Applied Mechanics and Materials Vols. 94-96

Abstract: The Guangzhou New TV Tower with a total height of 610 m is the tallest tower in the word. It comprises a 454 m high main tower and a 156 m high antenna mast. The main tower is a tube-in-tube structure consisting of a steel lattice outer structure and a reinforced concrete inner structure. The antenna mast is a steel structure founded on the tope of the main tower. To ensure the safety during construction of this challenging structure, the failure probability estimates under wind load during construction has been performed. The estimates consists of three steps. First, the cumulative distribution functions (CDFs) of static wing loads per year at Guangzhou site are given out. Secondly, the CDFs of horizontal displacement responses during construction of the Guangzhou New TV Tower to static wind loads are derived based on static analyses of a reduced finite element (FE) model of the structure. Finally, anti-wind safeties during construction of the structure are estimated based on the structural reliability method. The study not only provides useful data concerning the structural safety of the Guangzhou New TV Tower during construction but also is of considerable referential importance in estimating the safety of an in-construction supertall structure.

Abstract: Green construction is the main reflection of the sustainable development strategy in the application of engineering construction, and the important composition of Sustainable building industry. This article takes the green construction scheme design as object of study, summarizes the present situation and the shortage of green construction scheme design in China, and makes a certain degree of analysis. Through the research on the green construction management implementation, the design principle and the overall framework of the green construction scheme is determined by raising the green construction consciousness, solving economic security, establishing and perfecting the legal system of rules and regulations, evaluation system, and regulate the green design framework of content, promote the concrete implementation of green construction.

Abstract: Due to release and accumulation of industrial contaminants in natural soil in some regions, and the long-term interaction between leachate and clay which is adopted as isolation material of contaminants, the engineering property variation of clay soils after having been polluted by heavy metal ions gradually has drawn more and more attention of environmental geotechnical engineers. With relatively high chemical stability and low expansion coefficient kaolinite is widely distributed and usually used in engineering practice. In this research, Pb, Zn, and Cu-contaminated kaolinite specimens of controlled initial dry density and water content were manually prepared through static compaction. Then expansion capacity, unconfined compression, electrical resistivity and one-dimensional consolidation tests were conducted. It is found that the expansion capacity of contaminated kaolinite is influenced by the type and concentration of heavy metal ion. The unconfined compressive strength of heavy metal-contaminated kaolinite is decreased in a short period, but it may increase in a long term. Unconfined compressive strength of the same type of heavy metal-contaminated kaolinite will change with the contamination concentration. The electrical resistivity of kaolinite would be decreased when contaminated by heavy metal ions. The higher the contamination concentration is, the lower the electrical resistivity will be. All the compression indexes of heavy metal-contaminated kaolinite become lower than that of the clean kaolinite, and it also depends on both the type of heavy metal and contamination concentration. For the three types of heavy metal ions, Pb has the greatest influence on the engineering property of kaolinite, while the effects of Zn and Cu are quite similar.

Abstract: A mathematical model for the soil-water characteristic curve is proposed in the light of bounding surface plasticity. The main drying and wetting curves are taken as the asymptotes of the scanning curves, and only one additional parameter is introduced to simulate such scanning curves. To pave to the way for the application of the proposed model, the governing equation of unsaturated seepage problems and the finite element formulations are derived. A FEM program incorporating the SWCC model is then developed and used to study the hydraulic behaviour of an earth dam undergoes a repeated change of reservoir level. Numerical results confirm the possibility and necessity of using such a hysteresis model in unsaturated seepage problems.

Abstract: Based on the achieved engineering practice results of deep roadway drivage in Xinwen Mining Area, aimed at drivage problem of deep cross-level coal-rock, EBZ-135 fully-excavating machine had been used to replace traditional roadway blasting drivage, corresponding key technology of fast supporting for deep large sections of coal-rock roadway in high stress had been proposed, and latter mating transport system transformation of fully-mechanized fast drivage technology had been cooperated, which formed a suit of fully-mechanized fast drivage technology for deep large sections of coal-rock roadway in high stress. The application results show that the fully-mechanized fast drivage technology can markedly enhance the whole shaping quality of roadway, improve drivage efficiency and cycling footage immensely, reduce roadway drivage cost, and the good result of average month footage at 300 m and maximum month footage at 360 m have been achieved finally.

Abstract: Elasto-plastic analysis of seismic responses of valve hall structures were carried out by using finite element software, and the effect of seismic waves on the seismic responses of the valve hall structures and suspension equipments were studied. Results show that significant torsional responses of the structure can be found under longitudinal and 3D earthquake actions. Under 3D earthquake actions, the seismic responses of the suspension valves are much more significant than those under 1D earthquake actions, the maximum tensile force of the suspenders is about twice of that under 1D action. The seismic responses of the suspension valves under vertical earthquake actions are much stronger than those under horizontal earthquake actions, when suffering strong earthquake actions; the maximum vertical acceleration of the suspension valves is about 4 times of that under horizontal earthquake actions. It is recommended that the effects of 3D earthquake actions on the structure should be considered in seismic response analysis of the valve hall structure.

Abstract: Filling pile is a common form of pile foundation work, it passes the superstructure loads to the deep stabilitily soil or rock , reducing the non-uniform settlement of ground and foundation. Because of bored piles is done underground, underwater, quality control is difficult. The construction technology and quality control measures of bored pile is been introduced.

Abstract: A remedy scheme of water leakage in the deep foundation pit of a subway station is introduced. The deformation and axial forces of the supporting structure as well as the underground water level were monitored during the leaking prevention process. At the same time, a plane model was developed to simulate the construction process of foundation pit by FEM. Then, the fundamental reason for the leaking of the foundation pit was analyzed by numerical results and in situ measured data. Furthermore, importance of the strength of the supporting structure to the excavation of the foundation pit was also detailed demonstrated. Finally, the remedy measures were put forward to prevent the water leakage, which were proved to be effective and feasible in practice.

Abstract: An identifier-selection method based on the recognition probability of the expressway network was proposed. Firstly, the probability model of the route network is built through the known information, such as the network topology of the expressway, the traffic flow density and the identifier accuracy. Secondly, the recognition probability of expressway network is calculated based on the recognition probability of the competitive paths. Finally, an identifier-selection method is provided. The results verify the rationality and practicality of the method.

Abstract: In this paper, the work of data acquisition is devided into the horizontal distance and height measurement according to the features of 3D data obtained from ancient building. The non-prism total station is used to achieve the non-damage and non-contact data acquisition from the ancient building. Moreover, the method of 3D reconstruction and digital preservation of ancient building is introduced based on 3DGIS, which has practical value based on its efficiency and reliable accuracy.