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Protection of cement-soil reinforced regions for adjacent running tunnels during pit excavation

岩石力学与工程学报 2018年第A01期37卷 3674-3685页

作者： WANG Li ZHENG Gang school of civil engineering Tianjin University school of civil and Safety engineering Dalian Jiaotong University

In pit excavation,cement is introduced into ground by deep mixing method to form an improved soil raft below final formation level to diminish deflection of retaining wall and effect on surrounding structure.Owning to complicated site conditions and improper workmanship,there are always some regions left untreated in the embedded improved soil raft.In this work,Several schemes of cement-soil mixed piles arrangement are modeled in order to discuss the effect of different cement-soil reinforced regions on protection for adjacent running tunnels.Finite element results show that:when lateral regions above tunnels are not enhanced by cement-soil mixed piles,effect of enlarging vertical enhanced regions around tunnels on diminishing lateral displacement of tunnel is really small;enhancing the lateral regions next to retaining wall is more effective in reducing the deflection of tunnel and retaining wall;uplifting of tunnel under the middle pit mainly depends on lateral reinforced regions and lateral displacements of retaining wall;as cement-soil mixed piles near retaining wall in east pit are removed during east pit excavation,effect of cement-soil mixed piles in east pit on reducing the final wall deflection can be neglected;upward shaft resistances are exerted along left side of diaphragm wall during excavation,which helps to reduce the wall deflection;positive effect of single-head cement-soil mixed piles in east pit is to decreasing the uplifting of soil inside east pit.Double-head cement-soil mixed piles arranged in"T"shape decrease the effect of east pit excavation on tunnels under middle pit apparently.

关键词： mining engineering deep mixing method cement-soil mixed piles pit excavation deflection uplifting

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Simulation Platform of Underwater Quadruped Walking Robot Based on MotionGenesis Kane 5.3 and Central Pattern Generator

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Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 24-29页

作者： Ke Yang Xu-Yang Wang Tong Ge Chao Wu school of Naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

It will still in lack of a simulation platform used to learn the walking of underwater quadruped walking robot. In order to alleviate this shortage,a simulation platform for the underwater quadruped walking robot based on Kane dynamic model and CPG-based controller is constructed. The Kane dynamic model of the underwater quadruped walking robot is processed with a commercial package MotionGenesis Kane 5. 3. The forces between the feet and ground are represented as a spring and damper. The relation between coefficients of spring and damper and stability of underwater quadruped walking robot in the stationary state is studied. The CPG-based controller consisted of Central Pattern Generator( CPG) and PD controller is presented,which can be used to control walking of the underwater quadruped walking robot. The relation between CPG parameters and walking speed of underwater quadruped walking robot is investigated. The relation between coefficients of spring and damper and walking speed of underwater quadruped walking robot is studied. The results show that the simulation platform can imitate the stable walking of the underwater quadruped walking robot.

关键词： underwater quadruped walking robot MotionGenesis Kane 5.3 CPG

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On the Survivability of Self-repairing Control System for a Hybrid Underwater Vehicle

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Journal of Harbin Institute of Technology(New Series) 2014年第1期21卷 32-42页

作者： Biao Wang Chao Wu Tong Ge school of Naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

A hybrid remotely operated underwater vehicle( HROV) capable of working to the full ocean depth has been developed. In order for the vehicle to achieve a certain survivability level,a self-repairing control system( SRCS) has been designed. It consists of two basic technologies,fault diagnosis and isolation( FDI) and reconfigurable control. For FDI,a model-based hierarchical fault diagnosis system is designed for the HROV. Then,control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies,it can obtain the fundamental frame of SRCS for the HROV. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes,an assessment of the HROV's survivability is vitally needed before it enters operational service. This paper presents a new definition of survivability for underwater vehicles and develops a simple survivability model for the SRCS. As a result of survivability assessment for the SRCS,we are able to figure out the survivability of SRCS and make further optimization about it. The methodology developed herein is also applicable to other types of underwater vehicles.

关键词： survivability self-repairing HROV full ocean depth control system

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Modeling and Control of Head of the Underwater Snake-like Robot Swimming

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Journal of Harbin Institute of Technology(New Series) 2014年第1期21卷 77-83页

作者： Ke Yang Xu-Yang Wang Tong Ge Chao Wu school of Naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

In order to solve oscillation of head of the underwater snake-like robot,the Central Pattern Generator( CPG)-based control scheme with head-controller was presented. The Kane dynamic model was constructed to be processed with a commercial package MotionGenesis Kane 5. 3,to which the proposed control scheme was applied. The relation between CPG parameters and orientation offset of head was investigated. The target orientation of head-controller was calculated through a convenient method. The advantage of this control scheme is that the head of the underwater snake-like robot remains in the forward direction during swimming. To prove the feasibility of the proposed methodology,two basic motion patterns,swimming along the straight line and swimming along the curved path,had been implemented in our simulation platform. The results showed that the simulation platform can imitate the swimming of the underwater snake-like robot and the head of the underwater snake-like robot remains in a fixed orientation directed towards the target. The oscillation of head's orientation is inhibited effectively.

关键词： underwater snake-like robot CPG-based control scheme head-controller MotionGenesis Kane 5.3

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A simplified method for the determination of vertically loaded pile-soil interface parameters in layered soil based on FLAC3D

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Frontiers of Structural and civil engineering 2016年第1期10卷 103-111页

作者： Jiu-jiang WU Yan LI Qian-gong CHENG Hua WEN Xin LIAN school of civil engineering and architecture Southwest University of Science and Technology Mianyang 621010 China Department of Geological engineering Southwest Jiaotong University Chengdu 610031 China Faculty of civil engineering Guangxi University of Science and Technology Liuzhou 545006 China

堆积土壤相互作用的数字分析通常要求很多试用工作决定接口参数和精确性不能通常被保证。就这而言，这份报纸首先进行敏感分析在沙在单个堆积的适用的行为上弄明白接口参数的影响。然后，为在分层的土壤的堆积土壤接口参数的决心的一个... 详细信息

堆积土壤相互作用的数字分析通常要求很多试用工作决定接口参数和精确性不能通常被保证。就这而言，这份报纸首先进行敏感分析在沙在单个堆积的适用的行为上弄明白接口参数的影响。然后，为在分层的土壤的堆积土壤接口参数的决心的一个简化方法基于参数研究被建议。最后，提起的装载测试被用于简化方法，和计算结果的确认与监视数据同意很好。一般来说，简化方法在这建议纸与更高的精确性工作并且与传统的试用工作相比消费更少的时间，特别在界面的连贯、界面的磨擦角度的决心上。

关键词：界面参数层状地基 FLAC3D 竖向荷载桩土桩-土相互作用敏感性分析试验工作

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Contact-impact formulation for multi-body systems using component mode synthesis

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Acta Mechanica Sinica 2013年第3期29卷 437-442页

作者： Peng Chen Jin-Yang Liu Jia-Zhen Hong Department of engineering Mechanics School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University

The efficiency and accuracy are two most concerned issues in the modeling and simulation of multi-body systems involving contact and impact. This paper proposed a formulation based on the component mode synthesis method for planar contact problems of flexible multi-body systems. A flexible body is divided into two parts： a contact zone and an un-contact zone. For the un-contact zone, by using the fixed-interface substructure method as reference, a few low-order modal coordinates are used to replace the nodal coordinates of the nodes, and meanwhile, the nodal coordinates of the local impact region are kept unchanged, therefore the total degrees of freedom （DOFs） are greatly cut down and the computational cost of the simulation is significantly reduced. By using additional constraint method, the impact constraint equations and kinematic constraint equations are derived, and the Lagrange equations of the first kind of flexible multi-body system are obtained. The impact of an elastic beam with a fixed half disk is simulated to verify the efficiency and accuracy of this method.

关键词： Contact-impact analysis · Flexible multi-body system · Component mode synthesis

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General forms of elastic-plastic matching equations for mode-Ⅲ cracks near crack line

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Applied Mathematics and Mechanics(English Edition) 2009年第5期30卷 549-559页

作者：易志坚赵朝华杨庆国彭凯黄宗明 school of civil engineering and architecture Chongqing Jiaotong University school of civil engineering Chongqing University

Crack line analysis is an effective way to solve elastic-plastic crack problems. Application of the method does not need the traditional small-scale yielding conditions and can obtain sufficiently accurate solutions near the crack line. To address mode- Ⅲ crack problems under the perfect elastic-plastic condition, matching procedures of the crack line analysis method axe summarized and refined to give general forms and formulation steps of plastic field, elastic-plastic boundary, and elastic-plastic matching equations near the crack line. The research unifies mode-III crack problems under different conditions into a problem of determining four integral constants with four matching equations. An example is given to verify correctness, conciseness, and generality of the procedure.

关键词： mode-Ⅲ crack elastic-perfectly plastic material crack line analysis crack line plastic zone

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Surface Modification of Fire-retardant Asphalt with Silane Coupling Agent

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Journal of Wuhan university of Technology(Materials Science) 2012年第2期27卷 310-315页

作者：陈辉强 school of civil engineering & architecture Chongqing Jiaotong Univeisity

The theory and approach of the surface modified of asphalt fire-retardant with silane coupling agent were introduced. The optimum silane dosage was determined, and the structure and properties of the asphalt fire-retardant before and after the surface modification were characterized by infrared spectrum and thermo gravimetric analysis. The dispersion effect of asphalt flre-retardant was studied. The influence of the surface modification on the hydrophilicity and lipophilicity of the asphalt fire-retardant was analyzed. The experimental results showed that there were physical and chemical interactions between the silane coupling agent and the asphalt fire-retardant, which reduced the surface polarity of the asphalt fire retardant. The optimum silane coupling agent dosage was 0.95% of the asphalt fire retardant. The surface modification improved the thermal stability, dispersibility and lipophilicity of the asphalt fire retardant, which enhanced the compatibility between asphalt fire retardant and asphalt.

关键词： silane asphalt fire-retardant coupling agent surface modification

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Spectral-Energy Efficiency Tradeoff in Mixed-ADC Massive MIMO Uplink with Imperfect CSI

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Chinese Journal of Electronics 2019年第3期28卷 618-624页

作者： DING Qingfeng JING Yindi school of Electrical and Automation engineering East China Jiaotong University Department of Electrical and Computer engineering University of Alberta

An uplink multi-user massive Multiinput multi-output(MIMO) system is considered with a mixed Analog-to-digital converter(ADC) architecture under imperfect Channel state information(CSI). A closed-form approximation for the Spectral efficiency(SE)is derived for a general mixed ADC structure with any resolution profile. To achieve a balance between the SE and receive Energy efficiency(EE) of the system, the ADC resolution profile optimization problem that maximizes a linear combination of the SE and the Base station(BS)receive power consumption is formulated. An algorithm based on gradient search is proposed whose complexity is linear in the number of BS antennas. Numerical results verify that the proposed ADC resolution design largely outperforms the two-level structure especially in the lower SE region and provides more choices than the uniformADC architecture for resolving the SE-EE tradeoff.

关键词： Massive MIMO Mixed-ADC receiver Spectral-energy efficiency tradeoff Gradient search Imperfect channel state information

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A buoyancy vertical transport system of deep-sea mining

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Journal of Ocean engineering and Science 2020年第3期5卷 294-295页

作者： Shijun Liao State Key Laboratory of Ocean engineering Shanghai 200240China school of Naval architecture Ocean and Civil EngineeringShanghai Jiaotong UniversityShanghai 200240China

Generally speaking,the systems of deep-sea mining consist of a mining support vessel at surface,a seafloor collector on seabed,and a vertical transport system connecting them.The traditional vertical transport systems of deep-sea mining,which are either hydraulic or airlift,have low efficiency and high cost.In this paper,a kind of buoyancy vertical transport system of deep-sea mining is briefly described.Unlike the traditional ones,this new transport system is based on buoyancy and gravity,which could work in arbitrary depth of water but cheaper.

关键词： Deep-sea mining Vertical transport system Buoyancy South china sea

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