Browsing by Author "Wang, Chien-Chih"

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Characterization of reservoir sediment under water with differential pressure-sensored flat dilatometer and piezo-penetrometer
(2013-08-01)
Lee, Jui-Ting
;
Wang, Chien-Chih
;
Ho, Yen-Te
;
Huang, An-Bin
;
土木工程學系
The unusually strong typhoons and heavy rainfalls occurred recently in Taiwan have caused major landslides in many reservoir catch basins. The debris from these landslides eventually settled in the reservoir and turned into mud. From soil mechanics point of view, the mud immediately in front of the dam where the reservoir is usually the deepest is a very young, normally consolidated or under-consolidated fine-grained soil. The engineering properties of the reservoir mud are important parameters in the planning and design of schemes to remove the mud. Yet, our knowledge in this regard is very limited. For some of the major reservoirs in Taiwan, the mud is often under more than 40 m of water. How to conduct effective geotechnical site characterization under these circumstances is a challenge. The authors developed techniques to incorporate differential pressure measurements in flat dilatometer (Delta DMT) and piezo-penetrometer (Delta Pu) tests to facilitate in situ measurements under water in a reservoir. A series of field Delta DMT and Delta Pu tests along with representative soil sampling were conducted at Tsengwen Reservoir in southern Taiwan. The paper describes the techniques of Delta DMT and Delta Pu tests, interpretation of available test data to obtain the engineering properties of the reservoir mud, and discusses implications in the future site characterization of reservoir mud.
Simplified monitoring and warning system against rainfall-induced shallow slope failures
(2018-10-01)
Wang, Chien-Chih
;
Chang, Wen-Jong
;
Huang, An-Bin
;
Chou, Shih-Hsun
;
Chien, Yu-Chun
A system that involves the use of a low-cost microelectromechanical system (MEMS)-based sensor stick and soil-water characteristic curve (SWCC) inferred from grain-size distribution was developed to assess the factor of safety against rainfall-induced shallow slope failure. The system allows water content at multiple depths to be monitored in the field. The corresponding suction and factor of safety against infinite slope failure are derived based on the estimated SWCC. The new system circumvents the use of tedious and often costly field as well as laboratory procedures while providing a quantitative slope stability assessment on a real-time basis. The paper introduces the background of the new development and describes the application of the sensor stick system in a field test.