Consolidation of unsaturated composite ground reinforced by permeable columns

2020 ◽  
Vol 125 ◽  
pp. 103706 ◽  
Author(s):  
Lei Wang ◽  
Annan Zhou ◽  
Yongfu Xu ◽  
Xiaohe Xia
Keyword(s):  
Composite Ground

scholarly journals Determination of the Sensitivity of a RapidEscherichia coli O157:H7 Assay for Testing 375-Gram Composite Samples

2000 ◽  
Vol 66 (9) ◽  
pp. 4149-4151 ◽  
Author(s):  
Wan-Ling Tsai ◽  
Cynthia E. Miller ◽  
Edward R. Richter
Keyword(s):  
Escherichia Coli ◽  
Sample Size ◽  
Ground Beef ◽  
Immunomagnetic Separation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa System ◽  
Composite Ground ◽  
Single Size ◽  
Composite Samples

ABSTRACT Both 25-g single-size ground beef samples and 375-g composite ground beef samples were tested by a method combining an immunomagnetic separation (IMS) technique with a sandwich enzyme-linked immunosorbent assay (ELISA) system (IMS-ELISA). The results demonstrated that IMS-ELISA could detect the target, Escherichia coliO157:H7, at the level of 10−1 CFU/g of sample in either the 25- or 375-g sample size.

Consolidation Theory for Composite Ground with Granular Columns Based on Different Calculation Models

2011 ◽  
Vol 261-263 ◽  
pp. 1534-1538
Author(s):  
Yu Guo Zhang ◽  
Ya Dong Bian ◽  
Kang He Xie
Keyword(s):  
Pore Water ◽  
Analytical Solutions ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Vertical Flow ◽  
Excess Pore Water Pressure ◽  
Consolidation Theory ◽  
Composite Ground ◽  
Granular Column ◽  
Excess Pore

The consolidation of the composite ground under non-uniformly distributed initial excess pore water pressure along depth was studied in two models which respectively considering both the radial and vertical flows in granular column and the vertical flow only in granular column, and the corresponding analytical solutions of the two models were presented and compared with each other. It shows that the distribution of initial excess pore water pressure has obvious influence on the consolidation of the composite ground with single drainage boundary, and the rate of consolidation considering the radial-vertical flow in granular column is faster than that considering the vertical flow only in granular column.

Research to build technological procedure for soft ground improvement using sea sand-cement-fly ash column

2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 1-9
Author(s):  
Thinh Duc Ta ◽  
Phuc Dinh Hoang ◽  
Thang Anh Bui ◽  
Trang Huong Thi Ngo ◽  
Diu Thi Nguyen ◽  
...  
Keyword(s):  
Fly Ash ◽  
Load Capacity ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soil Reinforcement ◽  
Soft Ground ◽  
Design Calculation ◽  
Sea Sand ◽  
Composite Ground ◽  
Soft Ground Improvement

Sea sand-cement-fly ash column technology for soft soil treatment is a new technology in the process of completing the theoretical basis, the experimental basis, and the construction of the ground treatment technological procedure. The paper presents the results of scientific research on design, calculation, construction, and acceptance of sea sand-cement-fly ash column. The scientific basis for the design of column is to consider the role of the column in composite ground, that is to use the column as soft ground improvement or soft soil reinforcement. The important parameters for the column design are: cement and fly ash content; column length; column diameter; number of columns; distance among columns; load capacity and settlement of composite ground. The sequence of steps of construction and acceptance of column includes: selection of construction equipment, preparation of construction sites, trial construction, official construction, evaluation of ground quality after treatment and preparation of document for acceptance.

Practical Method for the Pile Composite Ground under Flexible Foundation Based on Super-Substructure Interaction

2011 ◽  
Vol 250-253 ◽  
pp. 2575-2582
Author(s):  
Yong Fei Peng ◽  
Jian Lin Yu ◽  
Xiao Nan Gong ◽  
Wen Zhi Lv
Keyword(s):  
Analytical Model ◽  
Stress Ratio ◽  
Practical Method ◽  
Interactive System ◽  
Relative Movement ◽  
Foundation Soil ◽  
Composite Ground ◽  
Water Conservancy ◽  
Stress And Deformation ◽  
Flexible Foundation

The technology of the composite ground under a flexible foundation have been widely used in transportation, water conservancy and other departments, yet its theory of characterizing the behavior of the composite ground needs to be further researched. A simplified analytical model is presented, considering the above four parts which includes the flexible foundation, the cushion, the composite ground, and the underlying soils as an interactive system, allowing for the relative movement between piles and soils, and assuming different settlement of foundation soil at the same elevation. The force equilibriums of a typical element are established. And then, according to the compatibility of stress and deformation on the interfaces between these four components, the formulas on settlement and stress ratio of pile-soil, which is used to characterize the behavior of the composite ground, are derived.

Static response of fly ash columnar improved ground

2001 ◽  
Vol 38 (2) ◽  
pp. 276-286 ◽  
Author(s):  
A Porbaha ◽  
T BS Pradhan ◽  
T Kishida
Keyword(s):  
Fly Ash ◽  
Stress Concentration ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Triaxial Compression ◽  
Area Ratio ◽  
Stress Redistribution ◽  
Soft Ground ◽  
Compression Tests ◽  
Composite Ground

This study presents the results of a series of monotonic undrained triaxial compression tests on clay specimens improved by columnar reinforcement. The process of loading and stress redistribution of a fly ash – clay specimen (FCS), in comparison with a sand–clay specimen (SCS), is examined in terms of stress–strain characteristics, generation of excess pore-water pressure, effective and total earth pressures, development of stress concentration, and the normalized undrained shear strength of the improved soil. It was found, predictably, that the deviator stress of the composite specimens was influenced by the consolidation stress, replacement area ratio, and properties of the column material. The stress concentration at the top of the composite ground which depends on the loading stage reaches a peak after the consolidation state and is reduced due to stress redistribution between the column and the soft ground. In terms of improvement effects, the mean shear strengths of FCS and SCS relative to the clay specimen are three and seven times greater, respectively, for a replacement area ratio of 49%.Key words: composite ground, fly ash, soil improvement, soft ground, triaxial test.

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