Some geotechnical aspects of the Hyogo-ken Nanbu (Kobe) earthquake of January 17, 1995

1996 ◽  
Vol 23 (3) ◽  
pp. 778-796 ◽  
Author(s):  
W. D. Liam Finn ◽  
P. M. Byrne ◽  
S. Evans ◽  
T. Law
Keyword(s):  
Soil Structure ◽  
Large Scale ◽  
Ground Improvement ◽  
Lateral Spreading ◽  
Bridge Piers ◽  
Soil Conditions ◽  
Kobe Earthquake ◽  
Port Facilities ◽  
Underground Subway Station ◽  
Directivity Effects

A geological and seismological framework is provided for understanding the damage to structures resulting from soil conditions. The paper focusses on the large-scale failures of the quay walls in Kobe Port due to liquefaction, and contrasts the performance of structures in improved and unimproved ground. Soil–structure interaction problems such as pile foundations, bridge piers, lifelines, and an underground subway station are also described. These failures have important implications for seismic design in the Fraser Delta in British Columbia, which has the potential for extensive liquefaction during a major earthquake. Key words: ground motions, directivity effects, liquefaction, lateral spreading, seismic settlements, seismic damage, port facilities, ground improvement.

Seismic Performance of Improved Ground Sites during the 2010–2011 Canterbury Earthquake Sequence

2014 ◽  
Vol 30 (1) ◽  
pp. 111-129 ◽  
Author(s):  
Liam M. Wotherspoon ◽  
Rolando P. Orense ◽  
Mike Jacka ◽  
Russell A. Green ◽  
Brady R. Cox ◽  
...  
Keyword(s):  
Large Scale ◽  
Ground Improvement ◽  
Soil Improvement ◽  
Earthquake Sequence ◽  
Soil Conditions ◽  
Ground Failure ◽  
Canterbury Earthquake Sequence ◽  
Liquefaction Assessment ◽  
The City ◽  
Selection Of

The city of Christchurch and the surrounding region on the South Island of New Zealand are underlain by large areas of recent alluvial sediments and fills that are highly susceptible to liquefaction and seismic ground failure. Thus, the widespread liquefaction that occurred following the successive large-scale earth-quakes, with moment magnitudes (MW) ranging from 6.0 to 7.1 that struck the Canterbury region in 2010–2011 was expected. Prior to the series of earthquakes, soil improvement had been used at several sites to mitigate the anticipated damage. This paper reviews the performance of improved sites during the Canterbury earthquake sequence. The existing soil conditions at each site and the design of the ground improvement are discussed, together with descriptions of the post-earthquake damage observed. Moreover, liquefaction assessment within and surrounding a selection of the ground improvement zones is presented.

scholarly journals Global earthworm distribution and activity windows based on soil hydromechanical constraints

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Siul A. Ruiz ◽  
Samuel Bickel ◽  
Dani Or
Keyword(s):  
Soil Structure ◽  
Mechanistic Model ◽  
Biophysical Model ◽  
Ecosystem Functions ◽  
Soil Conditions ◽  
Agricultural Systems ◽  
Occurrence Patterns ◽  
Additional Constraints ◽  
Earthworm Activity ◽  
Good Agreement

AbstractEarthworm activity modifies soil structure and promotes important hydrological ecosystem functions for agricultural systems. Earthworms use their flexible hydroskeleton to burrow and expand biopores. Hence, their activity is constrained by soil hydromechanical conditions that permit deformation at earthworm’s maximal hydroskeletal pressure (≈200kPa). A mechanistic biophysical model is developed here to link the biomechanical limits of earthworm burrowing with soil moisture and texture to predict soil conditions that permit bioturbation across biomes. We include additional constraints that exclude earthworm activity such as freezing temperatures, low soil pH, and high sand content to develop the first predictive global map of earthworm habitats in good agreement with observed earthworm occurrence patterns. Earthworm activity is strongly constrained by seasonal dynamics that vary across latitudes largely due to soil hydromechanical status. The mechanistic model delineates the potential for earthworm migration via connectivity of hospitable sites and highlights regions sensitive to climate.

Application of Neural Network in Identifying Soil Strata by CPT or CPTU Data

2012 ◽  
Vol 170-173 ◽  
pp. 945-949
Author(s):  
Jun Hai Li
Keyword(s):  
Neural Network ◽  
Ground Improvement ◽  
Thin Layers ◽  
Slope Instability ◽  
General Regression Neural Network ◽  
Excess Pore Pressure ◽  
Soil Conditions ◽  
Penetration Test ◽  
Piezocone Penetration Test ◽  
Tip Resistance

In geotechnical engineering, assessment of the depth location of stratigraphic interfaces and the depth and thickness of thin layers can be critical in the design process. For example, stratigraphic interfaces can promote anisotropic soil strength response and potentially provide preferential slip planes that create slope instability. Similarly, the presence of thin, high permeability layers can alter groundwater flow regimes and rates of consolidation, which can hinder or accelerate methods of ground improvement. The piezocone penetration test (PCPT or CPTU) is an extension of the cone penetration test (CPT) and is able to measure cone tip resistance, sleeve friction and generated pore-water pressures simultaneously. The piezocone’s functionality is through the measured excess pore pressure profile, which reflects changes in the drainage conditions, and therefore soil conditions. In this paper the relationship between CPTU parameters and soil types and strata is analyzed, and the structure of a general regression neural network (GRNN) is designed, and the application program is programmed with MATLAB language. The results, identifying soil strata by CPTU, have confirmed that GRNN can be used to carry out the automatically identifying soil strata.

An experiment in the control of the ground water-level in a fen peat soil

1951 ◽  
Vol 41 (1-2) ◽  
pp. 149-162 ◽  
Author(s):  
H. H. Nicholson ◽  
G. Alderman ◽  
D. H. Firth
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Large Scale ◽  
Field Experiments ◽  
Peat Soil ◽  
Climatic Conditions ◽  
Ground Water Level ◽  
Effective Control ◽  
Soil Conditions ◽  
Local Soil

1. The methods of investigation of the effect of ground water-level on crop growth, together with tho field installations in use, are discussed.2. Direct field experiments are handicapped by the difficulties of achieving close control on a sufficiently large scale, due to considerable variations of surface level and depth of peat within individual fields and to rapid fluctuations in rainfall and evaporation. Many recorded experiments are associated with climatic conditions of substantial precipitation during the growing season.3. Seasonal fluctuations of ground water-level in Fen peat soils in England, in natural and agricultural conditions, are described.4. The local soil conditions are outlined and the implications of profile variations are discussed.5. The effective control of ground water-level on a field scale requires deep and commodious ditches and frequent large underdrains to ensure the movement of water underground with sufficient freedom to give rapid compensatory adjustment for marked disturbances of ground water-level following the incidence of heavy rain or excessive evaporation.6. A working installation for a field experiment in ordinary farming conditions is described and the measure of control attained is indicated.

scholarly journals Exploring economic and legal barriers to commercial aquaponics in the EU through the lens of the UK and policy proposals to address them

2021 ◽  
Author(s):  
Christopher Cammies ◽  
David Mytton ◽  
Rosemary Crichton
Keyword(s):  
Food Production ◽  
Large Scale ◽  
Nutrient Loss ◽  
Soil Conditions ◽  
Application Process ◽  
Organic Certification ◽  
Recirculating Aquaculture ◽  
Economic Barriers ◽  
The Uk ◽  
The Eu

AbstractAquaponics is a food production system which connects recirculating aquaculture (fish) to hydroponics (plants) systems. Although aquaponics has the potential to improve soil conditions by reducing erosion and nutrient loss and has been shown to reduce food production related carbon emissions by up to 73%, few commercial aquaponics projects in the EU and UK have been successful. Key barriers to commercial success are insufficient initial investment, an uncertain and complex regulatory environment, and the lack of projects operating on a large scale able to demonstrate profitability. In this paper, we use the UK as a case study to discuss the legal and economic barriers to the success of commercial aquaponics in the EU. We also propose three policies: (1) making aquaponics eligible for the new system of Environmental Land Management grants; (2) making aquaponics eligible for organic certification; and (3) clarifying and streamlining the aquaponics licence application process. The UK’s departure from the EU presents a unique opportunity to review agricultural regulations and subsidies, which in turn could provide evidence that similar reforms are needed in the EU.

scholarly journals Influence of Tillage on the Mollisols Physicochemical Properties, Seed Emergence and Yield of Maize in Northeast China

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 939
Author(s):  
Qiang Chen ◽  
Xingyi Zhang ◽  
Li Sun ◽  
Jianhua Ren ◽  
Yaru Yuan ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Physicochemical Properties ◽  
Northeast China ◽  
Soil Structure ◽  
Aggregate Stability ◽  
Maize Yield ◽  
Conventional Tillage ◽  
Soil Conditions ◽  
Emergence Period

Tillage practices are critical for sustaining soil quality necessary for successful crop growth and productivity, but there are only few studies for strip tillage (ST) in the Mollisols region of Northeast China at present. A long-term (≥10-year) study was carried out to investigate the influence of within the tilled row (IR) and between rows (BR) in ST (10-year), conventional tillage (CT, 14-year) and no tillage (NT, 14-year) treatments on soil physicochemical properties. Soil samples were taken in May of 2019 at 0–5, 5–10, 10–20 and 20–30 cm depths and used to analyze bulk density (BD), soil aggregate distribution and stability, and soil organic carbon (SOC). Meanwhile, our study also explored the differences in seed emergence, soil moisture, and temperature during the seed emergence period, and yield of maize (Zea mays L.) among the different treatments. Similar soil properties were observed between ST-BR and NT, which showed they had a significantly greater BD, >0.25 mm water stable aggregate content (WR0.25) (especially in the amount of >2 mm and 1–2 mm size proportion), aggregate stability, and SOC than ST-IR and CT-IR at a depth of 0–20 cm. By improving soil conditions of seedbed, ST-IR and CT-IR increased soil temperature above NT by 1.64 °C and 1.80 °C, respectively, and ST-IR had a slight greater soil moisture than CT-IR in the top 10 cm layer during the seed emergence period. Late maize seed emergence was observed NT in than ST-IR and CT-IR and the average annual yields in ST were slightly greater than NT and CT, but the differences were not significant. Our results also showed that CT-BR had a poor soil structure and lower SOC than other treatments at 0–30 cm depth. We conclude from these long-term experimental results that ST could improve soil water-heat conditions to promote seed germination, maintain soil structure, and increase the maize yield and it should be applied in the Mollisols region of Northeast China.

scholarly journals Effect of Lime and Soil Conditioners on Crop Yields and Soil Aggregation

1969 ◽  
Vol 41 (3) ◽  
pp. 179-188
Author(s):  
M. A. Lugo-López ◽  
J. A. Bonnet ◽  
R. Pérez-Escolar
Keyword(s):  
Large Scale ◽  
Crop Yields ◽  
Acid Soils ◽  
Aggregate Stability ◽  
Soil Conditions ◽  
Structural Units ◽  
Ratoon Crop ◽  
Synthetic Materials ◽  
Soil Conditioners ◽  
Plant Crop

Data are presented here on the effect of synthetic soil conditioners on aggregation and aggregate stability of acid Lares clay and on their effect, with or without lime, on the yields of sweetpotatoes, cotton, and corn. Three conditioners were used: Formulations 6 and 9 of Krilium, and Aerotil, dry form, each at the rates of 900, 1,800, and 3,600 pounds to the acre. There were 20 treatments: Check, lime, conditioners at three levels, and conditioners at the same three levels plus lime. The data presented indicate that these conditioners will stabilize soil structural units, but will not form them. Five crops were grown as a sequence: Sweetpotatoes, cotton, cotton (a ratoon crop), sweetpotatoes, and corn. All crops, except the cotton ratoon, showed some response to the application of soil conditioners. Sweetpotato, a root crop, was more responsive; but the cotton plant crop responded also to stabilized good structural soil conditions. The largest crop responses measured were in the limed treatments. Increases attributable to lime were obtained either in the presence or absence of synthetic soil conditioners. Liming and rational fertilization seems to be the key to increased productivity in some acid soils of Puerto Rico. The synthetic materials do not have practical possibilities in large-scale farming.

scholarly journals The Gujarat, West India, earthquake (Jan 26th 2001). A geodynamic event in an intraplate compressional regime?

2001 ◽  
Vol 34 (4) ◽  
pp. 1405
Author(s):  
Γ. Δ. ΔΑΝΑΜΟΣ ◽  
Ε. Λ. ΛΕΚΚΑΣ ◽  
Σ. Γ. ΛΟΖΙΟΣ
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Indian Subcontinent ◽  
Plate Boundary ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Lateral Spreading ◽  
Tectonic Deformation ◽  
Epicentral Area ◽  
Surface Ruptures

The Jan. 26, 2001, Ms=7.7 earthquake occurred in Gujarat region of W. India, which lies 200-400 Km away from the active plate boundary zone, between the Indian subcontinent and the Asian plate, along the India-Pakistan border and the Himalayan belt. An Ms=7.7±0.2 earthquake also occurred in the same region in 1819. A zone of co-seismic E-W surface ruptures, 30-40 Km long and 15-20 Km wide, observed near the epicentral area and seems to be associated with pre-existing reverse faults and thrust folds, which were partially reactivated during the recent earthquake. Except the reverse vertical displacement a significant right lateral displacement was also observed along these E-W surface ruptures. This Ms=7.7 seismic event has been also accompanied by a large scale flexural-slip folding, as the absence of significant co-seismic fault displacement and fault scarp shows. This type of compressional tectonic deformation is also confirmed by the focal mechanism of the earthquake and the seismo-tectonic "history" of the area. The NW-SE open cracks, also observed along the same zone, are associated with the right lateral horizontal displacement of the reactivated fault (or branch faults) and the development of local extensional stress field in the huge anticlinic hinges of the co-seismic flexural-slip folds. A large number of ground ruptures, failures and open cracks are also associated with extensive sand boils, liquefaction phenomena and lateral spreading.

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