In Situ Test on Cooling Effectiveness of Air Convection Embankment with Crushed Rock Slope Protection in Permafrost Regions

2005 ◽  
Vol 19 (2) ◽  
pp. 38-51 ◽  
Author(s):  
Sun Zhizhong ◽  
Ma Wei ◽  
Li Dongqing
Keyword(s):  
Rock Slope ◽  
Crushed Rock ◽  
Cooling Effectiveness ◽  
In Situ Test ◽  
Air Convection ◽  
Permafrost Regions

Construction Technology of Geogrid with Simplified Wrapped Face to Reinforce Swelling Rock Slope

2011 ◽  
Vol 261-263 ◽  
pp. 1690-1693
Author(s):  
Feng Yi Tan ◽  
Rong Hua Zou ◽  
Han Bing Hu ◽  
Zu Kai Lin
Keyword(s):  
Rock Slope ◽  
Layer By Layer ◽  
Construction Technology ◽  
In Situ Test ◽  
Whole Process ◽  
Test Region ◽  
North Water ◽  
Main Canal ◽  
Swelling Rock

The swelling rock slope reinforced by geogrid with wrapped face was one of reinforced methods in the swelling rock test region of main canal in South-to-North Water Division Project, the key step was the geogrid with wrapped face in layer by layer, which was not only the core step to make sure the reinforced swelling rock slope with geogrid as a integrality, but also the most complex, time consuming and cost in the whole process. From the in situ test, the construction technology and related construction parameters of geogrid of simplified face to reinforce the swelling rock slope was obtained, in which the construction of geogrid with wrapped face was optimized, the construction progress was improved and its cost was reduced, which contributed to the generalization and application of geogrid with simplified wrapped face to reinforce swelling rock slope in the middle-route of South-to-North Water Division Project, meanwhile, it was provided as a references for similar engineering.

Air Convection Embankment for Roadways: Field Experimental Study in Alaska

2003 ◽  
Vol 1821 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Steve Saboundjian ◽  
Douglas J. Goering
Keyword(s):  
Cross Section ◽  
Crushed Rock ◽  
Mean Annual Temperature ◽  
Foundation Soil ◽  
Cooling Effectiveness ◽  
Air Convection ◽  
Thaw Consolidation ◽  
Control Section ◽  
Temperature Offset ◽  
Measurement Period

During 1996—1997, an experimental air convection embankment (ACE) was constructed in Fairbanks, Alaska, using very coarse [1- to 6-in (25- to 150-mm)], poorly graded, crushed rock fill material on top of icerich permafrost foundation. The highly permeable ACE installation was designed to test the cooling effectiveness of the ACE concept in an actual roadway project. Using thermistor sensor strings, temperature data were collected from the ACE test section and an adjacent control section. Results showed that the ACE technique can be used to generate a passive cooling effect. This effect manifested as a depression of mean annual temperature at the base of the ACE cross section compared with mean embankment surface temperatures. The data indicated that this thermal offset is on the order of 7°F (Δ = 4°C) for this installation. The measured data also showed that mean annual temperatures are generally near or above the freezing value in the upper portion of the ACE embankment but significantly below freezing at the base. The temperature offset caused a gradual cooling of the foundation soil beneath the embankment with maximum base temperatures that have decreased from more than 40°F (4.4°C) to near freezing during the 5-year measurement period. Within a few more years of operation, it is anticipated that the permafrost table will move up into the base of the ACE cross section, completely eliminating any seasonal thaw in the foundation soil below and thus preventing future subgrade thaw–consolidation.

scholarly journals Design and Application of an In Situ Test Device for Rheological Characteristic Measurements of Liquefied Submarine Sediments

2021 ◽  
Vol 9 (6) ◽  
pp. 639
Author(s):  
Hong Zhang ◽  
Xiaolei Liu ◽  
Anduo Chen ◽  
Weijia Li ◽  
Yang Lu ◽  
...  
Keyword(s):  
Yellow River ◽  
Rheological Characteristic ◽  
Yellow River Delta ◽  
Turbidity Currents ◽  
Rheological Characteristics ◽  
Submarine Landslides ◽  
Test Device ◽  
Offshore Area ◽  
In Situ Test

Liquefied submarine sediments can easily lead to submarine landslides and turbidity currents, and cause serious damage to offshore engineering facilities. Understanding the rheological characteristics of liquefied sediments is critical for improving our knowledge of the prevention of submarine geo-hazards and the evolution of submarine topography. In this study, an in situ test device was developed to measure the rheological properties of liquefied sediments. The test principle is the shear column theory. The device was tested in the subaqueous Yellow River delta, and the test results indicated that liquefied sediments can be regarded as “non-Newtonian fluids with shear thinning characteristics”. Furthermore, a laboratory rheological test was conducted as a contrast experiment to qualitatively verify the accuracy of the in situ test data. Through the comparison of experiments, it was proved that the use of the in situ device in this paper is suitable and reliable for the measurement of the rheological characteristics of liquefied submarine sediments. Considering the fact that liquefaction may occur in deeper water (>5 m), a work pattern for the device in the offshore area is given. This novel device provides a new way to test the undrained shear strength of liquefied sediments in submarine engineering.

scholarly journals In Situ Shear Test for Revealing the Mechanical Properties of the Gravelly Slip Zone Soil

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6531 ◽  
Author(s):  
Zongxing Zou ◽  
Qi Zhang ◽  
Chengren Xiong ◽  
Huiming Tang ◽  
Lei Fan ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Plastic Deformation ◽  
Shear Test ◽  
Slip Zone ◽  
Three Gorges Reservoir Area ◽  
Silty Clay ◽  
Sigmoid Function ◽  
In Situ Test ◽  
Deformation Stage

Slip zone soil is usually composed of clay or silty clay; in some special geological environments, it contains gravels, which make the properties of the slip zone soil more complex. Unfortunately, in many indoor shear tests, gravels are removed to meet the demands of apparatus size, and the in situ mechanical property of the gravelly slip zone soil is rarely studied. In this study, the shear mechanical property of the gravelly slip zone soil of Huangtupo landslide in the Three Gorges Reservoir area of China was investigated by the in situ shear test. The test results show that the shear deformation process of the gravelly slip zone soil includes an elastic deformation stage, elastic–plastic deformation stage, and plastic deformation stage. Four functions were introduced to express the shear constitutive model of the gravelly slip zone soil, and the asymmetric sigmoid function was demonstrated to be the optimum one to describe the relationship of the shear stress and shear displacement with a correlation coefficient of 0.986. The comparison between the in situ test and indoor direct shear test indicates that gravels increase the strength of the slip zone soil. Therefore, the shear strength parameters of the gravelly slip zone soil obtained by the in situ test are more preferable for evaluating the stability of the landslide and designing the anti-slide structures.

Sign in / Sign up

Export Citation Format

Share Document