Research and Application of Neutron Detection Technology in Inspection of Void Defects in Turbine Runner Chamber

After a long-term operation of the turbine runner chamber, there may be voids between the steel lining and the concrete. If it is not discovered and treated in time, the safe and stable operation of the unit will be affected. In engineering practice, the hammering method is often used to detect hole defects, and the accuracy is low. The neutron detection technology is proposed to detect the void defects of the steel lining, quantitatively display the void location and size, and improve the accuracy of void defect detection.

Buckling Behavior of Thin-Walled Stainless-Steel Lining Wrapped in Water-Supply Pipe under Negative Pressure

This paper presents a study about the buckling behavior of thin stainless-steel lining (SSL) for trenchless repair of urban water supply networks under negative pressure. The critical buckling pressure and displacement (p–δ) curves, temperature changing curves, hoop and axial strain of the lining monitoring section and the strain changes with system pressure (p–ε) of the lining under the action of different diameters, different lining wall thickness and different ventilation modes were obtained through five groups of full-scale tests. The variation principles of the post-buckling pressure and the reduction regularity of the flowing section of the lining were further investigated. By comparing different pipeline buckling models and introducing thin-shell theory, the buckling model of liner supported by existing pipe was established. The comparison between the test results and thin-shell theory indicates that one of the significances of the enhancement coefficient k value is to change the constraint condition of the aspect ratio, l/R, thus increasing the critical buckling pressure of the lining. Finally, an improved lining buckling prediction model (enhancement model) is presented. A previous test is used as a case study with the results showing that the enhanced model is able to predict critical buckling pressure and lobe-starting amount of the liner, which can provide guidance for trenchless restoration of the liner with thin-walled stainless steel.

Accounting for the Steel Lining Influence on the Results of Solid Rock Resistivity Probe from Development Working Boundary

When solving problems of predicting the hazards of solid rock bump and outburst in development and stope workings, the resistivity probe methods are often used, in particular, the four-probe method, in which electrodes are placed on the roof or the sill of the mine. The presence of steel lining in the mine significantly affects the measurement results until the complete collapse of electric field, so the electrodes are embedded into the rock. To obtain the true value of rock resistivity, it is necessary to make corrections due to the metal lining influence. This paper is devoted to the determination of these correction factors.

Computer Analysis of Thermomechanical State of Sealing Steel Lining for Containment of NPPs with VVER-1000/V-320 in Emergencies

Computer analysis of thermomechanical state of the sealing steel lining under relevant extreme hazards has been performed to define the possibility and scope of loss of integrity of sealing steel lining, in particular the possibility of losing of the confining function by the NPP reactor compartment containment under emergency conditions. The study gave an opportunity to obtain functions of stress strain parameter evolution function in reinforced concrete and sealing steel lining depending on changes in emergency temperature and pressure in the reactor compartment. The paper assessed the margin of sealing steel lining bearing capacity.

DEFINING FIRE AND TECHNICAL CHARACTERISTICS OF A STEEL BEAM WITH CORRUGATED WEB AND ITS COMPLEX LINING

This new technical solution introduced in the paper is related to the area of fi re safety and involves the method of determining required indicators of constructional fi re-proof characteristics of a steel beam with corrugated web which in itself is a composite welded I-beam with large sheet and plate lining. The paper also delivers results of patent research on the problem of steel constructions fi re protection and describes other similar technical solutions. The authors analyze shortcomings of these solutions and their technical level, identify tasks and objectives of their new technical solution and demonstrate technical eff ects of the new technology (such as devices, inventions, utility models). Further in the paper activities and measures to achieve the proper technological eff ect are outlined and application peculiarities of fi re and technical characteristics of the integrated steel lining are indicated. The researchers also stress specifi cs of the I-beam components performance evaluation and put forward new analytical equations to calculate fi re resistance characteristics of steel elements as well as a new methodology for determining geometric and heat-technical characteristics of complex fi re-proof lining. There is also an example of calculations according the developed algorithm given in the paper.