Abstract: The tunnel foundations treatment is the key and difficult point of the research of the tunnel in collapsible loess areas. The characteristics and advantages of the common foundations treatment technology for tunnels of loess areas are summarized in this paper, at the same time, the characteristics of a new technology for the non-vibration compaction treatment technology developed by the Northwest Research Institute Co., Ltd. of China Railway Engineering Corporation are introduced, which is suitable for the foundation reinforcement treatment of the tunnel in collapsible loess areas. Through the field experiment of base treatment of high-speed railway tunnel of the Baoji–Lanzhou High-Speed Railway Passenger Dedicated Line, it is demonstrated that the new non-vibration compaction machine has the advantages of convenient movement, controllable treatment effect, miniaturization, low cost and so on. The advancement and maneuverability are verified from the soil compaction coefficient between piles and the change law of collapsibility of the soil between piles under the different pile spacing conditions. The research results can provide new techniques and methods for the foundation reinforcement treatment of the tunnel of small space, strictly controlling construction vibration in collapsible loess areas.Abstract: The tunnel foundations treatment is the key and difficult point of the research of the tunnel in collapsible loess areas. The characteristics and advantages of the common foundations treatment technology for tunnels of loess areas are summarized in this paper, at the same time, the characteristics of a new technology for the non-vibration compactio...Show More
Abstract: The use of metallic oxides in enhanced oil recovery in the initial stage seems to significantly enhance the productivity from a well by increasing the sweep efficiency, reduce interfacial tension, and reduce oil viscosity among other factors. However, in later stages of the life of the reservoir, it is observed that the technology brings adverse effects such as reduction in the permeability of the reservoir rock, which may cause decline in production and may lead to the abandonment of the reservoir, although there may be sufficient underlying hydrocarbon. This paper studies the extent of permeability alteration due to the aluminium oxide nano-powder, the total amount of recovery due to aluminium oxide nano-powder. It also compares the performance of aluminium oxide nano powder with other selected nano powders, which are silicon oxide and magnesium oxide. In the experiment, the Core Flooding System was used to simulate reservoir fluid flow in the constructed sand packs. The Enhanced Oil Recovery percentages as well as permeability changes were obtained. From the results, in comparison with traditional water flooding, aluminium oxide as well as silicon oxide and magnesium oxide gave high increase in recovery. However, aluminium produced the greatest recovery increase. A higher permeability change was given by aluminium oxide at higher concentration, while at lower concentration, aluminium oxide gave a lower permeability change.Abstract: The use of metallic oxides in enhanced oil recovery in the initial stage seems to significantly enhance the productivity from a well by increasing the sweep efficiency, reduce interfacial tension, and reduce oil viscosity among other factors. However, in later stages of the life of the reservoir, it is observed that the technology brings adverse ef...Show More