Experimental investigation of compaction-grouted soil nails

2017 ◽  
Vol 54 (12) ◽  
pp. 1728-1738 ◽  
Author(s):  
Qiong Wang ◽  
Xinyu Ye ◽  
Shanyong Wang ◽  
Scott William Sloan ◽  
Daichao Sheng
Keyword(s):  
Large Scale ◽  
Scale Model ◽  
Interface Shear ◽  
Soil Nails ◽  
Soil Nail ◽  
Pull Out ◽  
Grouting Pressure ◽  
Large Scale Model ◽  
Ultimate Failure ◽  
Surrounding Soil

An innovative compaction-grouted soil nail was designed by injecting grout into a special latex balloon (grouting bag) to avoid bleeding and penetration of grout into the surrounding soil. A series of large-scale model tests was performed to study the surrounding soil responses due to grouting and the subsequent pull-out resistance of the soil nail. The experimental results show that grouting pressure plays an important role in the enhancement of the density and (or) strength of the surrounding soil. In addition, during the pull-out process, the compaction-grouted soil nail exhibits a strain-hardening behaviour without a yield point. This is a significant advantage of this new soil nail, indicating that it can enable soil masses to remain stable against a relatively large deformation before ultimate failure. The main factors behind the improvement of the pull-out resistance of the new soil nail are, first, the compaction–densification of the soil near the grouting bag due to grouting, resulting in the enhancement of the shear strength of the soil, and, second, the enlargement of the grouting bag, causing the increase of the interface shear and end resistance to the pull-out of the soil nail.

Influence of degree of saturation on soil nail pull-out resistance in compacted completely decomposed granite fill

2007 ◽  
Vol 44 (11) ◽  
pp. 1314-1328 ◽  
Author(s):  
Li-Jun Su ◽  
Terence C.F. Chan ◽  
Y.K. Shiu ◽  
Tony Cheung ◽  
Jian-Hua Yin
Keyword(s):  
Shear Strength ◽  
Degree Of Saturation ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Soil Nails ◽  
Soil Nail ◽  
Pull Out ◽  
Decomposed Granite ◽  
Soil Interface ◽  
Completely Decomposed Granite

The nail–soil interface shear strength is a key parameter in the design and stability assessment of soil nailing systems. A number of factors will influence the nail–soil interface shear strength. Among these factors, the degree of saturation (Sr) of the soil is an important one especially for permanent soil nail structures. To study the influence of Sr on soil nail pull-out shear resistance, a series of laboratory pull-out tests have been conducted on soil nails in compacted completely decomposed granite (CDG) fill prepared to different Sr. The tests were conducted using two specially designed pull-out boxes (with same specifications). In the near-saturated tests, a high Sr (about 98%) was achieved using two special features of the apparatus: a waterproof front cap and back-water pressure pipes at the bottom of the pull-out box. Test results showed that the nail–soil shearing plane migrated outwards into the soil when the Sr of the soil increased. Also, peak pull-out strengths of soil nails were strongly influenced by the Sr of the soil. Among the tested Sr, the highest values of peak pull-out shear strength were obtained at Sr values between 50% and 75%.

Numerical Simulation of Pressure Grouting in Soil Nail Pull-Out Tests

2007 ◽  
Vol 353-358 ◽  
pp. 1037-1040 ◽  
Author(s):  
Li Jun Su ◽  
Jian Hua Yin ◽  
Shan Yong Wang ◽  
Hong Jian Liao
Keyword(s):  
Three Dimensional ◽  
Cost Effective ◽  
Fe Model ◽  
Soil Nailing ◽  
Interface Shear ◽  
Soil Nail ◽  
Pull Out ◽  
Grouting Pressure ◽  
Current Design ◽  
Pressure Grouting

Soil nailing is a widely used technique for stabilizing slopes and excavations. In all current design methods, the nail-soil interface shear strength, that is, the pull-out resistance of a soil nail is an important parameter which controls the design and safety assessment of the soil nailing system. The pressure grouting is a cost effective method for increasing the soil nail pull-out resistance and in turn improving the performance of the nailed structure. In this paper, a three dimensional (3-D) finite element (FE) model for pull-out tests is established and verified by comparing simulated results with measured data. This model is then used to simulate the effect of grouting pressure on the soil nail pull-out resistance.

Experimental study on the pullout resistance of pressure-grouted soil nails in the field

2013 ◽  
Vol 50 (7) ◽  
pp. 693-704 ◽  
Author(s):  
Cheng-Yu Hong ◽  
Jian-Hua Yin ◽  
Hua-Fu Pei ◽  
Wan-Huan Zhou
Keyword(s):  
Water Content ◽  
Field Tests ◽  
Soil Samples ◽  
Soil Nails ◽  
Pullout Resistance ◽  
Soil Nail ◽  
Grouting Pressure ◽  
Overburden Stress ◽  
Drill Holes ◽  
Surrounding Soil

The pullout behaviour of cement-grouted soil nails, particularly in field conditions, is not yet fully understood. In this study, a series of tests was conducted to evaluate the pullout response of grouted soil nails in a field slope. A new innovative grouting packer system was developed to control the grouted length and maintain the cement grout pressure of the grouted part. By using the grouting packer system, a total of 10 soil nails placed at different soil depths were grouted with different pressures in the field. The pullout results of present field tests and a number of past laboratory tests indicate that the apparent coefficient of friction (ACF) decreases with the increase of overburden stress even though grouting pressure is applied. In addition, when the overburden stress is unchanged, the obtained ACF values in the field tests appear to increase almost linearly with the increase of grouting pressure. After the soil nails were completely pulled out of the ground, the surfaces of the soil nails and surrounding soil were examined. It is found that the water content of the soil samples at the soil–nail interfaces decrease substantially compared to the water content of soil samples in drill holes. Measurement results also show that the failure surfaces of soil nails shifted about 16 mm on average into the surrounding soil due to the application of grouting pressure.

scholarly journals STABILITY OF INTERLOCKED PATTERN PLACED BLOCK REVETMENTS

2012 ◽  
Vol 1 (33) ◽  
pp. 46 ◽  
Author(s):  
Fabian Gier ◽  
Holger Schüttrumpf ◽  
Jens Mönnich ◽  
Jentsje Van der Meer ◽  
Matthias Kudella ◽  
...  
Keyword(s):  
Large Scale ◽  
Wind Waves ◽  
Scale Model ◽  
Test Results ◽  
Friction Forces ◽  
Ship Waves ◽  
Pull Out ◽  
Large Scale Model ◽  
The Individual ◽  
Hydraulic Stability

Revetments protect the shorelines of coasts, estuaries and rivers against wind waves, ship waves, currents and ice attacks. The resistance of revetments basically depends on the properties of the cover layer. In the case of an interlocked pattern placed revetment the resistance essentially depends on the weight of the individual blocks, the friction forces and the interlocking force. In this study, extensive large scale model tests have been performed to assess the hydraulic stability of interlocked pattern placed revetments. The study shows test results due to deformations, wave loading and pull-out tests. Overall, the experimental results show a significant increase in the structural stability of the revetment against wave attack due to the interlocking system compared to traditional revetment elements.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

Effect of an Oscillating Flow Direction on Leading Edge Heat Transfer

1984 ◽  
Vol 106 (1) ◽  
pp. 222-228 ◽  
Author(s):  
M. L. Marziale ◽  
R. E. Mayle
Keyword(s):  
Heat Transfer ◽  
Strouhal Number ◽  
Large Scale ◽  
Flow Direction ◽  
Leading Edge ◽  
Periodic Variation ◽  
Scale Model ◽  
Transfer Rates ◽  
Large Scale Model ◽  
Turbulence Length

An experimental investigation was conducted to examine the effect of a periodic variation in the angle of attack on heat transfer at the leading edge of a gas turbine blade. A circular cylinder was used as a large-scale model of the leading edge region. The cylinder was placed in a wind tunnel and was oscillated rotationally about its axis. The incident flow Reynolds number and the Strouhal number of oscillation were chosen to model an actual turbine condition. Incident turbulence levels up to 4.9 percent were produced by grids placed upstream of the cylinder. The transfer rate was measured using a mass transfer technique and heat transfer rates inferred from the results. A direct comparison of the unsteady and steady results indicate that the effect is dependent on the Strouhal number, turbulence level, and the turbulence length scale, but that the largest observed effect was only a 10 percent augmentation at the nominal stagnation position.

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