Soil Pressure and Deformation Analysis of Small Size Deep Foundation Pit

In this paper, the influence of space effect on soil pressure and deformation of deep foundation pit was considered, and the finite soil pressure calculation model was established. The soil pressure of deep foundation pit was calculated by assuming the slip surface and using the finite soil limit equilibrium theory. Then, PLAXIS 3D finite element software was used to establish finite element models of different plane sizes and depths. The distribution regulation of side wall soil pressure and deformation of deep foundation pit was calculated. Finally, the results of finite soil pressure calculation was compared with finite element method. The results shown that: The soil pressure of small deep foundation pit was affected by space effect, and the soil pressure and deformation decrease significantly along the foundation pit depth. Shear fracture Angle was related to the ratio of width to depth of foundation pit, and it was no longer a constant value of 45°+φ/2. Therefore, the spatial effect should be considered in the calculation of soil pressure of small deep foundation pit. The research results can provide some guidance for the design and calculation of similar small size deep foundation pit.

Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to produce a graphical user interface (GUI) for MATLAB programs written byJ.S.Marsland as part of his research into the excess noise factor in avalanche photodiodes (APDs). TheGUI will be produced using the GUIDE package supplied with the MATLAB software combined withthe MATLAB programs. The GUI will then be used to compare this research work with the researchwork of others e.g. the Monte Carlo calculations made by the research group at the FrenchAerospace Laboratory (ONERA). Comparison with other research work will require the digitization ofsome graphs published in academic journals.

Sensitivity of the area method with mono isotopic fission chambers to reactivity changes in subcritical nuclear reactors

High-level waste is an important safety issue in the development of nuclear power. A proposed solution is the transmutation of waste in fast reactors. The exclusion of the risk of supercriticality by using subcritical reactors is currently under development. Controlling the subcriticality level in such reactors presents difficulties. A problem is posed by the so-called space effect observed when using in reactors many neutron detectors in different locations of the core and reflector. Reactivity obtained from measurements, for example, by the Sjöstrand method, differs by nonnegligible values. Numerical corrections can partially improve this situation. The use of a monoisotopic fission chamber set, designed for a given reactor, when each chamber is intended for a specific position in the system, can improve the situation. A question arises about the sensitivity of the results to reactivity changes. This issue is analyzed by computer simulation for possible fissionable and fissile nuclides for the total range of control rod insertion, changes in reactor fuel enrichment, and fuel temperature. The tested sensitivity was satisfactory at most levels from several dozen to several hundred pcm. A case study was conducted using the VENUS-F core model.

Structural Dynamic Response of a Shield Tunnel under Aircraft Taxiing Load

Dynamic load is an important factor affecting the safety and stability of subway tunnel structures. To obtain the variation law of shield tunnel structure dynamic response under aircraft taxiing load, a three-dimensional numerical simulation of such tunnel under the action of aircraft taxiing load is performed on the basis of a project involving a shield tunnel orthogonal underpass taxiway. The effects of sliding speed and tunnel depth on the structure of the shield tunnel are also analyzed. The results show that the transverse displacement and acceleration response of tunnel segment exhibit evident time-space effect under the action of aircraft taxiing load. The transverse displacement and arch waist acceleration of the shield segment increase first and then decrease. The transverse displacement of the arch waist reaches its maximum when the aircraft taxis directly above the tunnel. The sliding speed exhibits an evident influence on the dynamic response of shield tunnel structure. The vertical and convergence displacements of tunnel segments increase with the increase in sliding speed. The dynamic response of tunnel structure is significantly affected by the factors of tunnel buried depth. The vertical and convergence displacements of tunnel segments decrease with the increase in tunnel buried depth. Therefore, the safety of the shield tunnel structure can be ensured by controlling the taxiing speed when the aircraft taxis directly above the tunnel. The measures of increasing the buried depth of the tunnel or strengthening the tunnel structure need to be considered when the taxiing speed is large.

Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to develop a graphical user interface (GUI) for MATLAB programs written by J. S. Marsland as part of his research on the excess noise factor in avalanche photodiodes (APDs). The GUI will be developed using the GUIDE package supplied with MATLAB. The GUI will then be used to compare this research with other works—for example, the Monte Carlo calculations performed by the research group at the French Aerospace Laboratory (ONERA). A comparison with other works will require the digitisation of graphs, some of which have been published in academic journals.

Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to develop a graphical user interface(GUI) for MATLAB programs written by J. S. Marsland as part of his research on the excess noise factor in avalanche photodiodes (APDs). The GUI will be developed using the GUIDE package supplied with MATLAB. The GUI will then be used to compare this research with other work —for example, the Monte Carlo calculations performed by the research group at the French Aerospace Laboratory (ONERA). A comparison with other works will require the digitisation of graphs, some of which have been published in academic journals.

Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to produce a graphical user interface (GUI) for MATLAB programs written by J.S.Marsland as part of his research into the excess noise factor in avalanche photodiodes (APDs). The GUI will be produced using the GUIDE package supplied with the MATLAB software combined with the MATLAB programs. The GUI will then be used to compare this research work with the research work of others e.g. the Monte Carlo calculations made by the research group at the French Aerospace Laboratory (ONERA). Comparison with other research work will require the digitization of some graphs published in academic journals.

Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to produce a graphical user interface (GUI) for MATLAB programs written by J.S.Marsland as part of his research into the excess noise factor in avalanche photodiodes (APDs). The GUI will be produced using the GUIDE package supplied with the MATLAB software combined with the MATLAB programs. The GUI will then be used to compare this research work with the research work of others e.g. the Monte Carlo calculations made by the research group at the French Aerospace Laboratory (ONERA). Comparison with other research work will require the digitization of some graphs published in academic journals.