Developments of Geotechnical Monitoring Techniques and Warning System
DPWE develops geotechnical monitoring techniques and warning system using transmission line based monitoring techniques, such as optical and electromagnetic wave methods. Engineering or environmental parameters can be provided by analyzing the reflections of waves. Furthermore, the transmission line based monitoring techniques are parts of automatic monitoring system incorporating with data acquisition (DAQ) and related self-developed software. These techniques have advantages of durability, maintenance, multiplex, and multifunction. The research topics are listed as following:
Fiber optic monitoring technique
- Fiber optic ground displacement measurement
- Fiber optic ground water level measurement
- Full fiber optic based tri-axial testing device
Single mode uniform period FGB pressure transducer
Full fiber optic based tri-axial testing device
Time domain reflectometry monitoring technique
- Soil dielectric and electrical conductivity measurement
- Soil water content and density measurement
- Suspended sediment concentration (SSC) measurement in rivers and reservoirs
- Ground and structure deformation measurement
- Liquids level, sediement level, scouring, settlement, and displacement measurement
TDR SSC monitoring - Floating system in Shihmen reservoir
TDR slop sliding monitoring system
Engineering Geophysical Survey
Geophysical survey methods, similar with the MRI (Magnetic resonance imaging) techniques in medical science and engineering, promptly provide the engineering properties (e.g., elastic modulus and electrical properties) of mass target area. Thus, these methods are broadly used for applications, such as investigations of engineering geology, environmental pollution, geological hazard, and soil improvement. Some geophysical survey methods and apparatus used in DWPE are shown as following:
- Refraction seismic method
- Surface wave seismic method
- Electrical resistivity tomography (ERT)
- Ground penetration radar (GPR)
- Borehole geophysical investigation (PS-Logging, borehole diameter, borehole inclination, electrical resistivity, and televiewer.)
Surface wave seismic method—shear velocity tomography
ERT applied for tunnel collapse investigation
Soft-rock tri-axial testing device
Physical Properties Investigations and Developments of Related Test Methods for Soft Rock
Due to young geological conditions in Taiwan, the strength of soft rocks locates between those of rocks and soils. Therefore, the DPWE promotes research topics involving investigations and verifications for engineering mechanism of soft rock. Some related works:
- Erosion mechanism and erodibility evaluation of soft rock riverbed
- The ultimate bearing capacity of shallow foundation on poorly cemented sandstone
- Development of soft-rock tri-axial testing devices
- Borehole multifunction apparatus for soft rock
Mass scouring in DaAn river
Fundamental Research
DPWE also focuses on the fundamental research in geotechnical engineering. Some topics are listed as follows:
- Investigation method for gravel-bed river material
- Cyclic behavior analysis of a silty sand in central western Taiwan
- Origin of colluvial deposit & mechanical behavior
- Land subsidence induced by groundwater withdraw in complex strata
- Application of geology survey using borehole acoustic and optical televiewers
- Numerical simulations of seepage related anomaly in embankment dam
- Study on the disaster mitigation strategies for landslide dams
Relationships between effective stress and shear stain, initial shear modulus and shear stain of silty sand
Measured borehole image from acoustic televiewer