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In this study, numerical simulation of anchor bolt pullout in plain concrete by a heterogeneous numerical model is presented. The heterogeneity of the concrete material was modeled by randomly assigning strength and elastic modulus to the elements according to Weibull's distribution. The ongoing debonding process was obtained, including crack initiation, crack propagation and formation of the concrete cone. The numerical results indicate that there is a strong size effect on failure resistance of the concrete cone. By increasing the anchor head size, peak pullout load and the volume of concrete cone increase. The peak pullout load and the volume of concrete cone also increase with the increasing of embedded length. With this heterogeneous numerical model, the asymmetrical crack patterns and the crack branching observed in tests is obtained. Moreover, asymmetrical crack and crack branching were easy to occur with lower homogeneity index. The numerical results agreed well with the experimental investigations.

Abstract With the annual growth of development scale and production, the research of heavy oil and oil sands become more and more important. Due to the characteristics of heavy oil and oil sands, the degree of reserves recovery is restricted by development mode. So there is a big difference in classification criterions and evaluation techniques of reserves in the world. In this paper, using the major heavy oil and oil sands accumulation areas —Venezuela heavy oil belt and Canada oil sands as example, we analyse the reservoir characteristic of heavy oil and oil sands, and then discuss the classification and evaluation techniques of reserves suitable for different development modes. The heavy oil belt in Venezuela and oil sands in Canada are all characterized by huge thickness, middle-fine sandstone, loose cementation, high porosity and high permeability. To adapt different development mode, we establish corresponding evaluation criterions for reservoir, including porosity, permeability, shale content, saturation, barrier and interbed, the thickness and width of continuous oil layer and so on. We classify the reserves as OOIP, economic reserves, reserves for horizontal well, reserves for steam flooding (SF)/ cyclic steam stimulation (CSS) and reserves for SAGD. Using logging and geophysical techniques, we evaluate and classify the reserves. 1.Introduction Heavy oil and oil sands are characterized by shallow buried depth, large thickness, huge reserves and unconsolidated structures. Because crude oil has high viscosity, conventional vertical wells generally have no or extremely low productivity. Currently, these reservoirs are predominantly developed by horizontal wells in two stages: cold production and thermal production. All these conditions have presented new requirements on contents and methods of reserve evaluation. In this essay, through study on reservoir features and corresponding development techniques for heavy oil in Venezuela and oil sands in Canada, we put forward reserve assessment methods and techniques by class for various development modes. 2.Reservoir evaluation and selection criteria for heavy oil and oil sands development Currently, cold production (CP) is the prevailing development method adopted for heavy oil in Venezuela, at the same time, cyclic steam stimulation (CSS), steam flooding (SF) and SAGD have been tested. Oil sands in Canada are mostly developed by SAGD and open mining. A series of reservoir selection criteria have been proposed to cope with requirements of different development methods with horizontal wells on oil layers (Table 1).

In modern industries, the lack of accurate real-time energy monitoring will lead to energy waste. To address this issue, we propose an effective, reliable and low-cost solution. Our scheme uses XBee-Pro S2 for communications, and provides user-friendly application software based on WPF and controls of NetAdvantage. The application of high performance XBee-Pro S2 modules solves the defects of the traditional ZigBee networks with short transmission distance and week anti-jamming ability. The WPF framework employed in this work leads to enhancement on the UI, the development efficiency, and the reliability of the monitoring software. System testing shows that the operation of the network is stable and the transmission of data is reliable.