The Downhole Installation Technology of Herrick Shield Machine is Discussed

2021 ◽  
Author(s):  
Zhu Wen ◽  
Xuening Rong ◽  
Zhen Wang ◽  
Songtong Han ◽  
Ziming Xiong ◽  
...  

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Tim Jurisch ◽  
Stefan Cantré ◽  
Fokke Saathoff

A variety of studies recently proved the applicability of different dried, fine-grained dredged materials as replacement material for erosion-resistant sea dike covers. In Rostock, Germany, a large-scale field experiment was conducted, in which different dredged materials were tested with regard to installation technology, stability, turf development, infiltration, and erosion resistance. The infiltration experiments to study the development of a seepage line in the dike body showed unexpected measurement results. Due to the high complexity of the problem, standard geo-hydraulic models proved to be unable to analyze these results. Therefore, different methods of inverse infiltration modeling were applied, such as the parameter estimation tool (PEST) and the AMALGAM algorithm. In the paper, the two approaches are compared and discussed. A sensitivity analysis proved the presumption of a non-linear model behavior for the infiltration problem and the Eigenvalue ratio indicates that the dike infiltration is an ill-posed problem. Although this complicates the inverse modeling (e.g., termination in local minima), parameter sets close to an optimum were found with both the PEST and the AMALGAM algorithms. Together with the field measurement data, this information supports the rating of the effective material properties of the applied dredged materials used as dike cover material.


Author(s):  
Xuanyu Liu ◽  
Wentao Wang ◽  
Yudong Wang ◽  
Cheng Shao ◽  
Qiumei Cong

During shield machine tunneling, the earth pressure in the sealed cabin must be kept balanced to ensure construction safety. As there is a strong nonlinear coupling relationship among the tunneling parameters, it is difficult to control the balance between the amount of soil entered and the amount discharged in the sealed cabin. So, the control effect of excavation face stability is poor. For this purpose, a coordinated optimization control method of shield machine based on dynamic fuzzy neural network (D-FNN) direct inverse control is proposed. The cutter head torque, advance speed, thrust, screw conveyor speed and earth pressure difference in the sealed cabin are selected as inputs, and the D-FNN control model of the control parameters is established, whose output are screw conveyor speed and advance speed at the next moment. The error reduction rate method is introduced to trim and identify the network structure to optimize the control model. On this basis, an optimal control system for earth pressure balance (EPB) of shield machine is established based on the direct inverse control method. The simulation results show that the method can optimize the control parameters coordinately according to the changes of the construction environment, effectively reduce the earth pressure fluctuations during shield tunneling, and can better control the stability of the excavation surface.


2011 ◽  
Vol 71-78 ◽  
pp. 32-36 ◽  
Author(s):  
Xin Jiang Wei ◽  
Jie Hong ◽  
Gang Wei

Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by Double-O-Tube (DOT) shield tunnel was simulated by 3D MIDAS/ GTS software, and the impact of construction on the building was analyzed. The results show that: the ground settlement trough caused by DOT shield tunnel can be fitted by peck formula; during the passage of the shield tunneling through the building, the settlement of the building increased and settlement trough was wilder; the settlement was stable and had a little rebound when shield machine already passed the building; with the increase of driving distance, the first principal stress P1 increased and then was stable; with the increase of L, the shape of foundation settlement curve changed, and the maximum differential settlement between columns increased but was small.


2012 ◽  
Vol 170-173 ◽  
pp. 322-326
Author(s):  
Kui Chen ◽  
Ren Hua Yang ◽  
Tao Xu ◽  
Ya Jing Qi

In order to study the relationship between the design parameters of the shield machine and the strength of rock, the behaviours of rocks under the conventional triaxial compression, the complete stress-strain curves under different confining pressures of three typical rocks, i.e. granite, limestone and red sandstone, were taken out for analysis. From the curves, the values of elastic modulus E and Poisson's ratio μ were gained and the relationships between the following parameters were figured out, which are peak strength versus confining pressure, residual strength versus confining pressure, strain at peak strength versus confining pressure, and strain at residual strength versus confining pressure. According to the values and relationships, the complete stress-strain curves were divided into three parts. For each part, a constitutive equation was established by using the strain softening trilinear elastic-brittle-plastic constitutive model, and all the related parameters in the constitutive equations were also presented, which provide a theoretical foundation for the digital design of the cutter head and cutters of Shield machine.


2015 ◽  
Vol 817 ◽  
pp. 115-120 ◽  
Author(s):  
Dan Zhang ◽  
Le Yu Zhou ◽  
Chao Lei Zhang ◽  
Chao Huang ◽  
Min Zhao ◽  
...  

Network carbide inheritance during heat treatment process of large shield machine bearing steel GCr15SiMn was investigated by heat treatment experiments and quantitative metallographic. Samples with the proeutectoid cementite network thickness in the range of 0.19~0.54 μm were obtained by changing austenitizing temperature and soaking time of pearlite transformation. The results show that the network in hot rolled bar can be improved when the pre-heat treatment temperature is 950 °C. When the network thickness is above 0.40 μm, the undissolved cementite networks present in microstructures after quenching and tempering. In a Chinese standard, the network grades are 1.5 and 3.0 degree when the networks thickness are 0.40 μm and 0.54 μm, respectively. The critical network thickness that can be eliminated by heat treatment is 0.29 μm.


2016 ◽  
Vol 693 ◽  
pp. 1479-1485 ◽  
Author(s):  
Jian Zhao ◽  
Xue Wu Hong ◽  
Ming Yu ◽  
Zhi Peng Gao ◽  
Wen Jin Wang

Shield machine plays an indispensable role in the mining, transportation, underground engineering, hydraulic engineering and municipal construction. Shield cutters of shield construction process often appears serious deformation, damage that leads to engineering accident, or even a threat to human life and safety. In order to provide high precise data for shield machine cutter tool dynamic modification and to diagnose the shield machine cutter tool fault, the dynamic characteristic of the shield machine cutter tool system, which is the main component of a shield machine cutter tool, has to be obtained precisely. The compute modal parameters identification method base on the finite element method is proposed to identify the modal parameters of the shield machine cutter tool. By means of Solidwords software, the knife ring structure of the shield machine tool and the tool is designed; then build the tool the finite element model, modal analysis, obtained the dynamic characteristics, and find out the weak link, put forward the improvement measures and prolong its life. Therefore, the study on dynamic characteristics of shield machine cutter, for the optimization design of domestic tool, has an important significance improve tool life.


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