scholarly journals Analytical method of forecasting the settlement of water-saturated soils over time

2018 ◽  
Vol 251 ◽  
pp. 04030
Author(s):  
Irina Yudina
Keyword(s):  
Pore Water ◽  
Function Method ◽  
Source Function ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Saturated Soils ◽  
Exponential Functions ◽  
Degree Of Consolidation ◽  
Water Saturated ◽  
Over Time

The paper deals with the formulation and solution of the consolidation problem for weak water-saturated soil bases by using exponential functions to describe the initial pore water pressure with zero boundary conditions on the surface of the base and at infinity. The solution of this problem was obtained in closed form by the source function method. Expressions are given for the pore water pressure and degree of consolidation, as well as an example of such calculation.

scholarly journals Implications of the principle of effective stress

2020 ◽  
Author(s):  
Gerd Gudehus
Keyword(s):  
Critical Phenomena ◽  
Pore Water ◽  
Effective Stress ◽  
Critical Points ◽  
Pore Water Pressure ◽  
Numerical Models ◽  
Water Pressure ◽  
Shear Bands ◽  
Triaxial Tests ◽  
Water Saturated

AbstractWhile Terzaghi justified his principle of effective stress for water-saturated soil empirically, it can be derived by means of the neutrality of the mineral with respect to changes of the pore water pressure $$p_w$$ p w . This principle works also with dilating shear bands arising beyond critical points of saturated grain fabrics, and with patterns of shear bands as relics of critical phenomena. The shear strength of over-consolidated clay is explained without effective cohesion, which results also from swelling up to decay, while rapid shearing of water-saturated clay can lead to a cavitation of pore water. The $$p_w$$ p w -neutrality is also confirmed by triaxial tests with sandstone samples, while Biot’s relation with a reduction factor for $$p_w$$ p w is contestable. An effective stress tensor is heuristically legitimate also for soil and rock with relics of critical phenomena, particularly for critical points with a Mohr–Coulomb condition. Therein, the $$p_w$$ p w -neutrality of the solid mineral determines the interaction of solid fabric and pore water, but numerical models are questionable due to fractal features.

Preconsolidation pressures in intertill glaciolacustrine clay near Blaine Lake, Saskatchewan

1988 ◽  
Vol 25 (4) ◽  
pp. 831-839 ◽  
Author(s):  
E. Karl Sauer ◽  
E. A. Christiansen
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Ice Thickness ◽  
Excess Pore Water Pressure ◽  
Stability Of Slopes ◽  
Preconsolidation Pressure ◽  
Insufficient Time ◽  
Degree Of Consolidation ◽  
Excess Pore

Soft, intertill, glaciolacustrine clays are of concern for stability of slopes and foundations. An intertill clay deposit between 32 and 54 m below the surface was continuously cored. Index properties were determined for 46 samples and 10 samples were tested on the oedometer. Stratigraphic evidence indicates that the glaciolacustrine clay (Blaine Lake Member), lying between the till of the Sutherland and Saskatoon groups, was glaciated three times. However, preconsolidation pressures of this intertill clay show the degree of consolidation is less than 20% based on a total stress from an estimated ice thickness extrapolated from the Cypress Hills. This low preconsolidation pressure suggests there was insufficient time for dissipation of excess pore-water pressure created by thickening of the advancing glacier. Key words: preconsolidation pressure, excess pore-water pressure, glaciers, intertill clay.

Offshore Sea Airport Revetment Structure Foundation Liquefaction Analysis

2013 ◽  
Vol 353-356 ◽  
pp. 2171-2176
Author(s):  
Jie Zhao ◽  
Gao Jie Yun ◽  
Gui Xuan Wang
Keyword(s):  
Dynamic Analysis ◽  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Total Stress ◽  
Treatment Methods ◽  
Ground Treatment ◽  
Over Time ◽  
Liquefaction Analysis

This Earthquake liquefaction analysis of total stress method is often used, but the total stress method does not consider the variation of pore water pressure and the process of development of the liquefaction over time. Using two perspectives which the total stress method and effective stress dynamic analysis given liquefied range of offshore airport foundation under the earthquake , and giving recommendations for ground treatment methods.

scholarly journals EVALUASI SETTLEMENT MENGGUNAKAN SURCHARGE PRELOADING DENGAN PVD PADA PROYEK DI BANDUNG SELATAN

2020 ◽  
Vol 3 (3) ◽  
pp. 911
Author(s):  
Michael Christopher Yapriadi ◽  
Inda Sumarli ◽  
Ali Iskandar
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Improvement ◽  
Soil Layers ◽  
Excess Pore Water Pressure ◽  
Surcharge Preloading ◽  
Improvement Method ◽  
Degree Of Consolidation ◽  
Excess Pore

The development in Indonesia continues to grow. Hence, the feasible land for construction is drastically decreased. However, some projects must be constructed on that kind of land. One solution to solve this problem is by using a soil improvement. A project in Bandung Selatan chose to apply Surcharge Preloading with PVD soil improvement method. This project used a combination of 9,2 metres surcharge preload and a 28 metres depth PVD, with triangular formation and 1,2 metres spacing. The soil improvement was finished after 548 days. This analysis aims to evaluate the settlement from the soil improvement result, which is 1,297 metres. This analysis uses a finite difference method program. The excess pore water pressure from the analysis result is 0,229 T/m2 on the 548th day. Therefore, these soil layers have possibilities to settle again in future. The 90% degree of consolidation settlement for this soil layers is 2,31 metres, which will be reached on the 813,4th days. It is suspected that there are some mistakes either during the soil improvement designing or the soil improvement process. Pembangunan di Indonesia terus berkembang. Akibatnya jumlah tanah yang baik untuk proyek konstruksi semakin menipis. Kendati demikian, ada kalanya suatu proyek harus dilaksanakan di lokasi tersebut. Salah satu solusi yang dapat ditempuh adalah dengan melakukan perbaikan tanah. Sebuah proyek di Bandung Selatan melakukan perbaikan tanah dengan metode Surcharge Preloading dengan PVD. Proyek ini menggunakan kombinasi antara timbunan setinggi 9,2 meter dan PVD sedalam 28 meter, dengan formasi segitiga yang dipasang dengan jarak antar PVD 1,2 meter. Perbaikan tanah dilakukan selama 548 hari. Analisis ini bertujuan melakukan evaluasi terhadap kurang maksimalnya penurunan di lapangan yang hanya mencapai 1,297 meter. Analisis dilakukan dengan bantuan program beda hingga. Berdasarkan hasil analisis, besarnya excess pore water pressure pada hari ke-548 adalah 0,229 T/m,2, sehingga lapisan tanah tersebut masih memiliki potensi untuk mengalami penurunan. Adapun penurunan konsolidasi 90% yang dapat terjadi sebesar 2,31 meter pada hari ke-813,4. Diduga terdapat kesalahan baik dalam perhitungan perencanaan awal ataupun saat pelaksanaan di lapangan.

scholarly journals Proof-of-concept for a probe to measure pore water pressure in oil-water saturated porous rock

2021 ◽  
Vol 198 ◽  
pp. 108183
Author(s):  
Anastasia Capotosto ◽  
Bruna de Carvalho Faria Lima Lopes ◽  
Alessandro Tarantino
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Proof Of Concept ◽  
Porous Rock ◽  
Oil Water ◽  
Water Saturated

scholarly journals Experimental evidence about misconception of Terzaghi's 1-D consolidation theory in terms of degree of consolidation

2019 ◽  
Vol 106 ◽  
pp. 01013
Author(s):  
Bartłomiej Szczepan Olek
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Behavior ◽  
Marine Clay ◽  
Fine Grained ◽  
Consolidation Theory ◽  
Fine Grained Soil ◽  
Degree Of Consolidation ◽  
The Relationship

Terzaghi's 1-D consolidation theory is commonly used for prediction of embankment settlement in soft fine-grained soil. Application of this theory is not always effective due to the simplifications of assumed soil behavior under load. This paper examines relationship between the degrees of consolidation determined by pore water pressure measured at the base of the sample and one-dimensional strain. Theoretically, this relationship should be unique, however experimental relationships correlating the degrees of consolidation are found to be non-linear. The article presents the results of multistage consolidation tests with pore water pressure measurements, carried out on intact and reconstituted deep marine clay. Consolidation tests were conducted with uniform stress distribution and single-sided drainage conditions. It was observed that the relationship between degrees of consolidation for intact and reconstituted samples largely divergent from theoretical unique line.

scholarly journals Analysis of Large-Strain Consolidation Behavior of Soil with High Water Content in Consideration of Self-Weight

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yupeng Cao ◽  
Jian Yang ◽  
Guizhong Xu ◽  
Jianwen Xu
Keyword(s):  
Pore Water ◽  
Void Ratio ◽  
Pore Water Pressure ◽  
Large Strain ◽  
Water Pressure ◽  
Average Degree ◽  
High Water Content ◽  
Excess Pore Water Pressure ◽  
Degree Of Consolidation ◽  
Excess Pore

Based on the axisymmetric large-strain consolidation (ALSC) model with the void ratio as the variable under equal strain condition, difference schemes of model’s equation, initial condition, and boundary condition were given. Taking phosphatic clay in Florida as a research object, the consolidation behaviors of soil with high water content by axisymmetric large-strain theory and one-dimensional large-strain theory were analyzed. The effect of different kinds of consolidation theories and self-weight stress on an average degree of consolidation was evaluated. The development of the void ratio and excess pore water pressure along the soil layer was clarified. The results show that the theoretical value of Terzaghi’s consolidation degree is always less than that of ALSC (Us, the average degree of consolidation defined by strain)-vertical drainage in the consolidation process. Terzaghi’s solution overestimates the dissipation rate of excess pore water pressure during the earlier consolidation period but underestimates it during the later consolidation period. The degree of consolidation calculated by Hansbo develops faster than ALSC (Up, the average degree of consolidation defined by stress)-radial drainage, but slower than ALSC (Us)-radial drainage. In the ALSC model, Us is always been faster than Up. The effect of self-weight on the consolidation degree of axisymmetric large-strain consolidation theory is relatively small (maximum error is less than 16%), while it can accelerate the consolidation rate of soil in one-dimensional large-strain consolidation theory largely. When only the vertical drainage occurs, the consolidation rate in the middle of the soil is obviously lagging the upper and lower parts, while the radial drainage can reduce the void ratio and the excess pore water pressure along the soil layer uniformly and more rapidly.

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