A new mini-grating absolute displacement measuring system for static and dynamic geomechanical model tests

Measurement ◽  
2017 ◽  
Vol 105 ◽  
pp. 25-33 ◽  
Author(s):  
Shucai Li ◽  
Hanpeng Wang ◽  
Yong Li ◽  
Qingchuan Li ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Model Tests ◽  
Measuring System ◽  
Geomechanical Model ◽  
Absolute Displacement

scholarly journals Geomechanical Model Tests and Infrared Detection of Rock Responses for Tunnels Excavated in Sedimentary Rocks

2017 ◽  
Vol 191 ◽  
pp. 20-30 ◽  
Author(s):  
Weili Gong ◽  
Manchao He ◽  
Hong Yan ◽  
Lifeng Li ◽  
Xiaodong Xu
Keyword(s):  
Sedimentary Rocks ◽  
Model Tests ◽  
Infrared Detection ◽  
Geomechanical Model

scholarly journals Application of Micro Earth Pressure Cells to Geomechanical Model Tests of Arch Dams

2020 ◽  
Vol 570 ◽  
pp. 062042
Author(s):  
WANG Senhao ◽  
CHEN Yuan ◽  
ZHANG Lin ◽  
YANG Baoquan ◽  
DONG Jianhua ◽  
...  
Keyword(s):  
Earth Pressure ◽  
Model Tests ◽  
Geomechanical Model ◽  
Arch Dams

Large-scale geomechanical model testing of an underground cavern group in a true three-dimensional (3-D) stress state

2010 ◽  
Vol 47 (9) ◽  
pp. 935-946 ◽  
Author(s):  
W. S. Zhu ◽  
Q. B. Zhang ◽  
H. H. Zhu ◽  
Y. Li ◽  
J.-H. Yin ◽  
...  
Keyword(s):  
Stress State ◽  
Large Scale ◽  
Three Dimensional ◽  
Great Depth ◽  
Model Tests ◽  
Geomechanical Model ◽  
Testing Procedures ◽  
Test Initiation ◽  
The Stability ◽  
Made In

The stability of a large cavern group at great depth is discussed on the basis of large-scale three-dimensional (3-D) geomechanical model tests and numerical simulations. The model tests are described in detail. Improvements in the tests were made in terms of experimental techniques and advanced measurement methods. The model tests utilized active loading on six sides of a rock mass in a true 3-D stress state. During the model construction, precast blocks were fabricated and monitoring holes were defined prior to test initiation. Newly developed combination ball-sliding walls were installed on each of the major loading surfaces to reduce the friction induced by model deformation. A unique grouting and installation technique employing prestressed cables was adopted in the tests. A digital photogrammetric technique, displacement sensing bars using fiber Bragg grating (FBG) technology, and mini multipoint extensometers were developed for measuring deformation. Overloading tests were then conducted for different overburden depths, and 3-D numerical analyses were performed to simulate the testing procedures. Conclusions regarding the stability of the cavern group were developed based on a comparison between the experimental and numerical results.

Comparative Study of Motions and Drift Forces in Waves and Current

2017 ◽  
Author(s):  
Florian Sprenger ◽  
Elin Marita Hermundstad ◽  
Jan Roger Hoff ◽  
Dariusz Fathi ◽  
Ørjan Selvik
Keyword(s):  
Degrees Of Freedom ◽  
Ocean Basin ◽  
Model Tests ◽  
Measuring System ◽  
Diffraction Radiation ◽  
Station Keeping ◽  
Wave Drift ◽  
Wave Drift Forces ◽  
General Cargo ◽  
Drift Forces

Station keeping analysis is an important activity in the early stages of any vessel/DP project that eventually determines the machinery and thruster configuration and thruster size selection. In order to obtain reliable results, it is crucial to apply engineering tools that realistically represent the flow physics and resulting hydrodynamic forces. Present computer tools are based on the assumption that wave drift- and current forces can be superimposed. However, there are also mutual interaction effects between waves, current and hulls that should be accounted for in the evaluation of the wave drift forces. In MULDIF, a 3D diffraction/radiation panel code developed by SINTEF Ocean within the framework of a JIP, this wave-current-body interaction is taken into consideration by a new potential flow numerical model. A case study with offshore vessels and general cargo ships of different main dimensions has been performed to assess the capabilities of MULDIF for station keeping purposes in wave and current environments. The first-order vessel motions as well as mean second-order drift forces for 0 kn forward speed without current have been calculated. Through an interface to SINTEF Ocean’s vessel response code VERES, MULDIF offers the possibility to include viscous roll damping due to hull friction, flow separation at bilge keels, lift effects as well as normal forces acting on bilge keels and hull pressure created by the presence of bilge keels. This reduces roll motions to a realistic extent as shown by the comparison of RAOs from MULDIF calculations and model tests. Roll reduction tank effects can currently only be considered through the external damping matrix. Model tests for the selected vessels have been performed in SINTEF’s Ocean Basin in a soft-mooring arrangement in different irregular sea states and headings in deep water. The models were equipped with two two-component force transducers, measuring the x- and y- components of the forces. The yaw moments have been calculated from the y-force measurements. In order to measure the vessel motions in six degrees of freedom, an optoelectronic position measuring system has been used. Selected cases illustrate the significant influence of wave-current interaction on motions and drift forces.

Sign in / Sign up

Export Citation Format

Share Document