沉积作用及应力历史对自重应力和沉降的影响

土体的沉积作用和应力历史会影响土体自重应力的确定,也会影响地基最终沉降量的确定。鉴于e-lnp比e-lgp坐标图能更方便、精确地描述线性问题,根据e-lnp坐标图推导沉积作用对成层土、正常固结土、超固结土的自重应力与沉降影响的计算式。用该计算式对昆明滇池国际会展中心部分深厚软土地基的自重应力和最终沉降量进行计算,并用计算结果和不考虑沉积作用及应力历史影响的计算结果进行对比分析,结果表明,沉积作用对深厚软粘土自重应力和最终沉降量计算值的影响非常显著,并且土体厚度越厚、上覆荷载越大,其影响越明显。     

FUZZY DISCERNMENT METHOD FOR WALL CLASSIFICATION IN AIR CONDITION LOAD CALCULATION

The building cold and hot loads calculation method for design-ers is spread and used in our country.There are total 301 kinds of commonwalls and roofs,which are classified as 6 types respectively.The cold loadtemperature tables are compiled for designers.With the development of build-ing science,there will be many new types of wall construction without classi-fication.This is inconvenient for fhis new calculation method to be spread.Inthis paper,a new method of wall classification is developed according to theprinciple of fuzzy colony discernment.We have got satisfactory result in com-parison with the result gained by load calculation method.This method invo-lves only algebra calculation and comparison calculation,such as taking bigger,taking smaller etc.,so it is simple and easy for designers to use.     

Model Building and Simulation for Subcritical Pressure Boiler

In order to meet the demand of large scale boiler design and operating optimization, this paper establishes the dynamic mathematic model for domestic 600MW subcritical pressure boiler. MMS software is adopted in the whole process from modeling to simulation. This software make process simple and quick. This model is based on modulariza- tion and the comprehensive physical and chemical process in boiler is considered. Simulation result shows that the re- sponses of this model under different disturbance are coincident to mechanics analysis. The simulation result under ste Pdisturbance can be used to analyze unit changes and provide some guide and it also can supply performance reference data to boiler design.     

Earth Pressure on Retaining Structure of Round Deep Foundation Pit in Sand-cobble Soils

In recent years, the round deep foundation pits engineering gradually appears in Chengdu Plain whose strata are mainly sand-cobble soils. However, there are no proper calculation methods of earth pressure in retaining structure like this and distribution mode of the pressure is unknown. With the use of elastoplastic numerical simulation method involved in interaction between retaining piles and soil, the distribution law of earth pressure of the round deep foundation pit retaining structure is determined. The result shows that distribution of earth pressure on a pile is triangular and the maximum lies in the location of pit bottom, but the average value of the pressure is less than Rankine active earth pressure. Model tests have also been carried out so as to verify the distribution mode. As for the test model, the values obtained by the numerical simulation method are approximately similar to the experimental results in the distribution law as a whole, which to some degree suggests the rationality of the numerical simulation results.     

A CALCULATION METHOD FOR REDUCING WETGHING TIME

This paper discusses a calculation method which can be used to increase the measuring speed of weihging system for products. The usual measuring method can only get exact value after the value has been stable, whereas the method discussed in this paper uses a limited number of transient value obtained during measuring time to calculate the stable value. Simulation result shows that the measuring time can be reduce to about one third.     

Estimation of Earth Work Volume and Design Elevation in Large Earth Work

In this paper,the approximation calculation method based on calculation model of earthwork formula of tetragonal prism is described. The optimization design elevation in large earthwork can be determined by this method. Through introducing a set of different design elevations, the difference between and sum of the total excavation and the total fill can be calculated. An economical analysis is carried out on the design elevation chosen with little value for both cases by numerical values comparison. The elevation with the lowest cost is taken as the optimal design elevation.     

Energy-momentum Tensor of Electromagnetic Field Outside Neutron Star With Magnetic Moment

The energy-momentum tensor of electromagnetic field outside the neutron star with magnetic moment is cal-cuated based on the metric tensor and 4-dimmensioal potential outside the spherical symmetric mass with magnetic moment. The numerical calculation and the distributed curve indicate that the electromagnetic energy of the magnetic-dipole will be greater in curved space-time than in Minkowski space-time.     

Deformation Capacity of FRP Confined Reinforced Concrete Circular Columns under Simulated Seismic Loading

The accurate calculation of the deformation capacity of structures is very important to performance-based seismic design, which satisfies the explicit deformation demands. The method to evaluate drift capacity of fiber reinforced polymer (FRP) confined reinforced concrete circular columns under simulated seismic loading is focused. Firstly, the moment-curvature relationship of FRP confined sections of reinforced concrete (RC) circular columns is simulated by numerical analysis. It is found that the calculated ultimate curvature is significantly less than the test result, and the difference is controlled by the axial load ratio of the tested columns. According to the numerical and the test results, an equation is proposed to modify the calculated ultimate curvature. Based on this, the drift capacity can be predicted with the equivalent plastic hinge method. The calculated result agrees well with the test result when FRP amount is low, but it is significantly larger when FRP amount increases. Finally, the main parameters exerting influences on the drift capacity of the FRP-confined RC circular column are analyzed.     

Method of Measuring the Thickness of Nano-scale Thin Film

A method is proposed to measure the thickness of nano-scale thin film. Based on the differences about mechanical property between the film and the base, a required scratching will be obtained with the proper tool scratching the film directly, which is through the film touching the base and without any effects to the surface of the base. Scanning the scratching area by using atomic force microscope, some data will be obtained and the average thickness of nano-scale thin film can be calculated in the scratching area. The thickness of the TiO2 nano-scale thin film was measured by this method, the experiment result showed that the average thickness of the film is 71.6 nm, which is consistent with the reported result of the reference. This method has high measuring precision, wider application area, more intuitive images, simpler calculation and operation.     

Auto Mesh Algorithm of the Finite Cover System in the Numerical Manifold Method

A auto mesh algorithm of the finite cover system is presented by abstracting the finite cover system of numerical manifold method as independent data classes.The programs are made by Object Oriented Programming(OOP).The accuracy manifold element can be generated automatically when the continuous material is cut by crack.The calculation result shows that the algorithm is reliable and effective.     

A NEN METHOD OF USING VECTOR-MATRIX TO SOLVING A DIMENSIONAL CHAIN IN PLANE

In this paper,a new method of using vector-matrix tosolving a dimensional chain in plane is presented.A mathematical modelis established by means of Rodrig's formula,and the computer programof this method is provided.It is more general and convenient than thegeometric calculation.The numerical calculation is presented in connec-tion with a practical example.The result is the same as that of geometricmethod.     

Influence of Backfill Air Gap on Soil Temperature Recovery in Ground coupled Heat Pumps

Air gap may easily emerge in the progress of backfill in ground heat exchange due to field operation problems. The single U tube three dimensional numerical heat transfer model is set up and there are 3 kinds of backfill air gap assumptions for computational analysis, which are the most common situations in practical projects. Different air gap situations will have considerable effects on soil heat transfer, especially the factor of soil temperature recovery performance, which is investigated in this research, and there is practical project operating data for the comparison confirmation with the theoretical calculation results in inlet and outlet water temperatures. It can be concluded that the backfill air gap will increase the soil average excess temperature in the period of recovery inside the place where the air gap is, and degrade the heat transfer performance of the ground heat exchange.     

Algorithm of Cutter Machining Position during Numerical Controlled Last Carving

Numerical control last making machine is a machine that is used to process shoe last. A new principle of numerical control machining shoe last is put forward aiming at the deficiency of current carving last system. On the basis of the principle, the algorithm of cutter machining position during numerical controlled carving last is analyzed in detail. The complex problem of the calculation of cutter machining positiion is resolved by applying spherical milling cutter that is often used in machining free_curve surface today and taking account of practical situation of the shoe last_making machine. At the same time, the calculation of cutter machining position is realized by program using Visual C++6.0. As a result, the calculation time of cutter machining position is reduced greatly and the efficiency of design is improved. Moreover, the process of carving last is agile and precision of carving last is ensured.     

Load Forecasting Based on BP ANN for Economical Operation of Electric Boiler with Heat Reservoir Under Time-sharing price

Along with the generalization of DSM and time-sharing price system, the use of electric boiler with heat reservoir becomes more and more extensive. Load forecasting of heat supply system is an important base in the study of economical operation of electric boiler with heat reservoir under time-sharing price. The BP ANN modeling of the load forecasting for a 1200 kW electric boiler is discussed. The result of hourly heat load forecasting accords well with the real heat load.     

Solution for One-Dimensional Contaminant Diffusion in Layered Clayey Soils Using Laplace Transforms

Contaminant diffusion in layered soil is very complex. The diffusion process is simplified as a one-dimensional diffusion mode. The Laplace transformation and Laplace numerical inverse transformation are adopted. The proposed solution can be degraded to a single layer case. The obtained results are well consistent with those obtained by the classic theory. The correctness of the presented solution is verified by comparing the calculation results with the results generated by existing numerical software. One case study is conducted and the calculation results have a good agreement with measured data, which prove the reliability of the proposed method. The presented method can be used to solve more complex boundary conditions of contaminant migration.     

The Approximate Method of Quadratic Function With Mixed Constraint

A reduced method to solve the problem with equality constraints is given. Based on the reference we use nonlinear equality constraints, the approximate algorithm is obtained. The nonlinear programming of quadratic function with equality and unequality constraints is discussed by Wang kairong. We transform unequality constraints into equality constraints by add to relaxation variable, the quadratic programming is obtained by linear approximation, and approximate calculation is done by means of reduced method. The result of numerical calculation shows the method is feasible.     

Lagged Surface Collapse Mechanism of Shield Construction in Sandy Pebble Stratum

As for many lagged surface collapse cases that shield crosses the sandy cobble stratum in Chengdu metro No.1 and 2 lines, lagged surface collapse mechanism in sandy pebble stratum was studied. Conditions of engineering geology about sandy cobble stratum were analyzed. Mechanical behavior of sandy pebble was obtained via large-scale tri-axial test. Discrete element method was adopted for numerical computation on lagged surface collapse mechanism. According to the tri-axial numerical test method, the relation between the micro parameters and macro parameters of the sandy pebble stratum layer in Chengdu was calibrated. The face failure of shield tunneling and upward movement of cavity was simulated by numerical calculation. When supporting pressure is small, the particles with the displacement of over 0.1 m have low contact force. The porosity of earth in the region becomes larger and its mechanical behavior becomes worse. Therefore the region can be identified as instability region. Cavity in the ground will be caused after shield tunneling. Soil arching effect is obvious under shield construction. Even though there is cavity in the ground, surface collapse will not bring about immediately. This is important reason for lagged surface collapse phenomena of shield construction in sandy pebble stratum.     

Energy-saving Analysis of Boiler''s Periodic-running

When the technique of "boiler Sultry pressure running" is applied, because boiler's efficiency raises by promoting running parameters up to the designed values, boiler's periodic running is brought forward for the high output and low load situation. By using the positive balance method, the paper is devoted to a discussion on the period running of the boiler to save energy. Relations among energy saving, boiler's running time, standing by time and time ratio are discussed in detail. In addition, the periodic running of the boiler will save the labor of the workers.     

The Distribution of Piezometric Head along Wedge-shaped Fractures

Rock masses have defects,such as joints and fractures, which are the main seepage passages.Joints and fractures often are treated as parallel plates with the seepage state kept steady and the ground stress constant. When changes take place in joints and fractures as a result of stress changes induced by excavation,joints or fractures may be wedge-shaped,and the distribution of piezometric head along the fracture will be nonlinear.A distribution function of piezometric head is suggested and compared with the results of previous research.The influence of this function on the calculation of the slope safety factor is investigated.The study shows that this function is reasonable.