Abstract: As construction industrialization is springing up in our country, precast concrete frame structure,as a result,has been developing rapidly. Based on a host of articles about precast concrete frame structure system at home and abroad,it,in this paper,summarized and prospected the latest stress performance research of precast concrete frame structure and up-to-date engineering application. Further more, total assembled node and seismic behavior of precast concrete frame structure is also pointed out as what is needed to study in the future.
Abstract: Fire resistant behavior is one the main properties of shield tunnel segment in civil engineering. The main objective is to study the regularity of temperature distribution and deflection of shield tunnel segment after fire and the residual bearing capacity after cooling in this paper. According to the tests, a temperature-position fitting curve can be obtained, and it can be obtained that the damaged depth of segment is 7.8cm while heating in RABT curve for 125min. It is found that the residual bearing capacity of segment decrease with the increase of the pre-load, which drops rapidly for it is only about 20% compared to the reference one.
Abstract: The pyrolysis kinetics properties of three kinds of woods, pinus koraiensis, hemlock and spruce, which were taken from the ancient building, the Potala Palace in Lhasa of China, were investigated by using thermogravimetric analysis method. And the Kissinger method was applied to calculate the degradation activation energy of the lignin of these three kinds of wood. The degradation activation energy of the lignin in pinus koraiensis, hemlock and spruce woods was 218kJ/mol, 146kJ/mol and 188kJ/mol, respectively, which showed that the degradation order from hard to easy for these three kinds of wood was pinus koraiensis, spruce and hemlock.
Abstract: The paper analyzed the sulfur in steel for civil engineering in 150t converter in TangSteel. Based on the analysis of desulfurization process and the thermodynamic conditions in converter, the operation of desulfurization was optimized. The industrial tests for desulfurization were carried out, and the results were analyzed. The results were shown that the distribution coefficient would be the highest value, when the alkalinity of slag was 3.5 and the FeO content was 21% in making SPHD steel. The distribution coefficient would reduce, when the temperature was increased, especially more than 1700°C, so end point temperature should be best less than 1700°C.
Abstract: The poor engineering properties of peaty soil are unfavourable for engineering construction. Based on field test datum, the mechanical properties of peaty soil in different buried depth have been analyzed. The result shows that the shear strength of shallowly buried peaty soil reduce gradually with the increase of burial depth, however, which increase gradually along with the depth for deep buried peaty soil. The factors affecting the meso-structure of soil, for example, stress state, the stress history, the stress path, the variation of groundwater, chemical field, biological field and physical field is discussed.
Abstract: Manual arc welding is widely used in all kinds of welding material in the civil engineering because of their stable performance characteristics. Based on the analysis of the incision morphology, microstructure and hardness distribution of different kinds of welding joints by manual arc welding methods, how the different welding method of hot rolling ribbed rebar influenced on the performance of the organization has been emphatically discussed to further optimize its performance and provides theoretical basis for the process. The experimental results show that due to the different welding methods and the different heat input, the macro morphology of each welding joints are not identical. The microstructure of welding joints are mainly formed by proeutectoid ferrite, low carbon martensite, tempered sorbite, fine grain ferrite and pearlite. Different welding method, the vickers hardness values along the axis direction of the welded joint and along the direction of cross section are also not identical, and all these lead to the different performance of the different welding joints.
Abstract: The data of soil moisture in layer of 0-50cm, precipitation, temperature, sunshine hours and cloudiness in 2011 in Gaoyao were analyzed. The results showed that the soil moisture was vertical uniformly distributed in Gaoyao. The soil humidity was larger in an overcast day than in the others. It was relatively smaller in a sunny day than in the others, because of the impact of solar radiation and temperature on soil moisture. Three layer soil moisture variations were almost synchronous, but the variation amplitude of soil moisture in 0-10cm layer was biggest, and 30-50cm soil moisture variation was least. Regression analysis showed that, precipitation and cloudiness played a dominant role on soil moisture variation, while temperature and sunshine had little effect on the soil moisture. Analysis of soil moisture characteristics with the application of soil was useful to civil engineering in Gaoyao.
Abstract: The aim of the present study is to clarify the actual conditions of indoor thermal environment with building materials, which built after 1980 years in urban areas of Zhejiang Province. In this paper, the investigations about building characteristics and indoor thermal environment were carried out in Hangjiahu Plain, Zhenan hills and mountains etc. The results show that the wall materials of the most residential buildings are clay solid bricks, the most windows type is aluminum alloy, and the most buildings are uninsulated. In summer, over half of the air- conditions operate more than 6 hours in residential buildings. The indoor thermal comfort is strongly affected by thermal performance of windows.
Abstract: SAP2000 structural analysis software is used to designed two of 500kV partially prestressed reactive powder concrete pole cross arm; moreover, poles of the two cross arm program have been compared. The results show that the triangular truss cross arm has good mechanical properties, improving the main mate’rial of the stress state, the pole reduced height 10m, by the analysis of the structure shows, this cross arm has higher reliability under the operating conditions, which can be used in 500kV transmission line; from economic and technical performance, the pole cost of this program is greatly reduced, while speeding up the construction progress and improving the comprehensive benefits of the poles in the transmission line.