Subsidence, soil suffusion and their influence on the appearance of cracks on concrete slopes of irrigation canals

¹ "Tashkent Institute of Irrigation and Agricultural Mechanization Engineers" National Research University, Tashkent, Uzbekistan
² Consultant Engineer for the Proj. improvement of Water Resources Management in South Karakalpakstan, Uzbekistan
³ Taraz Regional University named after M.Kh. Dulaty, Taraz, Kazakhstan

^* Corresponding author: bakiev1947@rambler.ru

Abstract

The physical and physical-mechanical properties of soils, exceeding permissible hydraulic gradients, rapid filling and emptying of canals, the quality of embankments, linings and others which determine the filtration stability of canals. After completion of construction in the western part at PK47+20, PK202+80, PK218+00, longitudinal cracks appeared in the left slopes. To identify the causes of crack formation, the concrete lining was removed and comprehensive study for the causes of cracks was carried out. Based on the plasticity number, the soils were classified as sandy loams and loamy. The relative subsidence deformation for samples taken from PK 202+80, 218+00 and one sample from PK 47+20 are less than 0.007, those are not subsidence, but the results of second sample taken from PK 47+20 showed from 0.014 to 0.017 which is subsidence soil. The results for the analysis of water samples show the turbidity at PK 185+00 and 218+00, results are 128 mg/dm3 and 11.5 mg/dm3 which exceeds the 6 times than norm, and the results of dry residue are 2026 mg/dm3 and 2030 mg/dm3, which exceed 2 times than the norm.