Field test and deformation controlling for single tunneling lining stability

The construction process of anchor,fiber concrete and its mechanical principle of interaction with surrounding rocks is studied by field tests from the view of researching stability of single layer tunneling lining. The mechanical properties of single layer lining in the practical application of tunnel engineering are measured. On the basis of this study,the mechanism of single layer tunnel lining is discussed,which is finally applied to the engineering practice,formatting a set of theoretical support for the design method of single layer lining. Studies found that close effect between fiber reinforced concrete and rock is well,which shows that the single layer lining design method to ensure quality and safety proposed in this paper is feasible,and construction characteristic of retaining structure is reliable. The method can be widely applied in engineering practice,and has remarkable economic benefit and social benefit.     

Load Calculation Method of Shallow Tunnel under Unsymmetrical Loadings in Broken Surrounding Rock

Tunnel portal section mostly faces unfavorable geologic and topographical conditions, such as broken surrounding rock, shallow and unsymmetrical loadings. The current Chinese code for design of road tunnel provides the load calculation method of tunnel under unsymmetrical. However, according to the mechanic and deformation characteristics of the tunnel lining on site, the assumption is not suitable for the shallow tunnel under unsymmetrical loadings in broken surrounding rock. Therefore, through engineering case analysis and results of three-dimensional numerical analysis, the failure mechanism of shallow tunnel under unsymmetrical loadings in broken surrounding rock is presented firstly, that is, deep buried side broken surrounding rocks slump down after excavation and squeeze the lining, which makes the lining deform outward and bear passive earth pressure. Through the failure mechanism, the surrounding rock mainly includes slumping area and passive area. Then the corresponding formulas are deduced based on limit equilibrium theory. Finally, a case study is adopted to verify the feasibility of the new method. It is show that the new method is more reasonable than the method of current code.     

Theoretical calculation and monitoring on rock pressure of shallow-buried bilateral bias neighborhood tunnel

In order to research the tunnel rock pressure and its distribution, the mechanical model of tunnel rock pressure of shallow-buried bilateral bias neighborhood tunnel is set up based on series assumptions. The calculation theory of tunnel rock pressure is deduced, in which the construction processes of twin tunnels can be considered. Furthermore, the contact pressure between tunnel lining and surrounding rock is monitored on site at Zuan Qianmen Tunnel of Xinbao expressway, and the change law of contact pressure corresponding with time and construction processes is obtained. Meanwhile, the comparison analysis has been made between field monitoring value and theoretical value, and the result shows that the tunnel rock pressure’s mechanical model and calculation theory of shallow-buried bilateral bias neighborhood tunnel is rational, which will provides the theory foundation to tunnel design and tunnel rock pressure calculation of shallow-buried bilateral bias neighborhood tunnel.     

Average Temperature Distribution of the Ceiling Jet in Train Fires in Tunnels

The flame ceiling jet is easily formed while the on fire train stops in the tunnel. The iterative formula is derived to calculate the average temperature of the flame ceiling jet when the fire source is set on the center of the train by establishing a one dimensional model of the unit control volume, and the heat exchange is considered among the flame smoke and the wall of the tunnel and the train. Undetermined coefficients in the iterative formula are determined by small scale model experiments with the scale factor of 1:8 and numerical simulation. The calculated values of temperature by the iterative formula are consistent well with the measured values, and the maximum error of calculation is no more than 7%, which indicates that the iterative formula is reliable. The results show that the distributions of the average temperature of flame ceiling jet are in the exponential form, but there are some differences between that above the train and that in the tunnel. Two prediction formulas for the flame ceiling jet average temperature changing along the longitudinal tunnel are obtained by the sub fitting method. The results can provide reference for the alarm parameter selection, device settings in tunnel, safety evacuation of the passenger, as well as the analysis of the destructive effects on the tunnel lining structure caused by tunnel fire.     

Calculation of Crack Space and Crack Width of Tunnel Lining Based on Elastic Foundation Curved Beam Model

Based on the elastic foundation beam,the control differential equation of tunnel lining is worked out,according to the theory of Saint-Venant,the predominance equation about the center angle to the crack space is established, then the crack space of tunnel lining under the loads can be worked out and according to the crack space,the crack width can be calculated.     

Analysis on Interaction of Transversely Isotropic Soil and Lining with a Partially Sealed Tunnel

The soils have anisotropic properties in the deposition process, so regarding the soil as anisotropy medium is more reasonable. Considering the interaction of the soil and lining, and based on the theory of saturated porous medium and elastic, the harmonic coupled vibrations of the transversely isotropic soil and lining with a partially sealed circular tunnel are investigated subjected to the harmonic load in the frequency domain. The analytical expressions of the displacement, stress and pore water pressure of the transversely isotropic soil and lining are obtained by the stress continuous in the inner boundary of the lining and stress and displacement coordination at the interface of the soil and lining. The boundary conditions for partial permeable of the tunnel are established by the fluid velocity equality at the lining and soil. Then, the specific expressions of undetermined coefficient are given. The influence of material and geometric parameter of the soil and lining are studied by the numerical example, it is shown that the elastic modulus in the transversely isotropic plane has a great influence on the system dynamic responses, while the influence of elastic modulus vertical the transversely isotropic is smaller. In addition, the relative permeable coefficient and the lining thickness have big impacts on the responses amplitude, while the influence of poisson’s ratio of lining is smaller.     

System Platform of Auto Industry Based ASP and SRM

In view of the situation of auto industry, a system platform is given based on ASP and SRM. For the Co-management and information exchange of SRM, dynamic co-mode and estimated principium are designed. Based on four influence factors of auto industry, focuses on the process of supply not the result. Based on problem definition, formulation of criteria, qualification and choice, the process of estimate is improved. Implementation result shows that this kind of system platform can improve the efficiency of information exchange and achieve the goal of Co-management.     

A new type of prestressed concrete hollow girder design for overcoming the typical diseases

This paper proposes a new type of prestressed concrete hollow girder based on the summaries of the current studies on longitudinal cracks and hinge cracks. The match prefabricated method is used with shear key at interface to solve the problem of hingle cracks, and the two-way prestressing strand techniques are used to assure the longitudinal load-bearing capacity and to prevent the emergence of longitudinal cracks because of pressure existing at the match interface. In order to reduce the temperature difference between the internal and external of the prestressed concrete hollow girder, drilling holes are carried out at the bottom slab of girder every distance. To ensure the adhesive effect between the girder and deck pavement, we designed grooves at the top slab of girders. The finite element analysis results of a design example show that the pressure stress of bottom slab of girder is about 2.58 MPa and 0.16 MPa, which are effective to avoid the appearance of longitudinal cracks and hinge cracks.     

Interval local orthogonal element-free Galerkin method for the plane with cracks

In order to solve the problem that some structural parameters have errors or uncertainties which are caused by manufacture, installation, measurement or computation in structural analysis and design, an interval local orthogonal element-free Galerkin method(ILOEFGM）is proposed. Based on the interval mathematics, inner product space, perturbation theory, element-free Galerkin method(EFGM）are employed to deduce ILOEFGM equilibrium equations, and the parameter perturbation of interval number is used to solve the ILOEFGM equilibrium equations. As an application of the method, a numerical example based on the problem for plane with cracks is given. The calculated results show that the method is effective.     

Small scale wind tunnel for high pressure and high energy discharge

A kind of small scale wind tunnel with low velocity is proposed according to the characteristics of strong ionization discharge chamber and the demands of discharge for flux, velocity and flow fields. On the precondition that the airflow field and velocity is satisfied, aerodynamic design and structural design are carried out. Key techniques are studied including overall structure, aerodynamic and structural design of airflow vent and collection vent, aerodynamic and structural design of power section, flow rate adjustment and control, and cooling system of motor. Based on the design scheme, a small scale wind tunnel with strong ionization discharge for an enterprise is developed. Application indicates that the small scale wind tunnel is a practical and effective airflow loop device for high pressure and strong ionization discharge with the features of stability and reliability.     

Combination Forecasting Models Using Regression Analysis Method

Using regression analysis method,the methods for solving the weights of combination forecasting model(CFM) are proposed. At first, the linear regress CFM are presented based on the least absolute criteria and least square criteria. Then the weights can be evaluated using the least square princinple. Because the objective function of CFM based on least absolute criteria is non differential, the traditional programming methods can not solve it. So the least square method with the modified weights is proposed to solve this problem. At the same time, methods for solving CFM is given with the aim of minimizing sum of percentage error absolutes. From many cases, the results show that the forecasting precision of CFM is very high and the effect of regression is remarkable.     

Analysis on the influence from rectangle cavity behind the lining to the primary support of tunnel

In process of the tunnel construction throw New Austrian Tunnelling Method, the result of smoothwall blasting to rock tunnel is not good, there are more and more cavities produced behind the lining. On the basis of engineering project, this paper makes the three-dimensional elastic-plastic analysis throw numerical simulation, discusses the stress-strain behavior of primary support when there is a different size of rectangle cavity behind the lining. In addition the safety factor of tunnel is calculated with cavity based on the strength reduction finit element method. This factor is compared with the factor of health tunnel. The stability of tunnel structure system is estimated through the linear regression analysis between stress of lining and safety factor.     

Elastic-Perfectly Plastic Solution of Tunnel Surrounding Rocks Using Mogi-Coulomb Strength Criterion

Reasonable choice of rock strength criteria is crucial for stress and displacement prediction and support design in tunnel engineering. Based on Mogi-Coulomb strength criterion and elastic-perfectly plastic model, analytical solutions of stress and displacement for surrounding rocks around a circular tunnel were derived The intermediate principal stress coefficient was used to present the intermediate principal stress effect. The results in this study were compared with the current solutions in the literatures and the influence of intermediate principal stress and shear strength parameters of surrounding rocks was discussed. The results showed extensive applicability and the Mohr-Coulomb strength criterion and Matsuoka-Nakai criterion are two special cases; when the intermediate principal stress coefficient b was equals to 0.5, the results indicated that the intermediate principal stress effect and its range for rock strength; the influence of cohesion and internal friction angle on the plastic radius and tunnel wall displacement was significant; Care should be taken to the effects of intermediate principal stress and shear strength parameter variations of surrounding rocks on tunnel design and construction.     

Deformation Monitoring and Its Control in a Shallow buried Large span Tunnel Constructed Using the Pile Beam Arch Method

Deformation monitoring and control measures of a shallow buried large span tunnel constructed using the pile beam arch (PBA) method are described, taking the North Gongti Road Station of Beijing Metro line 10 as an example. Based on the monitoring datum, the crown settlement, convergence, ground settlement of the tunnel and the bridge foundation settlement are analyzed. The results show that (1) the PBA tunneling method can restrain the ground settlement and deformation of a shallow buried large span tunnel; (2) the depth, tunnel span and pilot tunnel construction may influence the deformation of a shallow buried large section tunnel significantly; and, (3) advanced conduit grouting, timely preliminary support and permanent lining construction can reduce the deformation effectively.     

Reasons of Tunnel Disease and Disease Management on Highway

Based According to the on the careful investigation in site of highway tunnel, the classification of tunnel disease is obtained. , design and construction of tunnel, in relation to the distribution of stress and loading of tunnel by numerical analysis and back analysis, the existing condition and reasons of tunnel diseases are carefully analyzed. At the same time, the disease management methods are provided, which are important to guide similar tur/nel to search diseases reasons and manage diseases.     

Wind Tunnel Tests of Long Span Half - through Arch Bridge Section Model

Wind induced vibration is one of the main control factors in the Long span bridge structure design. The wind tunnel tests for measuring the static wind forces on the bridge girder and the section model wind tunnel dynamic testing for Caiyuanba Yangtze River Bridge in Chongqing are introduced in this paper. The wind tunnel testing for measuring static wind forces and vortex- induced vibration test on the arch are introduced taking account of the influence between two arches. The main contents and outcomes of testing are presented. It is indicated that the bridge girder has excellent wind stability and the arch mechanical characters are rather complicated. The drag force on the hind arch varied a lot because of the font arch interference on the wind flow. The drag force on the hind arch will be negative when two arches are close to each other. It increases with the space of two arches. The results of testing will give the data of buffeting and vortex - induced vibration and flutter analysis of the bridge.     

One Auto-optimized Fuzzy Control of Car-engines Based on GA

One new auto-optimized fuzzy control model of car-engines based on genetic arithmetic was introduced aiming at the problem that the parameters of car-engine are of the discreteness, the nonlinear and the uncertain characteristics, with which it is difficult to control accurately the excess air coefficient and the spark advance angle in dynamic procedure when using a conventional control model. The rule of the design scheme of the controller achieving the model based on embedded operating system is discussed. Further more, it is probed that the fuzzy control parameters are optimized automatically using GA based on on-line real-time simulation. The results of experiments show that the dynamic indexes and the fuel economy indexes are all improved greatly and the advantage of the model on reducing fuel consumption is obvious.     

Mechanical and Deformation Characteristicson Shield Tunnel Segment with Cracks

The 3D Goodman element is used to simulate segments' cracks in one section of shield tunnel in Guangzhou. Mechanical and deformation characteristics of segment structure responded to varied depth of cracks is analyzed in this paper. Meanwhile, research on coefficient of lateral earth pressure, soil coefficient and ground water level on mechanical and deformation characteristics is carried out. The research result shows that along with the increase of cracks' depth, the tensile stress, pressure stress reach the maximum value while the increment is not too much. However, when the depth equals to the thickness of segment, the reinforcements' tensile stress has increase sharply, even exceeded the allowable value. Moreover, the maximum number of tensile stress, horizontal and vertical convergent value of shield tunnel segment with cracks increase with the reduction of the coefficient of lateral earth pressure and soil coefficient, and increase with the increase of ground water level as well. Specific repair measure has been taken to segments' cracks in this section of shield tunnel based on the conclusions. In general, this section of shield tunnel is stable and safe now, and there is no longer new cracks appeared.     

Communication method for electromechanical equipment on fully mechanized face with wirelessmesh network

Aiming at the problem that the pre-existing communication condition can’t satisfy the dynamic movement of the electric & mechanical equipment on fully mechanized face, a wireless communication method based on mesh network is proposed. The design of the dual antenna and the dynamic distribution method of channels based on the interference perception which make the limited bandwidth sources can be rationally used. A high throughput routing protocol and a multipath routing control are used for the efficient management of the wireless mesh network. The factors which affect the signal strength are analyzed to research the deployment method of the wireless network adapt to the fully mechanized face. Experiments are carried out and the result shows that the signal strength of the wireless mesh network is -41~-68 dBm and the data transfer rate is above or equal 12 Mbps. Thus, the mesh network can satisfy the requirement of the electric & mechanical equipment and the method is a new way to solve the communication problem on fully mechanized face.     

Efficiency of product collaborative innovation design based on the attribute and matching task

The degrees that the design agent capacity matches the design task are an important factor affecting the efficiency of collaborative product innovation design. The classification and quantitative calculation of different types of design agent capacity combination is carried out after the characteristic of design agent is analyzed. An efficiency model whose goal is the shortest entire time is constructed based on the definition of task attribute,and then the solving method of efficiency model are designed based on particle swarm optimization algorithm. The collaborative product innovation design of cabin is taken as an example to prove that considering the matching agent attribute with task can shorten the design cycle and improve design efficiency.