02907cam a2200337 a 4500 EG-GiCUC 20250223032653.0 210110s2020 ua dho f m 000 0 eng d EG-GiCUC eng EG-GiCUC eng Deposite M.Sc Cai01.13.05.M.Sc.2020.Om.A Omar Badr Mohamed Badr Appropriate drain envelope for problematic calcareous soils in Egypt / Omar Badr Mohamed Badr ; Supervised Abdallah S. Bazaraa , Gehan A.H. Sallam اختيار مغلف مواسير الصرف المناسب للتربات الكلسية الاشكالية بمصر Cairo : Omar Badr Mohamed Badr , 2020 101 P . : charts , facsmilies , photographs ; 30cm Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Civil Engineering Agricultural subsurface drainage systems are commonly used to remove the excess water and salts from the root zone to enhance crop production and to ensure irrigated agriculture sustainability. In Egypt, drain pipes installed in soils with limited cohesion (clay content is less than 30%) should be provided with envelopes to prevent the entry of soil particles into the drains (filter function) and to reduce entrance resistance by creating a more permeable zone around drains (hydraulic function). Calcareous soils with calcium carbonate (CaCO3) content of more than 15% are considered hazardous problematic soils that cause envelope clogging and sedimentation in the subsurface drainage network. Earlier testing of synthetic drain envelopes in Egyptian calcareous soils has revealed poor performance. Therefore, the main objective of this study is to determine the most appropriate locally available envelope material(s) that can be used in calcareous soils under Egyptian conditions. Both theoretical and experimental (laboratory as well as field) investigations were conducted to assess the performance of the locally available synthetic envelope (polypropylene with pore size 400 microns {u2013} PP400) alone and combined with granular materials. The assessment results (theoretical and experimental) indicated that the currently used synthetic envelope PP400 is not performing well when used alone (too thin with low porosity). Treatments that have a gravel material, either alone or in combination with the locally available synthetic envelope revealed good performance and consequently gravel envelopes alone are recommended Issued also as CD Calcareous soils Envelope materials Subsurface drainage Abdallah S. Bazaraa , Supervisor Gehan A.H. Sallam , Supervisor http://172.23.153.220/th.pdf Amira Cataloger Nazla Revisor ddc TH 79514 79514 ddc 0 CUCL cl210 2024-02-11 Cai01.13.05.M.Sc.2020.Om.A 01010110082479000 2023-09-22 00:00:00 TH ddc 0 CUCL cl2u8 2024-02-11 Cai01.13.05.M.Sc.2020.Om.A 01020110082479000 2023-09-22 00:00:00 82479.CD CD