An Approach to Determine the Stiffness Reduction Factor of Tunnel Lining

2011 ◽  
Vol 243-249 ◽  
pp. 3659-3662
Author(s):  
Hai Ying Zhou ◽  
Li Xin Li ◽  
Ting Guo Chen
Keyword(s):  
Numerical Analysis ◽  
Flexural Rigidity ◽  
Resistance Coefficient ◽  
Reduction Factor ◽  
Tunnel Lining ◽  
Soil Resistance ◽  
Stiffness Reduction ◽  
Simplified Method

Based on the segmental joint tests, it was found that the practical range of joint flexural rigidity was in range of 8500-29000kN•m/rad. A simplified method for determining the stiffness reduction factor of tunnel lining() was proposed using results from the segmental joint tests in which some parameters were obtained by calibration against a 3D Numerical analysis. The influence of joint flexural rigidity, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius on the stiffness reduction factor of tunnel lining was examined. The stiffness reduction factor can be simply expressed as a function of joint flexural rigidity ratio, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius for the typical tunnel lining.

scholarly journals Analysis of Laterally Loaded Piles in Undrained Clay Concave Slope

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chong Jiang ◽  
Xintai Li ◽  
Pan Liu ◽  
Li Pang
Keyword(s):  
Interaction Model ◽  
Reduction Factor ◽  
Soil Resistance ◽  
Initial Stiffness ◽  
Laterally Loaded Piles ◽  
Simplified Method ◽  
Curve Model ◽  
Calculation Results ◽  
Laterally Loaded ◽  
Theoretical Results

A concave slope is a common type of slope. This paper proposes a simplified method to study the effect of a clay concave slope on laterally loaded piles. The hyperbolic p - y curve model is selected as the lateral pile-soil interaction model of the concave slope. Considering the two angles of the concave slope, the variation of the ultimate soil resistance with depth is divided into two parts, and the ultimate soil resistance varies nonlinearly with depth. The reduction factor method and normalization method are used to obtain the initial stiffness. The theoretical results will be compared with the calculation results of the 3D FE analysis to prove the rationality of this method. Finally, the simplified method is used to analyze the response of laterally loaded piles under different parameters.

scholarly journals Numerical Analysis of the Contact Behavior of a Polymer-Based Waterproof Membrane for Tunnel Lining

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2704
Author(s):  
Kicheol Lee ◽  
Dongwook Kim ◽  
Soon-Wook Choi ◽  
Soo-Ho Chang ◽  
Tae-Ho Kang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Numerical Analysis ◽  
Material Properties ◽  
Interfacial Adhesion ◽  
Laboratory Experiments ◽  
Tunnel Lining ◽  
Contact Conditions ◽  
Contact Behavior ◽  
Initial Strength ◽  
Interface Parameters

Waterproof membranes have higher initial strength, faster construction, and better waterproofing than conventional sheet membranes. In addition, their polymer constituents have much higher interfacial adhesion and tensile strength than those of conventional materials. However, despite their advantages, waterproof membranes are not widely used in civil construction. This study evaluates the material properties and interface parameters of a waterproof membrane by considering the results of laboratory experiments and numerical analysis. Since the contact behavior of a membrane at its interface with shotcrete is important for understanding the mechanism of the support it offers known as a shotcrete tunnel lining, modeling should adopt appropriate contact conditions. The numerical analysis identifies the suitability and contact conditions of the waterproof membrane in various conditions.

Stiffness Reduction Factor for Flat Slab Structures under Lateral Loads

2009 ◽  
Vol 135 (6) ◽  
pp. 743-750 ◽  
Author(s):  
Sang-Whan Han ◽  
Young-Mi Park ◽  
Seong-Hoon Kee
Keyword(s):  
Reduction Factor ◽  
Lateral Loads ◽  
Flat Slab ◽  
Stiffness Reduction

Design and Analysis of Buried Liquid Petroleum Gas Storage Bullets Supported on Multiple Saddles (PVP2010-25052)

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Radoslav Stefanovic ◽  
Yaser Noman
Keyword(s):  
High Pressure ◽  
Petrochemical Industry ◽  
Gas Storage ◽  
Differential Settlement ◽  
Soil Resistance ◽  
Bending Moments ◽  
Ambient Temperatures ◽  
Liquid Petroleum Gas ◽  
Simplified Method ◽  
Design Construction

The use of large, high pressure liquid petroleum gas (LPG) storage bullets has become a common, and often assumed safe, practice in the petrochemical industry. The Engineering Equipment and Materials Users Association (EEMUA) is an organization that has attempted to address design aspects related to mounded or buried bullets; Publication No. 190 published by the EEMUA (2000, Guide for the Design, Construction and Use of Mounded Horizontal Cylindrical Vessels for Pressurized Storage of LPG at Ambient Temperatures, EEMUA, London, England.) became a standard practice in the industry. However, the design recommended, and therefore addressed, by Publication 190 is for bullets directly supported by soil (i.e., without saddle supports). However, it has been noticed by the authors that many users are requesting these storage bullets be supported by saddles resting on foundations in order to minimize the chance of unexpected settling and any motion of the bullets underground. The large span of these bullets requires more than two saddles adding to the complexity of the design due to statically indeterminate construction, differential settlement, and uneven supports. This paper focuses on major issues related to the design of such bullets. First, the loads induced by mound weight, pressure due to mound, and the loads due to longitudinal thermal expansion and soil resistance to this expansion is analyzed. Next, a method for calculating the multiple saddle reactions and bending moments at spans and supports is provided. A simplified method for assessing the effect of differential settlement between saddles is proposed.

Batter Pile Static Load Test and Analysis

2012 ◽  
Vol 256-259 ◽  
pp. 1139-1143
Author(s):  
Li Lan Zhang ◽  
Yao Dong Wu
Keyword(s):  
Stress State ◽  
Static Load ◽  
Resistance Coefficient ◽  
Load Test ◽  
Soil Resistance ◽  
Test Results ◽  
Static Load Test ◽  
Foundation Soil ◽  
Load Analysis ◽  
Actual Stress

This paper through the test results and theoretical calculation of the batter pile static load, analysis of the actual stress state of cables, and according to the test results to determine the level of the foundation soil resistance coefficient ratio and allow level a transplant.

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