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Intelligent direct analysis of physical and mechanical parameters of tunnel surrounding rock based on adaptive immunity algorithm and BP neural network

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Journal of Pharmaceutical Analysis 2009年第1期21卷 22-30页

作者： Xiao-rui Wang1,2. Yuan-han Wang1, Xiao-feng Jia3..School of civil engineering and Mechanics,Huazhong University of Science and {2., Wuhan 43.074,china 2.Department of civil engineering,nanyang institute of technology,nanyang 473.04,china 3.Department of Chemistry and Bioengineering,nanyang institute of technology,nanyang 473.04,china. School of civil engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China Department of civil engineering Nanyang Institute of Technology Nanyang 473004 China Department of Chemistry and Bioengineering Nanyang Institute of Technology Nanyang 473004 China

Because of complexity and non-predictability of the tunnel surrounding rock, the problem with the determination of the physical and mechanical parameters of the surrounding rock has become a main obstacle to theoretical research and numerical analysis in tunnel engineering. During design, it is a frequent practice, therefore, to give recommended values by analog based on experience. It is a key point in current research to make use of the displacement back analytic method to comparatively accurately determine the parameters of the surrounding rock whereas artificial intelligence possesses an exceptionally strong capability of identifying, expressing and coping with such complex non-linear relationships. The parameters can be verified by searching the optimal network structure, using back analysis on measured data to search optimal parameters and performing direct computation of the obtained results. In the current paper, the direct analysis is performed with the biological emulation system and the software of Fast Lagrangian Analysis of Continua (FLAC3.. The high non-linearity, network reasoning and coupling ability of the neural network are employed. The output vector required of the training of the neural network is obtained with the numerical analysis software. And the overall space search is conducted by employing the Adaptive Immunity Algorithm. As a result, we are able to avoid the shortcoming that multiple parameters and optimized parameters are easy to fall into a local extremum. At the same time, the computing speed and efficiency are increased as well. Further, in the paper satisfactory conclusions are arrived at through the intelligent direct-back analysis on the monitored and measured data at the Erdaoya tunneling project. The results show that the physical and mechanical parameters obtained by the intelligent direct-back analysis proposed in the current paper have effectively improved the recommended values in the original prospecting data. This is of p

关键词： adaptive immunity algorithm BP neural network physical and mechanical parameters surrounding rock direct-back analysis

Assessing a soft twin tunneling numerical model using field data

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Journal of Pharmaceutical Analysis 2009年第1期21卷 36-41页

作者： Ke-shuan Ma1,2.Lie-yun Ding11. School of civil engineering and Mechanics,Hubei Key Laboratory of Control Structure, Huazhong University of Science & {2., Wuhan 43.074, china 2. Department of civil engineering, nanyang institute of technology, nanyang 473.04, china. School of civil engineering and Mechanics Hubei Key Laboratory of Control Structure Huazhong University of Science and Technology Wuhan 430074 China Department of civil engineering Nanyang Institute of Technology Nanyang 473004 China

Using a five-floor building affected by the Yangtze River highway tunnels in Wuhan as the engineering background, we have constructed a free-field model and a coupled model to study the soil, lining, foundations and upper structure, and analyze the rules of movements of building foundation and ground induced by single tunnel and twin tunnel excavation with the Finite Element Analysis method. It is shown that for the coupled model, the longitudinal displacement of each foundation increases slowly when the tunnel face gets close to the foundation section and then increases fast when the tunnel face moves away from the foundation during the single and twin tunneling. For a single tunnel, the surface settlements are overestimated by the free-field and coupled tunnel. This might be crucial in urban areas. Regarding the maximum settlements and the width of the settlement trough, the difference between the free-field model and the coupled model is quite obvious. This comparison with the field measurement value reveals that the coupled model seems to be superior to the free-field model. These results are of instructive significance for design and excavation.

关键词： finite element analysis three-dimensional slurry shield tunneling building settlement

The characteristics of arc beam shaping in hybrid plasma and laser deposition manufacturing

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Science china(Technological Sciences) 2006年第2期49卷 238-247页

作者： ZHANG Hai’ou1, QIAN Yingping1,3. WANG Guilan1 & ZHENG Qiguang2.1. School of Material Science and technology, Huazhong University of Science and technology, Wuhan 43.074, {2. 2. institute of Laser technology and engineering, Huazhong University of Science and technology, Wuhan 43.074, {2. 3. Mechanical engineering College, Hubei University of technology, Wuhan 43.068, {2. 1. School of Material Science and technology Huazhong University of Science and Technology Wuhan 430074 China 3. Mechanical engineering College Hubei University of Technology Wuhan 430068 China 2. institute of Laser technology and {2. Huazhong University of Science and Technology Wuhan 430074 China

As a new direct metal prototyping technology,the hybrid plasma and laser deposition manufacturing (PLDM) is proposed in this paper. In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc. Afterwards the sketch of picture is clearly obtained. And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally. The results show that the modality of plasma arc beam is markedly influenced by laser beam. And the improvements of shape precision and surface state of the layer deposited by PLDM are confirmed.

关键词： plasma hybrid laser, direct deposition, plasma arc beam, molding character, high-temperature alloy.

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3.1. Mechanics Department, Shandong University of technology, Zibo 2.5049, {3. 2. {2. engineering Department, Dalian University of technology, Dalian 11602., {3. 3. Mathematics Department, Ocean University of {3., Qingdao 2.6071, {3. Mechanics Department Shandong University of Technology Zibo 255049 China civil engineering Department Dalian University of Technology Dalian 116024 China Mathematics Department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

Theoretical analysis of natural frequency of externally prestressed concrete beam based on rigidity correction

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Journal of Pharmaceutical Analysis 2009年第1期21卷 31-35页

作者： Hui-xia Xiong1,2. Yao-ting Zhang11.School of civil engineering & Mechanics, Huazhong University of Science and {2., Wuhan 43.074, china 2.Department of civil engineering, nanyang institute of technology, nanyang 473.04, china. School of civil engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China Department of civil engineering Nanyang Institute of Technology Nanyang 473004 China

A dynamic test on externally prestressed simply supported concrete beams separately with three typical types of tendon distributions was conducted. The results show that the natural frequencies of the beams increase with the increase in the prestressing force at the tensioning stage, and the natural frequencies decrease after the cracks occur in the beams. Following the calculation formula of natural frequency of externally prestressed beam, which was reported in a literature, the natural frequencies of the experimental beams are calculated, and big errors are found between the test results and the calculated ones of natural frequency values. As a result, this paper has tried to adopt two methods to correct the rigidity parameter of the concrete beam in the formula for natural frequency calculation, and to use the corrected formula to calculate the frequencies of the experimental beams. The calculation results indicate a good consistency with the experimental ones, which verifies the feasibility of the corrected formula.

关键词： externally prestressed concrete beam natural frequency rigidity correction regression analysis

A land surface model incorporated with soil freeze/thaw and its application in GAME/Tibet

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Science china Earth Sciences 2006年第12期49卷 1311-1322页

作者： HU Heping1, YE Baisheng2. ZHOU Yuhua3.& TIAN Fuqiang1 1. Department of Hydraulic engineering, Tsinghua University, Beijing 100084, china 2. Cold and Arid Regions Environmental and engineering Research institute, Chinese Academy of Sciences, Lanzhou 73.000, china 3. Department of civil engineering, Massachusetts institute of technology, USA 1. Department of Hydraulic engineering Tsinghua University Beijing 100084 China 2. Cold and Arid Regions Environmental and engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China 3. Department of civil engineering Massachusetts Institute of Technology USA

Land surface process is of great importance in global climate change, moisture and heat exchange in the interface of the earth and atmosphere, human impacts on the environment and eco- system, etc. Soil freeze/thaw plays an important role in cold land surface processes. In this work the diurnal freeze/thaw effects on energy partition in the context of GAME/Tibet are studied. A sophisti- cated land surface model is developed, the particular aspect of which is its physical consideration of soil freeze/thaw and vapor flux. The simultaneous water and heat transfer soil sub-model not only reflects the water flow from unfrozen zone to frozen fringe in freezing/thawing soil, but also demon- strates the change of moisture and temperature field induced by vapor flux from high temperature zone to low temperature zone, which makes the model applicable for various circumstances. The modified Picard numerical method is employed to help with the water balance and convergence of the numerical scheme. Finally, the model is applied to analyze the diurnal energy and water cycle char- acteristics over the Tibetan Plateau using the Game/Tibet datasets observed in May and July of 1998. Heat and energy transfer simulation shows that: (i) There exists a negative feedback mechanism between soil freeze/thaw and soil temperature/ground heat flux; (ii) during freezing period all three heat fluxes do not vary apparently, in spite of the fact that the negative soil temperature is higher than that not considering soil freeze; (iii) during thawing period, ground heat flux increases, and sensible heat flux decreases, but latent heat flux does not change much; and (iv) during freezing period, soil temperature decreases, though ground heat flux increases.

关键词： land surface model,soil freeze/thaw,GAME/Tibet,simultaneous liquid,vapor and heat transfer.

New Solution to Surface Temperature of Casting Slab Measurement Based on Preceded Reflector and Multi-Wavelength

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Journal of Iron and Steel Research International 2012年第8期19卷 12-16页

作者： LIU Jun1, MA Jiao-cheng2. YANG Feng3. XIAO Hui1, RAO Li-min1 (1. School of Nuclear engineering and technology, East {2. institute of technology, Fuzhou 3.4000, Jiangxi, {2. 2. School of Mechanical engineering and Automation, Northeastern University, Shenyang 110004, Liaoning, {2. 3. School of civil and Environmental engineering, East {2. institute of technology, Fuzhou 3.4000, Jiangxi, {2.) [a] School of Nuclear engineering and technology East China Institute of Technology Fuzhou 344000 Jiangxi China [b] School of Mechanical engineering and Automation Northeastern University Shenyang 110004 Liaoning China [c] School of civil and Environmental engineering East China Institute of Technology Fuzhou 344000 Jiangxi China

The surface temperature of casting slab is an important parameter in the metallurgy field. Because the surface emissivity is uncertain and also unknown, it is difficult to measure the slab surface temperature accurately. A method based on preceded reflector and multi-wavelength was put forward to deal with the difficulty in surface temperature measurement of casting slab. On the premise of preceded reflector and non-preceded reflector, the method establishes the radiation energy equations and works out the emissivity and temperature in the equations. Also, the multilayer modeling of casting slab surface and multiple reflection-absorption process modeling were built by Monte Carlo method. The temperature measuring method had been applied in the continuous casting field. In order to verify the measured result, the thermal imaging method was adopted when the slab surface emissivity was set by repeated tests. Finally, the measured and verified temperature curves keep a same tendency and the error of the values is lower than 5℃. The comparison result shows that the method can measure temperature accurately.

关键词： casting slab emissivity surface temperature preceded reflector multi-wavelength

Early Hydration of Composite Cement with Thermal Activated Coal Gangue

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Journal of Wuhan University of technology(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 Department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2.content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2.and AFt. The cement with 3.% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

Performance-based methodology for assessing seismic vulnerability and capacity of buildings

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Earthquake engineering and engineering Vibration 2010年第2期9卷 157-165页

作者： Lin Shibin1, Xie Lili1, 2.Gong Maosheng1,2.and Li Ming1,3.1.institute of {3. Mechanics,{2. Earthquake Administration, Harbin 150080, {2. 2.School of civil {3.,Harbin institute of technology,Harbin 150090, {2. 3.School of civil {3.,Shenyang Jianzhu University,Shenyang 11016, {2. institute of engineering Mechanics China Earthquake Administration Harbin 150080 China

This paper presents a performance-based methodology for the assessment of seismic vulnerability and capacity of buildings. The vulnerability assessment methodology is based on the HAZUS methodology and the improved capacity- demand-diagram method. The spectral displacement (Sd) of performance points on a capacity curve is used to estimate the damage level of a building. The relationship between Sd and peak ground acceleration (PGA) is established, and then a new vulnerability function is expressed in terms of PGA. Furthermore, the expected value of the seismic capacity index (SCev) is provided to estimate the seismic capacity of buildings based on the probability distribution of damage levels and the corresponding seismic capacity index. The results indicate that the proposed vulnerability methodology is able to assess seismic damage of a large number of building stock directly and quickly following an earthquake. The SCev provides an effective index to measure the seismic capacity of buildings and illustrate the relationship between the seismic capacity of buildings and seismic action. The estimated result is compared with damage surveys of the cities of Dujiangyan and Jiangyou in the M8.0 Wenchuan earthquake, revealing that the methodology is acceptable for seismic risk assessment and decision making. The primary reasons for discrepancies between the estimated results and the damage surveys are discussed.

关键词： performance-based vulnerability building damage seismic capacity software HAZUS