Temperature-controlled testing apparatuses

Various apparatuses are equipped with heating and cooling system, which are able to control soil temperature in a wide temperature range of -10 to 80C. Using these thermal apparatuses, the cyclic thermo-mechanical behaviour of saturated and unsaturated soils are systematically investigated, with application to energy pile, high-speed railway embankment, landfill cover and frozen ground. 

Advanced apparatuses enabling complex loading conditions

This laboratory possesses the hollow cylinder torsional shear device and true triaxial apparatus. Compared with the conventional triaxial apparatus, these apparatuses are much more versatile and powerful. They are used to simulate many complex loading conditions for constitutive model verifications as well as to test soil behaviour under various field loading conditions such as seismic loading, wave loading and traffic loads.

Mechanical and electromagnetic wave-based characterizations of soil properties

Mechanical and electromagnetic wave-based systems are developed to investigate the anisotropic soil stiffness, which is important for analysing ground response under dynamic loads and the serviceability of civil engineering structures. Some examples are given here: (a) Resonant column designed to determine shear moduli and damping ratios of soil specimens at small strains; (b) Unsaturated triaxial apparatus equipped with three pairs of bender elements for measuring anisotropic stiffness; (c) True triaxial apparatus with bender element system and I-scan system (tactile pressure sensors) for multi-purposes, e.g., measuring stiffness and associated anisotropy changes during soil aging, monitoring the evolution of contact forces during the aging process; (d) Multi-functional oedometer cell with mechanical and EM wave-based sensing system for characterizations of soil behaviour, e.g., monitoring the formation of clay fabric associations during the sedimentation process, and characterizing clay fabric associations using the spectral dielectric responses. 

Geotechnical testing based on 3D printing technique

The geotechnical group in HKUST benefits from the application of 3D printing techniques on innovation of geotechnical testing devices and sensing techniques. Examples include (a) A biaxial system with flexible boundaries is designed to characterize the features of particle motion and associated contact movement in response to shearing, using the particle image velocimetry (PIV) technique. The 3D printing technique is applied to ease manufacture of the testing device and testing sample with very high accuracy. (b) 3D printed portable oedometer and tailor-made oedometer ring with a needle probe to measure pore water pressure and film-like sensor to measure K0.

Geo-environmental room

The geo-environmental room (4 m  4.5 m  2.8 m) is designed to control various atmospheric parameters, including air temperature, relatively humidity, rainfall intensity and light intensity within a particular waveband favourable for plant photosynthesis and plant growth. This room is adopted to investigate the mechanisms of atmosphere-plant-soil interactions. The results provide a scientific basis for a wide range of applications, such as the stabilization of shallow slope, erosion control, design of earthen landfill cover, phytoremediation, and promoting the growth of Chinese medicinal plants. 

Apparatuses for studying internal erosion and surface erosion

The stress-controlled internal erosion testing apparatus control hydraulic gradient and stress state independently. It allows a systematic investigation of the initiation and development of internal erosion subjected to complex stress states. In addition, a great benefit of this apparatus is its capability to investigate the stress-strain behaviour of the soil immediately after the internal erosion test. The Jet index erodibility test apparatus was modified from the ASTM standard D5852-00 apparatus, to allow testing the erodibility of relatively coarse soils and to eliminate turbulent effects of water inflow. The apparatus provides an important means for investigating the initiation of debris flows, soil and water conservation, and sediment transport.

Physical models with innovative instrumentations

Various physical models with innovative instrumentations are built. The first example is a water flume with innovative instrumentation. In particular, low-cost and small-size MEMS (Micro-Electro-Mechanical-Systems) accelerometers and a MEMS sensing package, termed the Smart Soil Particle (SSP, first generation), is used to monitor movements of the slope body. Another example is a new pressure chamber with advanced sensing devices for model pile test. It allows for characterizing stress evolution in the soil surrounding the model pile during pile installation and setup, using the tactile pressure sensors and mechanical wave-based tomography imaging.

Data-enabled Scalable Research Laboratory

The Data-enabled Scalable Research Laboratory (DESR Lab) is the Makerspace specialized in the applications of Geotechnical Internet of Things (Geo-IoT), Deep Learning, and Big Data Analytics on the sustainable city development, e.g., critical infrastructure monitoring and slope health monitoring, and an open platform for geotechnical industries to collaborate and share resources.

References

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