Soil Shear Strength Characteristic in Slope Disintegration Area

2013 ◽  
Vol 353-356 ◽  
pp. 735-739
Author(s):  
Xiao Ming Zhang ◽  
Shu Wen Ding ◽  
Shuang Xi Li
Keyword(s):  
Shear Strength ◽  
Direct Shear Test ◽  
Shear Test ◽  
Clay Content ◽  
Scientific Basis ◽  
Soil Mechanic ◽  
Direct Shear ◽  
Soil Cohesion ◽  
Soil Shear Strength ◽  
The Relationship

Development of slope disintegration is close to soil mechanic characteristics such as shear strength indices. Soil grain diameter and water content were tested. Soil direct shear test was conducted to analyze the relationship between shear strength indices and the influencing factors. The experimental data indicate that clay content and the range affect soil cohesion value and the scope. Soil cohesion increases with bulk density before 1.6g/cm3. But it decreases when the bulk after that. The results could provide a scientific basis for control of slope disintegration.

Heat Effect Analysis of Buried Oil Pipeline in the Qinghai-Tibet Plateau

2014 ◽  
Vol 501-504 ◽  
pp. 211-217
Author(s):  
Wei Bo Liu ◽  
Wen Bing Yu ◽  
Xin Yi ◽  
Lin Chen
Keyword(s):  
Temperature Field ◽  
Frozen Soil ◽  
Operating Conditions ◽  
Tibet Plateau ◽  
Soil Mechanic ◽  
Insulation Layer ◽  
Effect Analysis ◽  
Oil Pipeline ◽  
Permafrost Table ◽  
Qinghai Tibet Plateau

The Geermu-Lasa oil pipeline was located in the Qinghai-Tibet Plateau permafrost regions. The building and operating of pipeline will change the temperature field of soil around it, which can lead to changes of frozen soil mechanic properties, and this will induces deformation or even fracture of pipeline. These phenomena will affect the normal transportation of oil. In this paper, temperature field around the pipelines were analyzed due to different pipe diameters and different insulation layer thicknesses in the way of finite element method. The rule of thawing and freezing of soil around the pipeline in an annual cycle was obtained. Artificial permafrost table variations under the pipeline were also obtained due to different operating conditions. For 30cm diameter pipeline with 7cm insulation layer, its artificial permafrost table depth change value is just 0.48m after 30-year running. These analysis results can provide references to the construction of the new Geermu-Lasa oil pipeline.

scholarly journals BEHAVIOR OF PINDOS LIMESTONE DURING HIGH SLOPE EXCAVATION. AN APPROACH TO INTERPRETE AND SIMULATE THE BEHAVIOR OF THE FORMATION USING SLOPE STABILTY ANALYSIS METHODS

2004 ◽  
Vol 36 (4) ◽  
pp. 1853
Author(s):  
A. Σφέικος ◽  
Θ. Στιμάρατζης ◽  
A. Κίλιας ◽  
Β. Χρηστάρας
Keyword(s):  
Safety Factor ◽  
Dynamic Equilibrium ◽  
Stable State ◽  
Soil Mechanic ◽  
River Diversion ◽  
The Road ◽  
Rock Formations ◽  
Geotechnical Characteristics ◽  
Slope Excavation ◽  
The Stability

The Acheloos river diversion project includes also works which improve the condition of the infrastructure network in the area. One of them was the improvement of a section at the Mouzaki - Arta national road. The road is developed through geological formations of the Pindos Zone. In the Argithea area, Karditsa County, it cuts through Cretaceous limestone bearing Calpionella. This formation develops high and steep slopes, over 50 m high. It consists of thin to medium bedded limestone, showing locally chert intercalations, and gradational transition to siliceous limestone. Thin silt or clay layers separate bedding. The formations is strongly folded and intensively jointed. The initial design proposed the construction of a slope with H:V relationship of 1:4 and benches every 20 m. The designed geometry was during and soon after excavation destroyed, due to sliding of rock particles. A new geometry was developed possessing a more stable state of dynamic equilibrium. Our task is to investigate and simulate the behavior of this formation. Based on data from both laboratory analysis and literature we ascribed the limestone formation values for its geotechnical properties. Using these values we estimate the values for the Safety Factor for the geometrical features of the slope. We control the stability of the slope using both rock mechanics and soil mechanic methods. The results point that rock formations, like the Cretaceous limestone which exhibit variation in their composition, and high contrast between the geotechnical characteristics values of the composing elements, may be considered as a material with soil properties. The Safety Factor calculation using these assumptions for the above mentioned slope, resulted a geometry close to the one developed. Therefore we conclude that such rock material and formations may successfully be simulated as materials with soil geotechnical behavior.

scholarly journals Excellent Performance of Earth Dams under Resonance Motion Using Isolator Damping Layer

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Behrouz Gordan ◽  
Azlan Adnan
Keyword(s):  
Scale Parameter ◽  
Free Vibration Analysis ◽  
Dominant Frequency ◽  
Earth Dam ◽  
Soil Mechanic ◽  
Seismic Zone ◽  
River Sand ◽  
Earthquake Effect ◽  
Small Models ◽  
Thickness Layer

The effect of blanket layer using isolator damping layer (IDL) between river sand foundation and short embankment to remove damage under severe earthquake was investigated in the present study. In case of numerical analysis by ANSYS program, dominant frequency (DF) was computed by free vibration analysis. Soil mechanic tests for thirteen samples to design IDL formula were carried out. In terms of critical condition for earthquake effect such as resonance, five physical small models were tested using vibrator table under the dominant frequency with scale parameter 1/100. As a result, dam was significantly damaged without blanket layer IDL. In order to reduce damage, the best performance was observed using blanket layer (IDL) when this layer was expanded below the reservoir region. The reinforced thickness layer size is one-fourth of dam height. This method is a novel suggestion for earth dam design in seismic zone.

scholarly journals STUDI PENURUNAN SEDIMEN KUARTER DI PERAIRAN CIREBON, PROPINSI JAWA BARAT

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Kris Budiono ◽  
Purnomo Raharjo
Keyword(s):  
Engineering Geology ◽  
Soil Mechanic ◽  
Quaternary Sediments ◽  
Test Analysis ◽  
Long Period ◽  
Key Word ◽  
Allowable Bearing Capacity ◽  
Soil Settlement ◽  
Recent Sediments ◽  
Total Sediment

Penelitian ini lebih difokuskan dalam mengaplikasikan data geologi teknik untuk menganalisis kemungkinan potensi penurunan sedimen Kuarter apabila didirikan suatu bangunan laut. Secara umum litologi daerah penelitian diperkirakan terdiri dari sedimen berumur Plistosen sampai Kuarter Data yang dipergunakan adalah data hasil pemboran teknik di laut dengan uji SPT dan hasil analisa laboratorium mekanika tanah. Berdasarkan pada perhitungan nilai SPT untuk setiap tiang pancang menunjukkan bahwa nilai daya dukung dijinkan (Qa) adalah 83,726 ton. Perkiraan nilai penurunan (St) adalah 0,992 cm atau 0,390 inci. Hasil perhitungan untuk dimensi dermaga yang direncanakan memperlihatkan bahwa beban total yang terjadi pada dermaga (q) adalah 2,18 ton/m2. Potensi penurunan lapisan tanah berdasarkan hasil uji laboratorium adalah 2,35 cm. Lamanya penurunan untuk terjadinya konsolidasi 10% adalah 94,81 hari (3,16 bulan), konsolidasi 20% adalah 367,41 hari (1,06 tahun), konsolidasi 50% adalah 2334,81 hari (6,39 tahun) dan konsolidasi 90% adalah 100503,7 hari (27,54 tahun). Berdasarkan kondisi tersebut di atas, menunjukan bahwa daerah penelitian memiliki potensi penurunan kecil dan dalam dalam waktu yang relatif lama. Kata kunci : geologi teknik, penurunan, bangunan laut, perairan Cirebon The aim of the study is mainly to apply the engineering geological data for analyzing the settlement potency of Quaternary sediments if the sea construction is built. In general, the litology in the study area consist of Plistocene to Recent sediments. The data used in this study are the offshore cores, namely, the SPT test and soil mechanic analyses. The SPT values of each pile shows that the allowable bearing capacity value is 83,726 ton. The estimation of settlement value ((St) is 0,992 cm or 0,390 inches. The total sediment loaded at the port (q) is 2,18 ton/m2, whereas based on the laboratory test analysis, it shows that the potential of soil settlement layer is 2,35 cm. The settlement period for 10% of consolidation is 94,81 days (3,16 months), 20% of consolidation is 367,41 days (1,06 years), 50% of consolidation is 2334,81 days (6.39 years), and 90% of consolidation is 100503,7 days (27.54 years). The above conditions indicate that the settlement in the study area is under going subsidence in small potential and in relatively long period. Key word : engineering geology, settlement, offshore structur, Cirebon waters

scholarly journals SPATIAL VARIABILITY OF RESISTANCE TO PENETRATION IN SOIL UNDER SUGARCANE CROPS WITH DIFFERENT HARVEST METHODS

2020 ◽  
Vol 33 (2) ◽  
pp. 480-489
Author(s):  
MAIRA DA CUNHA SOUZA ◽  
FLAVIO PEREIRA DE OLIVEIRA ◽  
JOSÉVALDO RIBEIRO SILVA ◽  
ADRIANA FERREIRA MARTINS ◽  
PEDRO LUAN FERREIRA DA SILVA
Keyword(s):  
Spatial Variability ◽  
Spherical Model ◽  
Intersection Point ◽  
North Coast ◽  
Soil Mechanic ◽  
Harvest Management ◽  
Soil Layers ◽  
The North ◽  
Undisturbed Samples ◽  
Resistance To Penetration

ABSTRACT The objective of this work was to evaluate the spatial variability of resistance to penetration in soil under sugarcane crops subjected to different harvest methods in the North Coast microregion of the state of Paraiba, Brazil. The study was conducted in a Typic Hapludult under sugarcane crops, at the farms Santa Emília-II and Maria da Luz-I of the company Miriri Food and Bioenergy S/A, in the municipalities of Rio Tinto and Capim, respectively, state of Paraíba, Brazil. Three sugarcane areas with different harvest methods (manual, mechanized, and manual/mechanized) were selected. The sampling was done in plots of 100 × 100 m, using a grid of 20 × 20 m, covering planting rows and interrows; each intersection point of the grid was georeferenced, and the soil mechanic resistance to penetration was evaluated with the aid of an impact penetrometer (IAA/Planalsucar-Stolf) up to the depth of 0-0.6 m. Soil disturbed and undisturbed samples from the 0.0-0.1 and 0.1-0.2 m layers were collected for analyses of soil moisture, texture, clay dispersed in water, flocculation degree. A pure nugget effect was found in the 0.0-0.1 and 0.4-0.5 m soil layers in the rows of the areas with manual/mechanized harvest. The spherical model was found for most conditions evaluated. The results for the areas were similar, with amplitude of 25-49 m, indicating that the harvest management had no effect on the soil resistance to penetration. No compacted areas were found, and the spatial dependency of the resistance to penetration was characterized as moderate to strong.

scholarly journals KARAKTERISTIK ENDAPAN SEDIMEN PANTAI TERHADAP PENGARUH LIQUIFAKSI DI KAWASAN PESISIR PANGANDARAN DAN SEKITARNYA, KABUPATEN CIAMIS, JAWA BARAT

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Kris Budiono ◽  
Purnomo Raharjo
Keyword(s):  
Void Ratio ◽  
Ground Surface ◽  
Soil Mechanic ◽  
Geological Hazards ◽  
Survey Area ◽  
Ground Acceleration ◽  
Richter Scale ◽  
Simplified Procedure ◽  
Sand And Gravel ◽  
Critical Void

Liquifaksi adalah salah satu bencana geologi yang berhubungan dengan kegempaan, dimana tekanan pori dalam tanah atau sedimen mengalami peningkatan akibat getaran, sehingga mengakibatkan aliran air ke arah permukaan tanah. Liquifaksi umumnya terjadi pada dataran rendah termasuk kawasan pesisir. Daerah penelitian yang terletak di sekitar pantai Pangandaran dan Parigi terdiri dari endapan lempung, lanau, pasir dan kerikil yang bersifat lepas dan jenuh air, secara regional sering dipengaruhi oleh kekuatan gempa antara 5,5 – 6 skala Richter dengan percepatan tanah antara 150 – 200 mgal. Kondisi seperti ini apabila terjadi gempa sangat memungkinkan untuk terjadi liquifaksi. Berdasarkan hasil perhitungan secara kuantitatif nisbah pori kritis, tidak semua lokasi penelitian akan mengalami liquifaksi pada percepatan permukaan 150 – 200 mgal. Berdasarkan nilai tumbukan SPT yang dipakai untuk analisis “simplified procedure”, daerah penelitian secara umum relatif kecil terhadap bahaya liquifaksi. Namun demikian berdasarkan korelasi antara sifat mekanik tanah dengan nilai SPT, pada kedalaman 0 – 8 m terdapat lapisan sedimen yang cukup rentan terhadap liquifaksi. Kata kunci: Liquifaksi,sedimen pantai,Pangandaran Liquefaction is one of many geological hazards related to an earthquake, where the void ratio pressure in soil or sediment will increase due to the vibration, that causing water flow up to the ground surface. Generally liquefaction is occurred in the low lying areas including coastal zone. The survey area located in the Pangandaran and Parigi coasts, is consisted of clay, silt, sand and gravel, of loose and saturated properties, generally is frequently influenced by 5,5 – 6 Richter scale of earthquake strength with the ground acceleration between 150 – 200 mgal. The liquefaction will be occurred in this condition if there is an earthquake. Based on the quantitatively calculation of critical void ratio, the liquefaction at ground acceleration of 150 – 200 mgal will not be occurred at all of the survey area. Based on the number of blows of SPT which is used for simplified procedure analysis, it shows that the study area is less influenced by the liquefaction. Nevertheless , based on the correlation between soil mechanic properties and SPT value, there is potential liquefiable sediments layer between the depth of 0 – 8 meters. Key words: liquefaction, coastal sediment, Pangandaran

Research on Teaching Method Reformation and Practice of Soil Mechanics

2011 ◽  
Vol 271-273 ◽  
pp. 1880-1883
Author(s):  
Zhi Hong Zhang ◽  
Cheng Shun Xu
Keyword(s):  
Teaching Methods ◽  
Civil Engineering ◽  
Teaching Method ◽  
Soil Mechanics ◽  
Soil Mechanic ◽  
Research On Teaching ◽  
Basic Course ◽  
New Situation

The soil mechanic course acts as a professional basic course of civil engineering. In recent years, we have made a better teaching effect by enriching teaching contents constantly and improving the teaching methods and means, but under the new situation there still exists certain shortage and weakness that need to strengthen. Based on the experience in teaching the author has putted forward the main problems existing in the teaching of soil mechanics course. What’s more, the specific suggestions on teaching reformation and practice have been suggested.

scholarly journals Strength-Based and Wave-Based Liquefaction Characterization

2006 ◽  
Vol 321-323 ◽  
pp. 1403-1406
Author(s):  
Gye Chun Cho ◽  
Jong Sub Lee
Keyword(s):  
Shear Strength ◽  
Wave Reflection ◽  
Spatial Scales ◽  
P Wave ◽  
Excess Pore Pressure ◽  
Soil Mechanic ◽  
S Wave ◽  
Before And After ◽  
Comprehensive Picture ◽  
Deep Layers

The purposes of this study are to analyze post liquefaction shear strength and to explore the potential use of wave-based techniques to monitor liquefaction and post liquefaction response. The first part presents a detailed analysis of triaxial test results to identify robust strength criteria. The second part documents experimental data on the characterization of liquefaction events with P-wave reflection imaging and S-wave trans-illumination techniques. The relevance of multiple coexisting temporal and spatial scales is highlighted. The following results are obtained: 1) the post liquefaction shear strength can be estimated within the framework of critical state soil mechanic; 2) the P-wave reflection images obtained before and after liquefaction represent the depression of the soil-water interface; 3) excess pore pressure migration from liquefied deep layers may cause zero-effective stress in dilative shallow layers. P-wave reflection is a valuable tool to monitor the evolution of subsurface structures and S-wave trans-illumination technique can be used to yield a comprehensive picture of the spatial evolution of liquefaction.

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