Advanced Materials Research Vols. 250-253

Abstract: The plasma in the eolian sand, included silt particle and clay particle, change easily and hugely. For studying their influences on the strength property of eolian sand, mixed silt particles and clay particles in different proportion into the eolian sand to carry out CBR test. The test result indicates that, along with the increase of silt particle and clay particle content the CBR value also increases within a certain range, which indicates the increase of silt particle and clay particle content can firstly improve the gradation of eolian sand; after the gradation is improved can obtain large compaction dry density, and at the same time also can enhance the earth strength, included the CBR value. The range of silt particle and clay particle content made the CBR value increase is also very large: ≤40% when formed under dry state, and ≤45% when formed under optimum or saturated water content; if the water content in forming could be retained at all times, the former could be ≤55% and the latter still ≤45%. The mechanism analysis further indicates that, when there were no excessive silt particles and clay particles, in the large range of silt particles and clay particles changing from small to large, the engineering nature of eolian sand will be improved due to the improvement of gradation, which is advantageous to the extensive application of dry compaction process; but the eolian sand formed by dry compaction is defective on microstructure, and so the requirements for silt particle and clay particle content should be more strict in practical works.

Abstract: The soft base in the testing section of Jiang-zhu highwaysis 55 meters deep, and its mechanical property is not better than that of silt soil, the sand-wick drained length is one of the crucial factors for this highwaywhich influences the consolidation speed. Based on the characteristic of soft foundation, experiences and the interrelationship between the processing area and the subjacent bed effecting on draining, the mechanism of extra-long sand-wick for the extra-deep soft foundation is studied. The theoretical consolidation degree in the deep soft foundation treating with extra-long sand-wick drain had been calculated, the designed depth of sand-wick drain were 25 and 22 meters. Moreover, the total settlement will be predicted. According to the monitoring data of displacement and settlement during loading, the characteristic of consolidation settlement of the soft soil foundation had been analyzed. The results indicated that the settlement was very sensitive to the loading speed. The sedimentation became fast with the increasing loading. The sedimentation speed was always very high, which was 15 to 25mm/day on the average. During the prophase of pre-compaction, the consolidation degree of section K53+242.47 (h=25m) was up to 80% in 350 days, which was much faster than the section K53+402.47 (h=22m). Moreover, the soft soil foundation was consolidated stably according to the strict dynamic monitoring data. By using hyperbolic theory to analyze monitoring data, the predictive settlement value of post-project can meet the designed requirement. The treating effect of the 25m depth sand-wick drain was better than that of 22m, which provided available data for extra thick soft foundation treatment.

Abstract: The solar energy photovoltaic thermal system is a method to achieve grade utilization of solar energy to improve the comprehensive utilization efficiency of energy. A kind of solar energy photovoltaic air conditioning wall is put forward in this paper, adopting the air flow channel with a small hole on the surface and the negative pressure inside, which can provide electricity and hot air heating simultaneously. The comparison test of the solar photovoltaic cells components (PV) and the solar photovoltaic air conditioning wall (PV/T) shows, under the condition that the radiation intensity reaches above 700W/m²，and the ambient temperature exceeds 25°C, the temperature of PV/T components is slightly higher than PV components, so the power generating efficiency decreases slightly, with the average generating efficiency 12.51%, while the efficiency of the PV is 12.96%.each square meter of the solar energy photovoltaic air conditioning wall can provide the building with 40 m³ of fresh air per hour, with 20°C higher than outdoor, so the average photo-thermal efficiency is 39%.If the photovoltaic air conditioning wall is installed on outside surface of the building envelope, or replace it, to built the building integrated photovoltaic solar thermal system, the building energy consumption would greatly reduce.

Abstract: Cushing Library located on Texas A&M University campus is a special building, which needs precise temperature and relative humidity control, because it stores a number of rare collections and memorial books. This paper will concentrate the unit, which serves the book stacks. This AHU is a multiple zone, constant air volume (MZCAV) system, with reheat and direct digital control (DDC). It has a standard cooling coil, glycol cooling coil, steam humidifier, and heat recovery. Because of programming problems and hardware problems, the relative humidity was not controlling properly. In this paper, the new control program for temperature and relative humidity control is implemented and the energy savings from the new control program is estimated.

Abstract: A multi-functional institutional building often has ventilation and comfort requirements that vary widely from zone to zone. When we commissioned the Reed McDonald building on the main campus of Texas A&M University (TAMU), efforts were made to control its environment according to the zone functions so that occupants can be satisfied with the comfort, and provided with a healthy and safe teaching and working environment. This paper presents a case study of the problems encountered and solutions implemented when recommissioning a multi-functional institutional building.

Abstract: Based on the project management with life-cycle management technology, this paper establishes a integrated system of life-cycle management (LCMIS) for large stadium construction project, which integrates decision making, design, construction and operation by two levels of entire life cycle and phrases. It resolves the existed problems of this kind of project, like the limitation of financing model, the disparity between design and construction, operation problems.

Abstract: In the high-rise building, the conversion layer is often set when the structure of upper and lower floors are different. This conversion layer plays the role of transitional connection. But the force is complex, the conversion layer is the weak layer of the structure and it is the difficulties of the structure design and building construction. However, conversion layer has large section size, bulky, complicated structure the temperature stress to generated cracks in long-span beam type conversion layers. In this paper, directed towards the long-span beam type conversion layer characteristics, combined with tempertural stress in mass concrete causes, proposed control points of long-span beam type conversion layer . It has practical directive significance for long-span beam type conversion layer.

Abstract: Considering the characteristics of vision in the low luminance and weak contrast environment, this research obtains a series of simulant scenes. By means of experiment observation, quantification analysis and subjective evaluation, this research proposes a kind of scientific and controllable methods and modes, then relates the quantitative index and the qualitative description in order to take physics and psychological factor into the comprehensive consideration in lighting environment. Finally, it obtains the scope of luminance stimulus and the quantification relations. The results of this research can provide theoretical basis, model and quantitative suggests for corresponding standards. It has significance to urban lighting planning, design and management.

Abstract: The impact of blasting effect is an important factor of dynamic stability in the excavation of rock slope. Based on the sub-grade engineering in Jin-hai Lake of the New Countryside Construction Project, this paper sets up a finite element analysis model for the dynamic response of the cutting slope under the blasting loading. It discusses the stress field, displacement field and the propagation law of the blasting seismic wave, and analyzes the security evaluation criteria of the dynamic stability of cutting slope. What’s more, it makes a systematic analysis on the effects of blasting excavation on the stability of the cutting slope according to blasting vibration monitoring. The research provides referential value to form a correct understanding towards slope damage caused by blasting excavation.

Abstract: To research the suitable water intake technology of open-lakes Water Source Heat Pump system (WSHPs) in Chongqing, water temperature, water quality and other water features of lake and reservoir are analyzed. Results show that the temperature of water source in Chongqing’s lakes and reservoirs excelled the air temperature, and the water quality basically meets the requirements of open-lakes WSHPs. Thus the water source in Chongqing’s lakes and reservoirs is a hot and cold source of good quality. For depth of water is greater than 6m, there is an obvious vertical stratification of water temperature in summer, which is not obvious in winter. pH value, turbidity and algal density also have obvious characteristics in vertical distribution, while hardness and salinity have little characteristics. According to the spatial and temporal distribution features of water temperature and water quality, water intake head should be installed in the middle and lower layer of the lake. Less investment and water head loss, lower operation and maintenance costs, and higher reliability should be considered when we choose the way of water intake for WSHPs in Chongqing. Water intake ways such as pump truck water intake, pontoon intake, gravity pipe intake, integrated device are alternative. Comparison between technical and economic should be made first.