The Liquefaction Risk Analysis of Fine Sand Filling Subgrade

2011 ◽  
Vol 138-139 ◽  
pp. 668-672
Author(s):  
Hai Xia Zhang ◽  
Yu Feng Bai ◽  
Yue Jing Lv
Keyword(s):  
Soft Soil ◽  
River Estuary ◽  
High Strength ◽  
Fine Sand ◽  
High Water ◽  
Bridge Engineering ◽  
Fine Grain ◽  
Single Structure ◽  
Earthquake Load ◽  
Environment Experiment

It is signality for the Yangtse River estuary fine sand filling the highway subgrade which accounting for the lacking of filler and protecting along the line environment. Experiment results indicate that the sand has high strength, low compressibility, and good water stability. But the fine sand has some characteristics as grain uniformity, badness gradation, single structure, and the fine grain, and the fine sand filling subgrade is built on the soft soil foundation with high water table, so it is hidden troubles for the fine sand filling subgrade extending and application whether it can liquefy under the tempestuous earthquake load. The paper establish the liquefaction condition, carry through the liquefaction experiments and analysis the subgrade liquefaction risk relying on the Chong Ming connection engineering of Changjiang tunnel and bridge engineering. The analysis results indicate that the yangtse river estrary fine sand cannot liquefy with 7 class earthquake load, and it has no liequefaction conditions. So the subgrade has low liquefaction risk, and can be widely application.

scholarly journals Enhanced Water Resistance of Recycled Newspaper/High Density Polyethylene Composite Laminates via Hydrophobic Modification of Newspaper Laminas

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 421
Author(s):  
Binwei Zheng ◽  
Weiwei Zhang ◽  
Litao Guan ◽  
Jin Gu ◽  
Dengyun Tu ◽  
...  
Keyword(s):  
Stearic Acid ◽  
Photoelectron Spectroscopy ◽  
Composite Laminates ◽  
High Density Polyethylene ◽  
Water Resistance ◽  
Laminated Composite ◽  
High Strength ◽  
High Water ◽  
High Density ◽  
X Ray

A high strength recycled newspaper (NP)/high density polyethylene (HDPE) laminated composite was developed using NP laminas as reinforcement and HDPE film as matrix. Herein, NP fiber was modified with stearic acid (SA) to enhance the water resistance of the NP laminas and NP/HDPE composite. The effects of heat treatment and SA concentration on the water resistance and tensile property of NP and composite samples were investigated. The chemical structure of the NP was characterized with X-ray diffractometer, X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectra techniques. The surface and microstructure of the NP sheets were observed by scanning electron microscopy. An expected high-water resistance of NP sheets was achieved due to a chemical bonding that low surface energy SA were grafted onto the modified NP fibers. Results showed that the hydrophobicity of NP increased with increasing the stearic acid concentration. The water resistance of the composite laminates was depended on the hydrophobicity of the NP sheets. The lowest value of 2 h water absorption rate (3.3% ± 0.3%) and thickness swelling rate (2.2% ± 0.4%) of composite were obtained when the SA concentration was 0.15 M. In addition, the introduction of SA can not only enhance the water resistance of the composite laminates, but also reduce the loss of tensile strength in wet conditions, which shows potential in outdoor applications.

Design of a novel HSLA steel with a combination of high strength (140–160 ksi) and excellent toughness

2021 ◽  
Vol 112 (10) ◽  
pp. 800-811
Author(s):  
Mehdi Soltan Ali Nezhad ◽  
Sadegh Ghazvinian ◽  
Mahmoud Amirsalehi ◽  
Amir Momeni
Keyword(s):  
Impact Toughness ◽  
Yield Strength ◽  
Hsla Steel ◽  
Charpy Impact ◽  
High Strength ◽  
Controlled Rolling ◽  
The Other ◽  
Grain Structure ◽  
Charpy Impact Toughness ◽  
Fine Grain

Abstract Three steels were designed based on HSLA-100 with additional levels of Mn, Ni, Cr and Cu. The steels were prepared by controlled rolling and tempered at temperatures in range of 550–700°C. The continuous cooling time curves were shifted to longer times and lower temperatures with the increased tendency for the formation of martensite at lower cooling rates. The microstructures revealed that controlled rolling results in austenite with uniform fine grain structure. The steel with the highest amount of Mn showed the greatest strength after tempering at 750 °C. The top strength was attributed to the formation of Cu-rich particles. The steel with 1.03 wt.% Mn, tempered at 650 °C exhibited the best Charpy impact toughness at –85°C. On the other hand, the steel that contained 2.11 wt.% Mn and tempered at 700 °C showed the highest yield strength of 1 097.5 MPa (∼159 ksi) and an impact toughness of 41.6 J at –85°C.

scholarly journals Effects of High Plasticity and Expansive Clay Stabilization with Lime on UCS Testing in Several Conditions

2021 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Soewignjo Agus Nugroho ◽  
Gunawan Wibisono ◽  
Andarsin Ongko ◽  
Avrilly Zesthree Mauliza
Keyword(s):  
Soil Stabilization ◽  
Soft Soil ◽  
Fine Powder ◽  
High Water ◽  
Liquid Limit ◽  
Clay Soils ◽  
High Water Content ◽  
High Plasticity ◽  
Expansive Clay ◽  
Limit Value

Clay is a cohesive and very soft soil if it has high water content. To overcome this problem, clay soils with high plasticity need to be stabilized. The method of soil stabilization with lime is an alternative effort to improve soil that does not meet the standards. Lime reacts with groundwater so that it changes the property of the soil, reducing the stickiness and softness of the soil. Lime also functions to solidify (stabilize) and stabilize (stabilize) soil in the form of fine powder consisting of metals and inorganic mineral composition. This study aims to determine the effect of clay soils when carried out stabilization by using a limestone additive which varies in levels of mixture. The results showed that lime effective for the stabilization high plasticity and expansive clay by increasing the compressive strength value of UCS with lime content of 10% under curing conditions in 28 days and unsoaked by 319%, the liquid limit value reduced by 6% and the plastic limit value increased by 46%.

scholarly journals Evaluation of Microstructure and Selected Mechanical Properties of Laser Beam Welded S690QL High-Strength Steel

2018 ◽  
Vol 18 (3) ◽  
pp. 34-42 ◽  
Author(s):  
L. Tuz
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
High Strength Steel ◽  
High Strength ◽  
Fine Grain ◽  
Steel Material ◽  
Bainitic Structure ◽  
Haz Width ◽  
Quenching And Tempering ◽  
Softened Zone

AbstractThe paper presents results of microstructure and mechanical properties investigation of laser beam welded high-strength steel. Material for test was non-alloyed steel with yield strength of 690 MPa after quenching and tempering in delivery condition. Research carried out on the butt-welded joints shows fine-grain martensitic-bainitic structure of base metal and in the weld. Investigations of mechanical properties revealed the softened zone in HAZ where the hardness decrease without microstructural changes was observed. Moreover, an influence of softened zone and HAZ width on impact strength was observed where the occurrence of lower hardness led to fracture path deviation phenomenon.

scholarly journals SEDIMENT FRACTIONS AND ORGANIC MATERIALS IN THE DUMAI RIVER ESTUARY WATERS, RIAU, INDONESIA

2020 ◽  
Vol 1 (1) ◽  
pp. 66-71
Author(s):  
Syahril Nedi ◽  
Yolanda Manik ◽  
Elizal Elizal
Keyword(s):  
Organic Material ◽  
Organic Materials ◽  
River Estuary ◽  
Fine Sand ◽  
Chemical Factor ◽  
Purposive Sampling ◽  
Sediment Fraction ◽  
Mean Size ◽  
Negative Difference

The purpose of this researched was to analize the consistency of organic material and sediment fraction on estuary in dumai river. The research was with purposive sampling on four stutions. The analysis of sediment fraction in estuary in dumai river had been dominated by mud substract. The result mean size wened very fine sand, of consistency organic material is ranging 7,37 - 24,01 mg/l. The result sorting value wered poorly kurtosis value were ektremly leptokurtic, and skewness dominant value were negative. Difference of fine grafain and type of sediment on estuary in Dumai River had effect by physics and chemical factor.

scholarly journals Comparison of empirical models with intensively observed data for prediction salt intrusion in the Sumjin River estuary, Korea

2009 ◽  
Vol 6 (2) ◽  
pp. 1879-1905 ◽  
Author(s):  
D. C. Shaha ◽  
Y.-K. Cho
Keyword(s):  
River Discharge ◽  
Neap Tide ◽  
Spring Tide ◽  
River Estuary ◽  
High Water ◽  
Empirical Models ◽  
Length Scale ◽  
Salt Intrusion ◽  
Salinity Data ◽  
Comparative Results

Abstract. Intensive measurements of salt intrusion in the Sumjin River estuary were taken at high and low waters during both spring and neap tides in each season from August 2004 to April 2007. The estuary demonstrated partially- and well-mixed characteristics during the spring tide and stratified condition during the neap tide. The salt intrusion at high water varied from about 13.39 km in summer 2005 to 25.62 km in autumn 2006. The salt intrusion depended primarily on the freshwater discharges rather than those of spring-neap tidal oscillations. Analysis of three years of observed salinity data indicated that the salt intrusion length scale in the Sumjin River estuary was proportional to the river discharge to the −1/5 power. Five empirical models were applied to the Sumjin River estuary to explore the most suitable as an easy-to-use tool for prediction of the salt intrusion length as functions of the geometry, river discharge and tide. Comparative results showed that the Nguyen and Savenije (2006) model developed under both partially- and well-mixed estuaries yielded the most satisfactory results of all the models studied for computing the salt intrusion length in the Sumjin River estuary. Our study suggests that the model can generate reasonable results for stratified conditions also.

Experimental Investigation on HRBF500 RC Circular Pile under Low Cyclic Reversed Loading

2011 ◽  
Vol 105-107 ◽  
pp. 1250-1254
Author(s):  
Qian Fu ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Seismic Design ◽  
Seismic Behavior ◽  
High Strength ◽  
Skeleton Curve ◽  
Failure Patterns ◽  
Concrete Piles ◽  
Fine Grain ◽  
Steel Bars ◽  
Reversed Loading ◽  
Ductile Behavior

Six concrete piles reinforced with 500MPa fine-grain steel bars were tested under low cycle reversed loading to study the seismic behavior such as failure patterns, characteristics of hysteretic and skeleton curve. Three parameters, longitudinal reinforcement strength, reinforcement ratio and axial compression ratio were taken into consideration. The main failure patterns as well as hysteretic curve of those piles were obtained, and influence of each of the three parameters on the ductile behavior, ability of energy dissipation and law of strength degeneration were analyzed. The experimental results indicate that the mechanical behavior of reinforced concrete low cyclic reversed loading columns with fine grain high strength reinforcement is similar to normal reinforced columns. The concrete piles reinforced with 500MPa fine-grain steel bars show good seismic performance and 500MPa fine-grain steel bars can be used in seismic design.

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