A centrifugal model test of microbial carbonate precipitation as liquefaction countermeasure

In view of the settlement problem of high loess-filled embankments themselves, with the reference of the 30m high embankment at K5 +536 of Lan Lin provincial expressway and by means of the centrifugal model test, the developing process of the settlement for embankment itself with time in different sections of embankment and the distribution laws of the settlement subjected from spatial effect in case of the different terrain conditions are studied. Compared with the actual measurement, the results show that: as far as the settlement of high-filled embankment itself is concerned, the settlement at the central part along the cross-section of embankment is larger than that at shoulder; When the stability of embankment is relatively poor because of the bigger slope ratio or faster speed of construction, the settlement at the shoulder caused by the lateral extrusion from the edge of embankment is larger; The settlement of embankment itself is approximately 0.5% -1% of the height of embankment, about 75% -85% of which occurred during the construction period and the remaining 15% -25% belongs to after construction. Furthermore, the 85% of the settlement belong to after construction will be completed within a year and about two years later the settlement tend to be stable; Owing to the affection of the spatial effect due to the valley terrain conditions, the settlement near the joint sites between the embankment and the gully is larger than that occurred in gentle slope and the central part of embankment. During the time of designing and construction for high-filled embankment, the location where the settlement influenced by the lateral extrusion and spatial effect should be paid attention to, so that, the security and stability of the embankment could be ensured.

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Theory of Microbial Carbonate Precipitation and Its Application in Restoration of Cement-based Materials Defects

Chinese Journal of Chemistry ◽

10.1002/cjoc.201090156 ◽

2010 ◽

Vol 28 (5) ◽

pp. 847-857 ◽

Cited By ~ 31

Author(s):

Chunxiang Qian ◽

Ruixing Wang ◽

Liang Cheng ◽

Jianyun Wang

Keyword(s):

Carbonate Precipitation ◽

Cement Based Materials ◽

Microbial Carbonate ◽

Microbial Carbonate Precipitation

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Significance of centrifugal model test in soil mechanics

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(75)91278-4 ◽

1975 ◽

Vol 12 (5-6) ◽

pp. 73

Keyword(s):

Model Test ◽

Soil Mechanics ◽

Centrifugal Model Test ◽

Centrifugal Model

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Sand Solidification through Microbially Induced Carbonate Precipitation for Erosion Control: Prospects in Bangladesh

Journal of Environmental Science and Natural Resources ◽

10.3329/jesnr.v9i1.30292 ◽

2016 ◽

Vol 9 (1) ◽

pp. 59-61

Author(s):

MNH Khan ◽

S Kawasaki ◽

MR Hassan

Keyword(s):

Erosion Control ◽

Precipitation Method ◽

Carbonate Precipitation ◽

Stiffness Properties ◽

Microbial Carbonate ◽

Microbial Carbonate Precipitation ◽

Microbially Induced Carbonate Precipitation ◽

Strength And Stiffness ◽

Ureolytic Bacteria

Bio-cementation is a sand consolidation technology, in which ureolytic bacteria release carbonate from urea hydrolysis in the presence of an excess of calcium ions to form calcite (CaCO3) in-situ. Biocementation is to enhance the strength and stiffness properties of soil and rocks though microbial activity or products. This paper addressed the prospect of microbial carbonate precipitation for erosion control in Bangladesh. Bacterial CaCO3 precipitation under appropriate conditions is a general phenomenon where the ureolytic bacteria uses urea as an energy source and produces ammonia which increases the pH in the environment and generates carbonate, causing Ca2+ and CO32- to be precipitated as CaCO3. This CaCO3 join sand particles and forms rocklike materials that auto-repairs by means of sunlight, seawater, and bacteria as microbially induced carbonate precipitation method. These rock particles when produced artificially is called artificial rock and has the potentiality to protect coastlines from erosion.J. Environ. Sci. & Natural Resources, 9(1): 59-61 2016

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Research On The Buttress-Warehouse Retaining Wall Based On Centrifugal Model Test

Proceedings of the 2017 3rd International Forum on Energy, Environment Science and Materials (IFEESM 2017) ◽

10.2991/ifeesm-17.2018.95 ◽

2018 ◽

Author(s):

Ying Nie ◽

Xuepeng Ling ◽

Fenghan Hu ◽

Qingsong Zhang ◽

Xiaofeng Zhao ◽

...

Keyword(s):

Model Test ◽

Retaining Wall ◽

Centrifugal Model Test ◽

Centrifugal Model

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Research on Application of Multi-Channel Selector in Centrifugal Model Test of Anchoring Slope by Frame Beam

Frontiers in Earth Science ◽

10.3389/feart.2021.757724 ◽

2021 ◽

Vol 9 ◽

Author(s):

Junhui Zhang ◽

Feng Li ◽

Shiping Zhang ◽

Jiankun Zhou ◽

Houming Wu

Keyword(s):

Model Test ◽

Effective Means ◽

Acquisition System ◽

Centrifugal Model Test ◽

Geotechnical Centrifuge ◽

Alpine Regions ◽

Sensor Signals ◽

One To One ◽

Centrifugal Model ◽

Centrifugal Test

An anchoring frame beam is a very common form of support for reinforced slopes, especially in alpine regions. Centrifugal tests have proved to be an intuitive and effective means of investigating the mechanism of action of frame beams. However, the data acquisition system of the geotechnical centrifuge in service has the problem of a small number of acquisition channels. A multi-channel selector based on the existing acquisition system was proposed, designed, processed, and manufactured, and it was debugged, tested, and applied in a no-load centrifugal test, static pressure model test, and centrifugal model test. The results show that the acquisition mode of the multi-channel selector connected with a maximum of 288 sensors has been changed from “one-to-one” to “one-to-many”. Its influence on various sensor signals is negligible. The multi-channel selector can work normally, which communicates and feeds back with the remote controller in the 1–120 g no-load centrifugal test. In the static load model test, 162 sensor signals were well collected through it. And only 51 channels were used to effectively obtain the signals of 187 sensors in a 70 g centrifugal model test of an anchoring slope with a frame beam. The multi-channel selector can be successfully applied in different use environments, saving time and reducing the cost of obtaining a single set of data.

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