation of tunnels is the search for technical solutions that provide for the maximum wastewater flow after the rehabilitation given the cross-section narrowing and geometrically irregular sections. The successful experience of SUE «Vodokanal of St. Petersburg» in the rehabilitation of sewers with narrowing sections without stopping the transportation of wastewater using technologies that meet these requirements is presented.

Key words

discharge capacity , operation reliability , sewer tunnel , complicated ground conditions , vibration strength , subsidence , cross-section narrowing , repair technology

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The appraisal of the technical state and operation reliability of waterworks

Summary

The results of evaluating the technical condition and reliability of waterworks carried out by NII VODGEO OJSC Center of Expertise are presented. Most typical violations and drawbacks revealed during the expert appraisal of the safety statements of the waterworks technical state and operating conditions are identified. The lack of monitoring the environmental impact of waterworks is particularly noted. A set of actions on eliminating the revealed drawbacks and improving the safety level of waterworks is suggested.

Key words

waterworks , safety technique , operation reliability , safety monitoring , emergency situation , safety statement expertise

Pipeline integrity and evaluation of the water distribution network reliability in Iraq cities

Summary

The results of evaluating the integrity of water distribution networks in Iraq cities are presented. It is shown that under conditions of limited economic opportunities, material and technical resources the program of upgrading the networks shall be optimized with the use of reliability indices and correction of dates and methods of implementing the action plan.

Key words

water supply , operation reliability , pipeline damages