Abstract: In order to study the supporting structure under different distances between inner pit-in-pit and foundation pit, width and depth of pit-in-pit and general excavation depth of external foundation pit, PLAXIS is adopted to simulate the whole process of pit-in-pit excavation in a foundation pit of Shanghai. The factors which influence wall deflection are analyzed using orthogonal experimental design software. The results show that the factors which influence deformation of pit-in-pit and supporting structure of foundation pit are sorted with range value or sensitivity descending: depth of pit-in-pit, location of pit-in-pit, general excavation depth of external foundation pit, and width of pit-in-pit. Depth and location of pit-in-pit are the most two significant factors, and they have the strongest interactions.
Abstract: The meaning of The Third cosmic velocity is introduced in this paper .recognized value of the third cosmic speed in textbook is 16.7km / s ,then deduced it. To my analysis, noted that the derivation process is open to discussion, put forward my own derivation about The Third cosmic velocity ,the result of the theoretical value is not16.7km / s ,but 13.6km / s.
Abstract: A static triaxial apparatus was designed and manufactured after consideration of shortages in traditional methods for force and deformation measurement. Compositions, structure and functions of this apparatus were introduced. Within this apparatus, an inner force transducer together with digital image processing technology was adopted in order to provide a more accurate measurement of test results. PC functions were modular designed, in order to make the complex processing of interactive features more clearly and easier operation. Finally, results of a typical CD test of saturated sand showed the good performances of this apparatus.
Abstract: The morphological filter as a nonlinear filtering method has been widely used for image (or signal) processing. Unlike the traditional digital filters, mathematical morphological operations are shape-based computing. Feature extraction of signals is entirely in the time domain without the transforming of the signal from the time domain to frequency domain. The vibration signal contaminated with noise is processed using morphological filter and Butterworth filter respectively. To compare the outputs of the two filters, we find that morphological filter shows better performance. It is effective in suppressing noise while maintaining the original signal both in the time and frequency domain. In addition, an outstanding advantage of morphological filter is its ability to keep the phase of the original signal. Its computing speed is faster. In the end, its low-pass characteristic is verified by processing vibration signal.
Abstract: A revised one-dimensional steady model was proposed to improve the prediction of the natural ventilation performance in a solar chimney. The thermal resistance of the glass cover and absorber wall was taken into account to calculate the heat transfer between the air and the glass cover or absorber wall in the model. The present model results were compared to the related experimental data and reasonable agreement was validated. Comparison of the results also showed that the present revised model was able to predict the mean temperature of air in the channel, the air mass rate and heat collection efficiency more preciously than the original model.
Abstract: In the course of city operation and development, the normal state of the river environment encounters hazard of varying degrees, which is manifested in the ecological degradation, functional disorder, and cultural deficiencies. The author elaborated the synergestic effect of Multi-objective Approach (MOA) in the overll improvement of the urban water systems in terms of the ecological restoration, mutiple functions and cultural effecacy. Based on the study of the landscape planning of the open space of the Guohe River in Bozhou City, which made the comprehensive analysis from an ecological, functional, and cultural perspectives and employed the multi-objective landscape remediation and conservation design, we explore the landscape planning methods of the urban waterfront which incorporate the ecology, function and culture of the region to be designed.
Abstract: Schedule, cost, and quality are three main elements to describe the situation of a project’s execution. The improved model, which is based on the tradition EV model, quotes the definition of quality cost and combines the cost, progress and quality, then forms the quality earned value system and the coordinate coefficient of quality and progress. The developed model and the coordinate coefficient, which are on basis of quality cost, make up the deficiencies of traditional EV in terms of quality management. They provide a new method to describe and analyze the situation of the project’s execution systemic, scientific and exactly.
Abstract: In order to deeply understand the present situation and the main influence factors of Chinese railway survey and design market, the questionnaire investigation was conducted. The descriptive statistics analysis, frequency analysis, correlation analysis and factor analysis have been adopted in data analysis. The results show that the quality level of Chinese railway survey and design can not meet the need of railway construction. The main problems includes: dragging delivery of design documents, poor service quality of site design, inaccuracy of geological data, and inaccuracy of construction quantity. The main cause is the absence of effective incentive and constraint mechanism.
Abstract: Dam safety monitoring data can be viewed as a digital signal sequence which consists of different frequency components. Identifying outliers to ensure the reliability of observational data becomes a foundation work of dam monitoring data analysis. Outliers of time signal series can be detected by wavelet transform. Lipschitz index can be used to measure the local singularity of a function, and the original abnormal signal can be found in the position of wavelet transform modulus maxima. Take horizontal displacement values observed by Lijiaxia concrete dam as example, an assumed error are added to the time series signal deliberately. A 4-level decomposition of the observation data was done by using wavelet db1, the results show that the modulus maxima occur at the given time. Therefore, outliers can be detected and located accurately by wavelet transform, which is important to analyze the safety monitoring data of dam.