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Chamber earth pressure is one of the significant parameters during the Earth Pressure Balance (EPB) shield construction processing. The soil arching effect is existence when the tunnel depth is enough. It is significant to consider the influence of arching effect to analyze the pressure in soil chamber in shield tunneling. In this paper, the influence of arching effect is considered to calculate the chamber earth pressure. Firstly, the soil is supposed as loose media, and the necessary buried depth of producing arching affects is deduced according to the loose media theory. Then, based on the characteristic of proper arching axis, the equation and the height of proper arch are obtained. At last, the calculation formula of minimum chamber earth pressure of EPB shield tunnel is deduced which can consider the effect of arching effect.

For the complex earth conditions and uncertain factors, the earth pressure balance (EPB) shield tunneling is a complicated and high-risk process. There would cause some faults, such as earth caking, soil occluding in the capsule, water spewing, surface settlement. To avoid them, this paper applies artificial neural network (ANN) to predict the common shielding faults. The neural network is trained by several samples about the tunnel boring machine’s (TBM) parameters, and then it will have self-learning to identify the fault. With the parallel computing ability, the network could detect and predict abnormal behaviors online. This paper includes three parts, firstly, the introduction of EPB, and four usual blockings; and then the principle of BP neural network is present, for the defect of BP algorithm, two kinds of improved BP algorithms are applied in the network; finally, an simulation is given to illustrate the prediction.

The tunnel construction often encounters the problem of adaptability of sand-gravel formation and earth pressure balance shield (EPBS) construction, which has brought new technical problems and challenges to those who are participating in the construction project. In order to ensure the normal operation of shield construction, the soil must have ideal plasticity and liquidity, and low permeability to intercept groundwater. Therefore, we must adopt the soil improvement techniques ,namely, to inject the modified materials (mud, foam, polymer, etc.) into excavation face and earth pressure tank(if necessary, to the screw conveyor) to ensure the stability of excavation face, achieve EPBS driving, and help to reduce mechanical load, reduce land subsidence, and increase driving speed at the same time. The ground improvement technique is an important part of the EPBS method. The quality of the application of soil improvement technology is very important to maintain the stability of excavation face and the screw dump device’s dumping smoothly. It also has a significant impact on the shield machine’s functioning safely,economically and efficiently.

A three-dimensional (3D) failure mechanism, based on the framework of the kinematical approach of limit analysis theory, is applied to calculate the face supporting pressure of a circular tunnel driven by the Earth Pressure Balance Shield (EPBS). The geometry of the mechanisms considered is composed of a sequence of truncated rigid cones. The numerical results obtained are presented.

Aiming at medium distance transportation of excavated spoil and constructional components in the tunnelling process, this paper combines with a water-conveyance tunnel engineering and analyzes the influence factors that affect the construction efficiency of earth pressure balance shield(EPB shield), and then works out an available scheme based on that the transport link should well match with shield tunnelling. The field condition indicates that the equipment lectotype, marshaling and transport organization in this scheme guarantee the transport capacity and continuity for tunnelling, which ensures construction progress. The idea in this design can provide similar engineering with reference.

Referring to the Earth Pressure Balance (EPB) shield with the diameter of 6.25m, a new experiment station of EPB shield is proposed, which is loaded with mechanical structure instead of traditional soil box. The structure of the experiment model is designed for the performance analysis of the EPB shield. The mechanical loading device, which is called the soil simulator, can simulate different geological environments. The soil simulator is capable of realizing three work states, such as earth balance pressure, earth under pressure, and earth over pressure. By adopting virtual prototype technology, parametric model of the shield station is established and the co-simulation scheme is determined. Besides, the kinematic analysis as well as variation principles between the displacement and driving forces of the propulsion system are obtained, which build the foundation for optimization design and control of the shield prototype.

In this paper, the technology based on site investigation adequately, through reading, analysis and comprehensive vast literature of shield lining segments, installed spelling were analyzed, and the conclusion that some valuable conclusions. Summarizes the construction process of shield technology, and introduces the earth pressure balance type shield construction machine structure and working principle. Shield technology is with modern transportation, underground engineering, mining, water conservancy projects and municipal construction needs and developed advanced tunnel construction technology. With China's urban underground transportation facilities, the quickening of the process of shield technology has become the hotspot of domestic engineering.

The type and properties of the grouting materials contribute great impact on the grouting effect. The new grout with hydrated lime, fly ash, bentonite, sand, water and water reducer as materials was developed, and the raw material requirements and performance requirements of the new grout were ascertained. Some experimental results were illustrated on the fineness modulus of sand and water reducer dosage impact on the properties of the new grout. The preliminary application results in Shanghai and Soochow metro showed that the new grout played a very good role on the surface subsidence control both in fine clay soil and sand strata.

The type and performance indicators of the grout contribute great impact on the grouting effect. Uniform test method was adopted on the mix design optimization of the new grout, and the raw material requirements and performance requirements of the new grout were developed. Test results of the new grout, inert grout, and cement grout performances were compared and conclusions were drawn that the overall performances of the new grout were better than the other two type grouts. The modification of injection pump and pipe for the new grout injection were introduced, the preliminary application results of Shanghai and Suzhou metro showed that the new grout played a very good role on the surface subsidence control.

Soil improvement by foam is a key technique to control formation damage in shield construction. The half-life of three kinds foam was obtained by test self-developed foam and other two types. Meanwhile, their characteristics of stability and dissipation were analyzed. The physical-mechanical characteristic of red clay which was improved by foam was tested. Test result show that as the foam concentration increasing, the cohesion and plastic fluidity of soil increases firstly and then decreases, but the internal fiction angle decrease always. The permeability of red clay was measured by penetration test. The impregnation depth of foam in red clay was analyzed. The results provide key parameters for shield construction to prevent engineering accidents, such as, flowing, sand gushing, mud boiling, collapse and so on.

The method to analysis the strength of planetary trains’ carriers of EPB(earth pressure balance) shield machine is presented in this paper. The structure of the shield machine trains is analyzed and the 3-D solid model of the carrier is built with Pro/E. After the load on the carrier has been dealt with, the strength of carrier is calculated by means of finite element method. The results via ANSYS show that the max stress and strain on the carriers are increasing as the increasing load on it. The max stress is lying on the joint point of the carrier and planetary gear shaft because of the bending deformation of the shaft.

Analysis and design cannot be solved until a proper model of hydraulic control system of earth pressure balance shield machine is built. There are two kinds of modeling methods in common use. (1) Dynamic mathematical modeling. Two models, transfer function and state space, are mainly included. For linear system, the two methods can be provided with a fairly complete theoretical framework. However, if the system is in the complicated working environment or it is non-linear, the modeling process needs a mass of mathematical verification. This has become a limitation for application of these methods; (2) Graphical Modeling. It is more direct for the complex hydraulic control system of earth pressure balance shield machine. First, the main components are separately modeled. Then connect them according to the flow direction of signal. Some special software, such as AMESim, can be used to simplify the simulation process.

The method to analysis the strength of planetary trains’ carriers of EPB(earth pressure balance) shield machine is presented in this paper. The structure of the shield machine trains is analyzed and the 3-D solid model of the carrier is built with Pro/E. After the load on the carrier has been dealt with, the strength of carrier is calculated by means of finite element method. The results via ANSYS show that the max stress and strain on the carriers are increasing as the increasing load on it. The max stress is lying on the joint point of the carrier and planetary gear shaft because of the bending deformation of the shaft.