Field performance of the port of Sepetiba test fills

1995 ◽  
Vol 32 (1) ◽  
pp. 106-121 ◽  
Author(s):  
Vinod K. Garga ◽  
Luciano V. Medeiros
Keyword(s):  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Field Performance ◽  
Stone Columns ◽  
Field Investigations ◽  
Large Program ◽  
Soil Deposits ◽  
Load Tests ◽  
The Cost

The design of the industrial port of Sepetiba, 50 km south of Rio de Janeiro, Brazil, required a detailed evaluation of the underlying soft soil deposits. Initially, on the basis of laboratory tests, it was proposed to remove approximately 3.7 × 106 m3 of the very soft deposits in the stockpile area by dredging and substitute with hydraulic sand fill. Subsequently, in view of the cost of such a measure, a large program of field investigations was initiated to study the in situ characteristics of the soft clay to evaluate whether replacement of this material and (or) ground improvement was necessary. As part of this investigation, two large identically instrumented test fills (test fills B and D), each 65 m2 in plan and 5 m high, with 3:1 slopes were constructed. Test fill B was constructed over natural ground, whereas the subsoil beneath test fill D was treated with stone columns. The instrumentation for each test fill consisted of piezometers, deep settlement plates, surface settlement plates, and inclinometers. This paper provides a description of the field investigations, observations on installation of stone columns, analysis of instrumentation, a comparison of the behaviour of the two test fills, and a discussion on load tests on individual stone columns. Key words : case history, embankment, ground improvement, instrumentation, soft clay, stone columns.

scholarly journals Optimisation of Cost in Ground Improvement for Upcoming Navi Mumbai International Airport

2021 ◽  
Vol 10 (6) ◽  
pp. 174-181
Author(s):  
M. P. Suryawanshi ◽  
◽  
Raju Narwade ◽  
Karthik Nagrajan ◽  
◽  
...  
Keyword(s):  
Ground Improvement ◽  
Soft Clay ◽  
Cost Optimization ◽  
Stone Columns ◽  
Development Projects ◽  
Coastal Regions ◽  
International Airport ◽  
The Past ◽  
Appropriate Treatment ◽  
The Cost

This study aimed to optimise the cost of ground improvement by considering the residual settlement in marshy lands for development of new International airport by applying the appropriate treatment to overcome the issues that meets cost and time. Globally the increasing demands of trading and servicing activities require the development of an International airport in major cities. The Mumbai is one of the biggest commercial destinations of our country also necessitates the development of another airport besides the existing airport in the region. From the past few decades, researches and studies show various ways of ground improvements for the airport area in coastal regions. This study shows the cost optimization of ground improvement work by adopting the end on dumping of locally available blasted rocks instead of ground improvement techniques. This study works on principle that stone is puncturing to the very soft to soft clay and at the same time clay are getting displaced thus, effective thickness of clay is getting reduced. The objectives of this study are to optimize the cost of ground improvement and reduce the residual settlement of airport land in coastal regions. Adopting of end on dumping methods is appropriate in view of cost and feasibility of site than the ground improvement techniques. The cost of end on dumping is Thirty-six percent less than the stone columns technique. It can be concluded that for future ground development projects filling of stones by the end of the dumping method can be considered as the appropriate solution concerning time and cost.

Uplift and Settlement Prediction Model of Marine Clay Soil e Integrated with Polyurethane Foam

2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Clay Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Effective Thickness ◽  
Marine Clay ◽  
Uplift Pressure ◽  
Pu Foam ◽  
Improvement Method

AbstractPolyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.

Field Performance of a Deep Multi-Strutted Excavation in Hangzhou Soft Clays

2011 ◽  
Vol 243-249 ◽  
pp. 2324-2327
Author(s):  
Hong Wei Ying ◽  
Yong Wen Yang ◽  
Xin Yu Xie
Keyword(s):  
Large Scale ◽  
Soft Soil ◽  
Soft Clay ◽  
Ground Surface ◽  
Field Performance ◽  
Soft Clays ◽  
Soil Clays ◽  
History Of ◽  
Creep Deformations ◽  
Surface Settlements

A case history of a deep multi-strutted soft clay excavation in Hangzhou is presented in this paper. What makes it particular interest is its three characteristics: large scale, deep excavation and very soft clays. The excavated area was about 99750 square meters. The depth of excavation was 12.85 m. 4 m below the ground surface located about 24 m very soft soil clays. Wall deflections and ground settlements were measured and compared with similar case histories worldwide. It was shown that the maximum horizontal deformations of the excavation was very large which this excavation reached to 220 mm. “Creep” deformations occurred apparently during the curing of the bottom slab of the basement. The distributions of the surface settlements seemed to be parabolic, and the settlement influence zone could reach to a distance of more than 2H, whereHis the final excavation depth. The ratio between the maximum ground settlement and the maximum horizontal deformation of the wall is about 0.6.

scholarly journals A Review on the Behaviour of Combined Stone Columns and Pile Foundations in Soft Soils when Placed under Rigid Raft Foundation

2021 ◽  
Vol 16 ◽  
pp. 1-8
Author(s):  
Danish Ahmed ◽  
Siti Noor Linda Bt Taib ◽  
Tahar Ayadat ◽  
Alsidqi Hasan
Keyword(s):  
Ground Improvement ◽  
Soft Soil ◽  
Research Work ◽  
Stone Columns ◽  
Attractive Alternative ◽  
Soft Soils ◽  
Ongoing Research ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Raft Foundations

In the last few decades, it has been observed that raft foundations are very commonly used as a foundation solution for moderate to high rise structures either by resting on stone columns or on piles in soft soils. It is believed that, combining stone columns and piles in one foundation system is the more suitable foundation for medium rise structures. The combined foundation system provides a superior and more economical alternative to pile, and a more attractive alternative to stone columns in respect to ground improvement. This paper presents the review of existing studies reported in the literature in the last two decades about the behaviour of stone columns under raft foundations and piled raft foundation in soft soil, notably the failure mechanism and the bearing capacity. Also, a limited work from the literature concerning the performance of combined (pile/stone columns) foundation system in soft soil is comprised. Furthermore, very extensive ongoing research work regarding the investigation and study on the performance of combined (pile/stone columns) foundation system in soft soils is discussed. The main goals and methodology to study the performance of the combined (pile/stone columns) foundation systems in soft soil are also addressed.

scholarly journals Geosynthetic Encased Columns Supporting Rail Infrastructure – Perspectives on Research and Case Studies

2020 ◽  
Author(s):  
Erol Guler ◽  
Cihan Cengiz ◽  
Oliver Detert
Keyword(s):  
Case Studies ◽  
Ground Improvement ◽  
Soft Soil ◽  
Academic Research ◽  
Major Effect ◽  
Economic Benefits ◽  
Shaking Table ◽  
Stone Columns ◽  
Soil Conditions ◽  
Rail Network

Significant investments are being made towards enhancing the reach of the railway infrastructure due to the vast economic benefits it brings. An inevitable consequence of the expansion of the rail network is the soft soil conditions encountered in the alignment. Geosynthetic encased columns (GEC) is a proven ground improvement technology which can be adapted as soil remediation technique for such conditions. In this paper, first an introduction to the concept of GECs will be given. Then the recent advances in the academic research on the GECs will be elaborated. As it is known, earthquakes are one of the most devastating disasters and certainly also have a major effect on transportation infrastructure. In this paper results of shaking table tests to compare ordinary stone columns and GECs behavior under earthquake loading conditions will also be presented. The brief recap of the state of the art on the geosynthetic encased columns including their earthquake behavior will be followed by case studies on three major projects where the site conditions and project requirements will be discussed. The significant benefits of geosynthetic encased columns in relation to project requirements will also be elaborated.

scholarly journals Seismic Analysis of Floating Stone Columns in Soft Clayey Soil

2021 ◽  
Vol 318 ◽  
pp. 01008
Author(s):  
Mahdi O. Karkush ◽  
Amer G. Jihad ◽  
Karrar A. Jawad ◽  
Mustafa S. Ali ◽  
Bilal J. Noman
Keyword(s):  
Clayey Soil ◽  
Seismic Analysis ◽  
Lateral Displacement ◽  
Soft Soil ◽  
Soft Clay ◽  
Surface Displacement ◽  
Stone Columns ◽  
Stone Column ◽  
Plastic Behavior ◽  
Ground Acceleration

The response of floating stone columns of different lengths to diameter ratio (L/D = 0, 2, 4, 6, 8, and 10) ratios exposed to earthquake excitations is well modeled in this paper. Such stone column behavior is essential in the case of lateral displacement under an earthquake through the soft clay soil. ABAQUS software was used to simulate the behavior of stone columns in soft clayey soil using an axisymmetric finite element model. The behavior of stone column material has been modeled with a Drucker-Prager model. The soft soil material was modeled by the Mohr-Coulomb failure criterion assuming an elastic-perfectly plastic behavior. The floating stone columns were subjected to the El Centro earthquake, which had a magnitude of 7.1 and a peak ground acceleration of 3.50 m/s2. The surface displacement, velocity, and acceleration in soft clayey enhanced by floating stone columns are also smaller than in natural soft clay. The findings of this research revealed that under the influence of earthquake waves, lateral displacement varies with stone columns of various lengths.

scholarly journals Settlement Behaviour of Soft Soil Reinforced with Geogrid Encased Stone Column under Sustained Loading

2019 ◽  
Vol 9 (2) ◽  
pp. 1307-1311
Keyword(s):  
Ground Improvement ◽  
Soft Soil ◽  
Stone Columns ◽  
Stone Column ◽  
Replacement Ratio ◽  
Sustained Loading ◽  
Settlement Behavior ◽  
Column Material ◽  
Area Replacement Ratio ◽  
Different Diameters

The use of stone columns in improving the bearing capacity of soft soil is well researched, but the understanding of settlement requires further studies. This paper presents the results of a series of laboratory tests carried out to study the settlement behavior of soft soil bed reinforced with ordinary stone column (OSC) and Geogrid encased stone columns (GESC). Kaolin was used as the soft soil and stones of size from 2.5 to 10 mm were used as column material. The stone columns of four different diameters were installed, by the method of replacement, into the soil having undrained shear strength of 22.5 kPa. The OSC and GESC test beds were subjected to pressure of 250 and 300 kPa. Each pressure was sustained for 24 hours and the settlement of the composite soil with time was noted. It is found that Geogrid encased stone columns have small settlement than the corresponding ordinary stone columns. The SRR (settlement reduction ratio) being a measure of ground improvement, is found increasing with the area replacement ratio. Further, at a particular sustained pressure SRR is found more for GESC than the corresponding value for OSC.

scholarly journals The Impact of Using Different Types of Soft Soils Treated by Stone Columns on Creep Behavior

2022 ◽  
Vol 961 (1) ◽  
pp. 012052
Author(s):  
Sura Tawfeeq Al-Auqbi ◽  
Nahla M. Salim ◽  
Mahmood R. Mahmood
Keyword(s):  
Soft Soil ◽  
Horizontal Displacement ◽  
Cohesive Soil ◽  
Stone Columns ◽  
Stone Column ◽  
Geometric Conditions ◽  
Improvement Factor ◽  
Soil Deposits ◽  
Different Types ◽  
The Impact

Abstract The stone column technique is an effective method to increase the strength of soft cohesive soil, which results in a reduction in foundation settlement and an increase in bearing capacity. The topic of restraining creep settlement through the use of stone columns techniques has gained increasing attention and consideration; because stone columns are widely used to treat soft soil deposits, caution should be applied in estimating creep settlement. We discovered a reversible relation between shear parameters and the creep settlement in floating stone columns; while, in case of end-bearing stone columns shows a direct positive relation between shear parameters and the creep settlement, and the creep settlement began at the primary settlement. The shear parameters affected the improvement factor (n) of creep settlement in both floating and end-bearing stone columns. The standard creep coefficient’s n values in floating and end-bearing conditions were more significant than the low creep coefficient’s n values in forwarded geometric conditions. The stress in both floating and end-bearing stone columns was increasing and uniformly distributed along the length of the floating stone column and in the case of end-bearing stone column was limited to the stiffness layer; the maximum vertical stress was in the central point of the embankment. The embankment’s maximum horizontal displacement occurred on the edge.

scholarly journals Comparison between unit cell and plane strain models of stone column ground improvement

2018 ◽  
Vol 7 (2) ◽  
pp. 263
Author(s):  
Maryam Gaber ◽  
Anuar Kasa ◽  
Norinah Abdul Rahman ◽  
Jamal Alsharef
Keyword(s):  
Stress Concentration ◽  
Plane Strain ◽  
Clayey Soil ◽  
Cell Model ◽  
Ground Improvement ◽  
Soft Soil ◽  
Unit Cell ◽  
Stone Columns ◽  
Stone Column ◽  
The Impact

This article presents a comparative study of the behaviour of clayey soil reinforcements using stone column ground improvement by means of numerical analyses. Two-dimensional finite element analyses with commercially available software, PLAXIS, were performed on end-bearing stone columns using 15-noded triangular elements to investigate the impact of the modelling type on the stress concentration ratio and failure mechanism of an improved foundation system. Consolidation analyses were conducted throughout the study using Mohr-Coulomb’s criterion. The computed values of the stress concentration ratios were compared for different key parameters, including the diameters of stone columns, c/c spacing of columns, friction angle of stone column material, and undrained cohesion of soft soil. The major conclusions of this study were that the stone column in the unit cell model shared between 2.5 to 3.14 times more loads than the surrounding soil, whilst in the plane strain model it shared between 1.7 to 2.9 times more loads. The use of plane strain approach to model the stone column gave a more comprehensive representation of the stress distribution and load transfer between the soil and columns, in addition to being a better method than the unit cell concept to evaluate the failure mode in this system.

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