Experimental Study on Deformation Mechanism of a Utility Tunnel in a Ground Fissure Area

This paper discusses the deformation mechanism of a utility tunnel crossing active ground fissures in Xi’an as observed in a physical model test. The purpose of this work is to confirm the precise effects of ground fissures on utility tunnels. The physical simulation experiment is carried out to measure the earth pressure and the strain relationship of the structure and the structural displacement. The structure appears to have been destroyed by torsion. The structural deformation located in the tunnel’s footwall was more serious than that in the hanging wall. However, at the top of the utility tunnel structure, the earth pressure in the footwall was less than that in the hanging wall. The increased range of the hanging wall at 0.3–1.5 m (the prototype within the range of 22.5 m) and decreased range of the footwall at 0.3–0.8 m (the prototype within the range of 12 m) were basically consistent with changes in the contact pressure at the structure’s bottom. This was roughly consistent with the main deformation zone of ground fissures mentioned in the specification, with the hanging wall at 0–20 m and footwall at 0–12 mm. Displacement meter data shows that the structure tends to deform to the lower right as the utility tunnel is “twisted” clockwise. These observations mark a notable departure from the previously published failure mode of metro tunnels under active ground fissures.

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Correction of Earth Pressure and Analysis of Deformation for Double-Row Piles in Foundation Excavation in Changchun of China

Advances in Materials Science and Engineering ◽

10.1155/2016/9818160 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Yijun Zhou ◽

Aijun Yao ◽

Haobo Li ◽

Xuan Zheng

Keyword(s):

Physical Model ◽

Model Test ◽

Large Scale ◽

Similarity Theory ◽

Earth Pressure ◽

Physical Model Test ◽

Deep Foundation ◽

Foundation Pit ◽

Double Row ◽

The Earth

In order to study the earth pressure and the deformation behavior of the double-row piles in foundation excavation, a large-scale physical model test was introduced to simulate deformation of double-row piles in foundation excavation based on the principle of similarity theory in this paper. Represented by the deep foundation pit engineering of Changchun, the strain and the displacement of the double-row piles and the earth pressure are calculated by the above-mentioned physical model test. Then a numerical simulation has been carried out to validate practicability of the physical model test. The results show that the strain and the displacement of the front-row piles are larger than the back-row piles. The earth pressure of the front-row piles appears to be “right convex,” correcting the specification of the earth pressure and putting forward the coefficient of β. The results in this paper may provide constructive reference for practical engineering.

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Effect of support characteristics on the earth pressure in a jointed rock mass

Canadian Geotechnical Journal ◽

10.1139/cgj-2014-0437 ◽

2015 ◽

Vol 52 (12) ◽

pp. 1956-1967 ◽

Cited By ~ 5

Author(s):

Moorak Son ◽

Solomon Adedokun

Keyword(s):

Rock Mass ◽

Earth Pressure ◽

Numerical Approach ◽

Jointed Rock ◽

Jointed Rock Mass ◽

Physical Model Test ◽

Joint Shear Strength ◽

Rock Stratum ◽

Rock Types ◽

The Earth

This study examines the magnitude and distribution of earth pressures against a support system in a jointed rock mass according to the support characteristics (strut stiffness and spacing), different rock types, and joint conditions (joint shear strength and joint inclination angle). A series of numerical parametric analyses were performed after verifying the numerical approach through a physical model test. These analyses were based on the discrete element method, which can take into account the joint characteristics of the rock strata and the interactions between the ground and the retaining structure. The results were compared with Peck’s earth pressure for soil ground, which showed that the magnitude and distribution of earth pressure are strongly affected by the support characteristics, rock types, and joint conditions, and that the earth pressure in the rock stratum can be significantly different from that in the soil ground. The results suggest that the support characteristics, including the rock types and joint conditions, are important factors affecting the earth pressure, and should be considered for the safe and economic design and construction of retaining structures in a jointed rock mass.

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FEM Simulation of Earth Pressure on Geosynthetic-Reinforced Soil Retaining Wall under Variable Rate Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.266 ◽

2012 ◽

Vol 594-597 ◽

pp. 266-269

Author(s):

Fu Lin Li ◽

Fang Le Peng

Keyword(s):

Finite Element ◽

Retaining Wall ◽

Earth Pressure ◽

Reinforced Soil ◽

Physical Model Test ◽

Variable Rate ◽

Geosynthetic Reinforced Soil ◽

Rate Dependent ◽

The Earth ◽

Dependent Behavior

On the basis of the Dynamic Relaxation method, a nonlinear finite element method (FEM) analysis procedure was developed for the geosynthetic-reinforced soil retaining wall. The FEM procedure technique incorporated the unified three-component elasto-viscoplastic constitutive model which can consider the rate-dependent behavior of both the backfill soil and the geosynthitic reinforcement. A simulation was performed on a physical model test on geosynthetic-reinforced soil retaining wall to validate the presented FEM. Extensive finite-element analyses were carried out to investigate the earth pressure distributions from the back of retaining wall under variable rate loading. It is shown that this FEM can well simulate the rate-dependent behavior and the earth pressure of geosynthetic-reinforced soil retaining wall.

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Physical Model Test for the Interaction on Circular Cross-Section Tunnel Crossing Ground Fissure with 60°

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.933 ◽

2011 ◽

Vol 261-263 ◽

pp. 933-937

Author(s):

Kai Ling Li ◽

Yang Liu ◽

Yu Ming Men ◽

Jing Ping Yan ◽

Hong Jia Liu

Keyword(s):

Physical Model ◽

Cross Section ◽

Model Test ◽

Hanging Wall ◽

Circular Cross Section ◽

Structural Deformation ◽

Physical Model Test ◽

Tunnel Structure ◽

Ground Fissure ◽

Longitudinal Strains

Physical model test about the interaction between tunnel structure and soil under circler tunnel crossing the ground fissure belt with 60° was carried out, measuring the longitudinal strains of structure, the relative displacement at the bottom of the tunnel and the surrounding rock pressure. The test results show the deformation on the tunnel structure with circular cross-section is a composition of bending, shearing and twisting. The main deformation in first stage of settlement is bending, but the twisting deformation is more outstanding after the void appears at the bottom of the tunnel. Structural deformation in hanging wall is larger than that of the footwall, whereas structural stress in footwall is larger than that of the hanging wall. The segmentation of lining tunnel structure should be utilized to fit the distortion, bending and shearing in the metro tunnel aslant crossing the ground fissure belt. Twisting action should be considered in the structural design, and the tunnel structure in footwall should be strengthened by using high-performance concrete.

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Calculation of the Vertical Strata Load of Utility Tunnel Crossing Ground Fissure Zone

Shock and Vibration ◽

10.1155/2020/8877016 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Dan Zhang ◽

Zhiping Hu ◽

Ganggang Lu ◽

Rui Wang ◽

Xiang Ren

Keyword(s):

Soil Layer ◽

Earth Pressure ◽

Reference Value ◽

Additional Stress ◽

Fissure Zone ◽

Engineering Structures ◽

Ground Fissure ◽

Ground Fissures ◽

Utility Tunnel ◽

Surrounding Soil

A ground fissure is a geological disaster in which the vertical dislocation of strata causes surface rupture. Ground fissures can cause extreme harm to the surface and underground buildings. Ground fissure activity can result in different settlement on the two sides of the strata, which will generate additional stress (pressure) that differs from the stress of the general stratum on underground structures across the ground fissure zone. It is essential to assess the effective stress of strata in the design of underground engineering structures across a ground fissure zone. The Xi’an ground fissure through a utility tunnel was focus of the research, and a physical model and data for oblique crossing of the 45° ground fissure were analyzed. A model of the utility tunnel structure was established, including the surrounding soil load as an active ground fissure environment. This model was used to calculate the vertical formation pressure of the overlying soil on the utility tunnel. A method to calculate the overlying load on the utility tunnel caused by ground fissure activity was proposed and compared with the calculation based on the A. Marston principle. The results showed that the ground fissure load calculation method based on the strata-holding effect can effectively calculate the earth pressure of the surrounding soil layer of the utility tunnel in the cross-ground fissure section. The results of this work provide guidance and reference value for the design of a utility tunnel in an area with the potential for a ground fissure.

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Extensive study on the impact of joint inclinations on the earth pressure in rock ground

10.21203/rs.3.rs-190601/v1 ◽

2021 ◽

Author(s):

Solomon Adedokun ◽

M. Son

Keyword(s):

Distinct Element ◽

Earth Pressure ◽

Extensive Study ◽

Physical Model Test ◽

Rock Types ◽

The Earth ◽

Universal Distinct Element Code ◽

Distinct Element Code ◽

Level Of Significance ◽

The Impact

Abstract The impact of different joint inclinations on the earth pressure was extensively carried out in this study, using Universal Distinct Element Code (UDEC) which is based on discrete element method. Numerical parametric investigations, which considered varying joint inclinations and rock types, were conducted after the numerical method had been verified through a physical model test. The joint angles considered ranged from 0º to 90º in the interval of 5º and the rock types are hard, slightly and moderately weathered rocks. The results of the analyses were subjected to statistical analysis using analysis of variance (ANOVA) at 5% level of significance, and compared with empirical earth pressure envelope for sand ground. The comparisons showed that earth pressures in rock ground are substantially varied from those in sand ground. The result of ANOVA revealed that joint inclinations have statistically significant effect on magnitude of the earth pressure, and practitioners should consider this factor while designing retaining structure in rock masses.

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Research on Calculation Theory of Double-Row Piles Retaining Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.671-674.251 ◽

2013 ◽

Vol 671-674 ◽

pp. 251-256

Author(s):

Jing Cao ◽

Kai Yu Jiang ◽

Yue Gui ◽

Hai Ming Liu

Keyword(s):

Surface Morphology ◽

Deformation Mechanism ◽

Slip Surface ◽

Earth Pressure ◽

Calculation Model ◽

Distribution Characteristics ◽

Double Row ◽

Retaining Structure ◽

The Earth ◽

Engineering Practices

The double-row piles retaining structure (DRPRS) is widely applied in the excavation engineering, but its calculation theory is immature and in appropriate. Based on the theory of earth pressure distribution, the distribution characteristics of earth pressure is analyzed to different layout form, and the general formula of earth pressure is derived. From the perspectives of the morphology of slip surface, linear slip surface morphology and broken-line slip surface morphology are proposed based on the feature of the DRPRS. A new calculation model is proposed combining the earth pressure and slip surface morphology. On this basis, one example is used to analyze the force and deformation mechanism of the DRPRS in detail. The research results can guide the engineering practices and promote the development of calculation theory for the DRPRS.

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Coordinated optimization control of shield machine based on dynamic fuzzy neural network direct inverse control

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331220980274 ◽

2020 ◽

pp. 014233122098027

Author(s):

Xuanyu Liu ◽

Wentao Wang ◽

Yudong Wang ◽

Cheng Shao ◽

Qiumei Cong

Keyword(s):

Fuzzy Neural Network ◽

Control Method ◽

Earth Pressure ◽

Screw Conveyor ◽

Inverse Control ◽

The Earth ◽

Coordinated Optimization ◽

Optimization Control ◽

Fuzzy Neural ◽

Shield Machine

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.

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