Influence of the Existing Cavern on the Stability of Adjacent Tunnel Excavation by Small-Scale Model Tests

A new way to construct artificial islands of sand is described. The method shows promise of considerable cost saving. The present high cost of island building is due to the difficulty of making underwater sand slopes steep. Simply dumping sand into the ocean results in slopes of from 12 to 15 horizontal to 1 vertical. These shallow slopes have enormous implications in terms of sand volume and cost. The sand can be tremied into place to form a steep-sided ring or bund. Handling large quantities of sand in this way is expensive. Small-scale model tests show that if the sand is mixed with certain chemicals the resulting 'cohesion' enables the sand to fall through seawater as a block, with little dispersion. Steep underwater slopes result. Low-cost, nontoxic (environmentally safe) chemicals were used in the experiment. Keywords: construction, artificial islands, sand, oceans, dredging.

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Pipeline plough performance in sand waves. Part 1: model testing

Canadian Geotechnical Journal ◽

10.1139/t09-077 ◽

2010 ◽

Vol 47 (1) ◽

pp. 49-64 ◽

Cited By ~ 9

Author(s):

Mark Fraser Bransby ◽

Michael Brown ◽

Andrew Hatherley ◽

Keith Lauder

Keyword(s):

Model Testing ◽

Model Tests ◽

Scale Model ◽

Soil Conditions ◽

Small Scale ◽

Offshore Pipelines ◽

Sand Waves ◽

Increased Risk ◽

Small Scale Model ◽

Spoil Heaps

Offshore pipelines are often buried in the seabed by ploughing a trench, placing the pipe at the base, and then backfilling. The ploughing operation is critical in terms of cost and project time, with increased risk due to uncertain soil conditions or geohazards. One problem that can be encountered is the presence of sand waves or megaripples on the seabed surface. This may affect the progress of the plough, prevent the plough from generating a level trench or modify the size of the spoil heaps for backfilling. These aspects have been investigated by conducting a series of small-scale model tests in the laboratory. These have revealed information about the plough kinematics and the resulting trench conditions when ploughing in sand waves with different wavelengths and amplitudes. It is shown that it may be possible to plough through regions of sand waves and estimate likely plough performance by knowing the sand wavelength and amplitude relative to the plough size.

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Wave overtopping and splash-up at seawalls with bullnose

Tạp chí Khoa học và Công nghệ Biển ◽

10.15625/1859-3097/20/3/15064 ◽

2020 ◽

Vol 20 (3) ◽

pp. 333-342

Author(s):

Le Hai Trung ◽

Dang Thi Linh ◽

Tang Xuan Tho ◽

Nguyen Truong Duy ◽

Tran Thanh Tung

Keyword(s):

Storm Surges ◽

Model Tests ◽

Scale Model ◽

Small Scale ◽

Wave Overtopping ◽

Run Up ◽

Coast Of Vietnam ◽

Small Scale Model ◽

Wall Interactions

Seawalls have been erected to protect hundreds of towns and tourism areas stretching along the coast of Vietnam. During storm surges or high tides, wave overtopping and splash-up would often threaten the safety of infrastructures, traffic and residents on the narrow land behind. Therefore, this study investigates these wave-wall interactions via hydraulic small scale model tests at Thuyloi University. Remarkably, the structure models were shaped to have different seaward faces and bullnoses. The wave overtopping discharge and splash run-up height at seawalls with bullnose are significantly smaller than those without bullnose. Furthermore, the magnitude of these decreasing effects is quantitatively estimated.

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Prototype measurements and small-scale model tests of wave overtopping at shallow rubble-mound breakwaters: the Ostia-Rome yacht harbour case

Coastal Engineering ◽

10.1016/j.coastaleng.2008.03.009 ◽

2009 ◽

Vol 56 (2) ◽

pp. 154-165 ◽

Cited By ~ 18

Author(s):

Leopoldo Franco ◽

Jimmy Geeraerts ◽

Riccardo Briganti ◽

Marc Willems ◽

Giorgio Bellotti ◽

...

Keyword(s):

Model Tests ◽

Scale Model ◽

Small Scale ◽

Wave Overtopping ◽

Rubble Mound ◽

Rubble Mound Breakwaters ◽

Small Scale Model

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Run-up on vertical piles due to regular waves: Small-scale model tests and prediction formulae

Coastal Engineering ◽

10.1016/j.coastaleng.2016.08.008 ◽

2016 ◽

Vol 118 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

Lisham Bonakdar ◽

Hocine Oumeraci ◽

Amir Etemad-Shahidi

Keyword(s):

Model Tests ◽

Scale Model ◽

Small Scale ◽

Regular Waves ◽

Run Up ◽

Small Scale Model

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Interference of Multiple Strip Footings on Sand Using Small Scale Model Tests

Geotechnical and Geological Engineering ◽

10.1007/s10706-008-9175-6 ◽

2008 ◽

Vol 26 (4) ◽

pp. 469-477 ◽

Cited By ~ 25

Author(s):

Jyant Kumar ◽

Manas Kumar Bhoi

Keyword(s):

Model Tests ◽

Scale Model ◽

Small Scale ◽

Strip Footings ◽

Small Scale Model

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Experimental Tests on a Small-Scale Model of a Mine Stope to Study the Behavior of Waste Rock Barricades during Backfilling

Minerals ◽

10.3390/min10110941 ◽

2020 ◽

Vol 10 (11) ◽

pp. 941

Author(s):

Mutaz Nujaim ◽

Tikou Belem ◽

Albert Giraud

Keyword(s):

Volumetric Strain ◽

Experimental Tests ◽

Waste Rock ◽

Scale Model ◽

Small Scale ◽

Downstream Face ◽

Solid Mass ◽

The Stability ◽

Reduced Scale ◽

Small Scale Model

This paper presents a reduced-scale physical model of a mine stope used to reproduce the underground stope backfilling practiced in some Canadian mines. The objective is to study the geomechanical behavior of the waste rock barricades in interaction with the mine backfill. The instrumentations, along with visual observations and preliminary results, are presented. The main results demonstrated that: (i) the stability of the barricade depends on its physical properties (e.g., size, location, particles gradation and compaction) and the frictional behavior at the barricade/drift walls interface, and (ii) for two backfill formulations, cemented and uncemented, prepared with 70% of solid mass concentration, the volumetric strain due to self-weight consolidation of the backfilled room was higher for uncemented backfill (16%) than for the cemented one (4.5%). In addition, the results highlighted the importance of using shotcrete around the downstream face of the barricade, mostly at the top, to close the gaps and bind the barricade particles, which improves its stability.

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Pillar-reinforcement technology beneath existing structures: Small-scale model tests

KSCE Journal of Civil Engineering ◽

10.1007/s12205-014-1392-3 ◽

2014 ◽

Vol 18 (3) ◽

pp. 819-826 ◽

Cited By ~ 2

Author(s):

H. J. Seo ◽

H. Choi ◽

K. H. Lee ◽

G. J. Bae ◽

I. M. Lee

Keyword(s):

Model Tests ◽

Scale Model ◽

Small Scale ◽

Existing Structures ◽

Small Scale Model

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Model Test of Ice-Structure Interaction

Volume 5: Polar and Arctic Sciences and Technology; CFD and VIV ◽

10.1115/omae2009-79780 ◽

2009 ◽

Cited By ~ 2

Author(s):

Fengwei Guo ◽

Qianjin Yue ◽

Xiangjun Bi ◽

Yuan Liu

Keyword(s):

Model Test ◽

Scaling Laws ◽

Interaction Model ◽

Test System ◽

Model Tests ◽

Scale Model ◽

Small Scale ◽

Structure Interaction ◽

Ice Loads ◽

Small Scale Model

Different scales of model tests for investigating ice-structure interaction due to ice crushing have been conducted, and successful experiences and conclusions obtained from previous tests are summarized. On the other hand, the uncertainties within current methodology of ice-structure interaction model tests are discussed. Considering the nature of dynamic ice loads, several main aspects which should be taken into account during design of model tests are analyzed, including layout of the test system, application of scaling laws, and techniques of making model ice sheet, etc. Decision can be made for each of these aspects according to objective of the test, and based on this viewpoint, a small scale model test system was designed and constructed, a series of model tests were conducted and the ice-structure interaction processes which are the same as prototype phenomenon were observed.

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