The Triaxial Shear Test of Artificially Frozen Soils in Tunnel Construction of Hong Kong

2013 ◽  
Vol 353-356 ◽  
pp. 1653-1656
Author(s):  
Xiang Dong Hu ◽  
Jin Tai Wang
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Shear Test ◽  
Sewage Treatment ◽  
Tunnel Construction ◽  
Triaxial Shear Test ◽  
Frozen Soils ◽  
Ground Freezing ◽  
Artificial Ground Freezing ◽  
Design And Construction

Three kinds of frozen soils were tested for artificial ground freezing (AGF) project in the tunnel construction of Stonecutters Island Sewage Treatment Works, Hong Kong. Triaxial shear test was conducted to obtain shear strength of frozen soils. From the test, Mohr circles and their envelopes were obtained. According to Mohr circles, shear strength of the three soils was gained. Comparing the three soils, we found the potential weaken layer which might cause failure in the construction. All the parameters obtained can be used in design and construction of AGF practice.

Properties of Frozen Soils for Cross Passage Construction in Line 1 and 2 of Wuxi Metro

2013 ◽  
Vol 353-356 ◽  
pp. 1662-1665 ◽  
Author(s):  
Xiang Dong Hu ◽  
Yan Guang Han
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Freezing Point ◽  
Frozen Soil ◽  
Frost Heave ◽  
Soil Test ◽  
Frozen Soils ◽  
Freezing Method ◽  
Ground Freezing ◽  
Artificial Ground Freezing

Artificial ground freezing method (AGF) was applied in cross passage constructing of line 1 and 2 of Wuxi Metro. Mechanical properties of frozen soils such as uniaxial compressive strength, modulus of elasticity, Poissons Ratio, frost heave rate and freezing point are prerequisite for design and construction of AGF. In order to obtain the parameters mentioned, laboratory tests were conducted. One was the basic geotechnical test. Another was the frozen soil test.

Laboratory Test of Uniaxial Compressive Strength of Shanghai Frozen Soils under Freeze-Thaw Cycle

2013 ◽  
Vol 716 ◽  
pp. 688-692 ◽  
Author(s):  
Xiang Dong Hu ◽  
Jin Tai Wang ◽  
Xing Fu Yu
Keyword(s):  
Soft Soil ◽  
Underground Space ◽  
Freezing And Thawing ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Ground Freezing ◽  
Freeze Thaw Cycle ◽  
Artificial Ground Freezing ◽  
Mechanical Characters

The artificial ground freezing (AGF) is now widely employed in constructions with the expanding underground space exploitation in Shanghai. In order to avoid geological disasters which might appear in the AGF practice, it is urgently needed to do laboratory tests on the physical and mechanical characters of Shanghai soft soil under freezing and thawing action. This paper tests three kinds of soils from the location ofShanghai Metro line 4 constructions in different state, i.e. original state, freeze-thaw state and secondary freeze-thaw state, and obtains the changing rules of soil characters under secondary freeze-thaw action.

scholarly journals Artificial Ground Freezing Impact on Shear Strength and Microstructure of Granite Residual Soil Under an Extremely Low Temperature

2021 ◽  
Vol 9 ◽  
Author(s):  
Ran An ◽  
Xianwei Zhang ◽  
Lingwei Kong ◽  
Jianwu Gong ◽  
Xuewen Lei
Keyword(s):  
Shear Strength ◽  
Low Temperature ◽  
Magnetic Resonance Image ◽  
Large Scale ◽  
Friction Angle ◽  
Treatment Temperature ◽  
Residual Soil ◽  
Ground Freezing ◽  
Artificial Ground Freezing ◽  
Granite Residual Soil

The Artificial Ground Freezing (AGF) method, which is widely used in tunnel excavations, significantly affects the properties of geotechnical materials in frozen walls under extremely low temperatures. In order to simulate the AGF process, the freezing treatment with a temperature of −30°C and thawing treatment temperature of 25°C were performed on natural specimens of granite residual soil (GRS). Subsequently, triaxial (TRX) tests were conducted to evaluate mechanical properties and Nuclear Magnetic Resonance Image (NMRI) tests were applied to detect pore distributions of GRS. To clarify variations of microstructure after freezing-thawing, the relaxation time (T2) distribution curves and T2-weighted images from NMRI results were thoroughly analyzed from the perspective of quantization and visualization. Results show that the shear strength as well as the cohesion of GRS are reduced sharply by the AGF process, while the internal friction angle decreases gently. The pore size distribution (PSD) converted from the T2 curve is constituted of two different peaks, corresponding to micro-pores with diameters from 0.1 to 10 µm and macro-pores with diameters from 10 to 1,000 µm. Under the AGF impact, the expansion in macro-pores and shrinkage in micro-pores simultaneously exist in the specimen, which was verified from a visualized perspective by T2-weighted images. The frost heaving damage on shear strength is attributed to the microstructural disturbance caused by the presence of large-scale pores and uneven deformations in GRS, which is subjected to the AGF impact under an extremely low temperature.

Research on Shear Strength for Asphalt Mixture by the Uniaxle Penetration Test Method

2011 ◽  
Vol 97-98 ◽  
pp. 220-225 ◽  
Author(s):  
Yang Cai
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Linear Correlation ◽  
Shear Test ◽  
Asphalt Mixture ◽  
Test Method ◽  
Penetration Test ◽  
Triaxial Shear Test ◽  
Different Temperatures ◽  
Penetration Tests

With uniaxle penetration test method and Triaxial Shear method test, the shear strengths for asphalt mixture were analyzed. It turns out that the result of triaxial shear test is a little conservative than that of uniaxle penetration test. Then reasonable structure factor for shear strength should be considered by uniaxle penetration test. Uniaxle penetration tests at different temperatures revealed there were a linear correlation between shear strength and temperature.The asphalt was not the main fator of shear strength at high temperature.

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