A Deep Excavation and a Raft Foundation in Soft Clay

1972 ◽  
Vol 9 (3) ◽  
pp. 237-248
Author(s):  
A. Insley
Keyword(s):  
Case History ◽  
Soft Clay ◽  
Deep Excavation ◽  
Safety Factors ◽  
Marine Clay ◽  
Foundation Design ◽  
Foundation Soil ◽  
Actual Performance ◽  
Raft Foundation ◽  
Building Foundation

This is a case history describing a deep braced excavation in which a fully compensated raft foundation was constructed. The foundation soil is the Victoria marine clay, which is a soft normally consolidated deposit 70–100 ft (21–30 m) thick at this site. Observations were made on the deflections of the bracing and the heave of the excavation and were considered a necessary part of the design. Observations have also been kept on the settlement of the building foundation for over [Formula: see text] years. The calculated safety factors used in bracing design and foundation design are compared against the actual performance.

scholarly journals Design and Improvement of foundation soil for high-rise construction

2018 ◽  
Vol 170 ◽  
pp. 03001 ◽  
Author(s):  
Kwa Sally Fahmi ◽  
Mohammed Y. Fattah ◽  
Andrey Pustovgar
Keyword(s):  
Fem Analysis ◽  
Stone Columns ◽  
3D Fem ◽  
Foundation Design ◽  
Foundation Soil ◽  
Total Load ◽  
High Rise ◽  
Raft Foundation ◽  
Dimensional Finite Element ◽  
Current Design

The assessments were made in the current practice based on the design foundation of high-rise buildings in Moscow to find a method for improving the soil foundation. Many references showed that the current design was controlled by structural engineers. They commonly used the old methods of analysis, the first part was carried out for the design of the structure and architecture of high-rise building, the second part of the study was to explore the benefit of adopting the application of stone columns raft foundation design concept. A comparative study was made between the results of the 3-dimensional finite element (3D FEM) analysis in SCAD software. The results showed that the plate foundation of the building does not satisfy to carry the total load without some meaning of improvement. The 3D FEM by PLAXIS 3D showed that the used stone columns decreased the settlement because about 70-80% of the total building loads were carried by columns when the raft was placed in the stiff clay layer. The number of columns in the raft foundation can be significantly reduced, particularly if the soil had strong characteristics. The raft foundation settlement can be significantly reduced, particularly if the soil had strong characteristics.

Deformation Characteristics of Determination of Mechanical Properties of Experimental Teaching of Cohesive Soil under Constrained Conditions

2014 ◽  
Vol 543-547 ◽  
pp. 4018-4021
Author(s):  
Yu Ling Zhao
Keyword(s):  
Cohesive Soil ◽  
Geological Structure ◽  
Theory And Practice ◽  
Quantitative Relation ◽  
Foundation Engineering ◽  
Soil Consolidation ◽  
Foundation Design ◽  
Foundation Soil ◽  
Experimental Teaching ◽  
Building Foundation

Under the various load combination of buildings, the deformation of foundation soil. The size of the deformation directly affects the safety of the buildings. Factors that affect the deformation is mainly the geological structure, such as moisture content, density, soil after being compressed volume smaller feature is the compressibility of soil. Geotechnical engineering is a direction of the development of the civil engineering specialty, test provide necessary parameters for building foundation engineering, geotechnical laboratory for cohesive soil consolidation experiment teaching, make students grasp to determine the quantitative relation between the deformation and load, compression curve and rebound curve drawing, it provide necessary theoretical basis for geological prospecting work, provide necessary parameters for building foundation design, closely integrated theory and practice..

Issues on Design of Piled Raft Foundation

2018 ◽  
Vol 14 (1) ◽  
pp. 6057-6061 ◽  
Author(s):  
Padmanaban M S ◽  
J Sreerambabu
Keyword(s):  
Contact Area ◽  
Concrete Slab ◽  
Design Procedure ◽  
Bending Moment ◽  
Foundation Design ◽  
Detailed Review ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Influencing Parameters

A piled raft foundation consists of a thick concrete slab reinforced with steel which covers the entire contact area of the structure, in which the raft is supported by a group of piles or a number of individual piles. Bending moment on raft, differential and average settlement, pile and raft geometries are the influencing parameters of the piled raft foundation system. In this paper, a detailed review has been carried out on the issues on the raft foundation design. Also, the existing design procedure was explained.

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.

Effect of Lime on Compaction, Strength and Consolidation Characteristics of Pontian Marine Clay

2015 ◽  
Vol 72 (3) ◽  
Author(s):  
Siaw Yah Chong ◽  
Khairul Anuar Kassim
Keyword(s):  
Construction Material ◽  
Soft Clay ◽  
Engineering Properties ◽  
Dry Density ◽  
Marine Clay ◽  
Maximum Dry Density ◽  
Stabilization Phase ◽  
Compaction Curve ◽  
Stabilized Soil

Marine clay is a problematic construction material, which is often encountered in Malaysian coastal area. Previous researchers showed that lime stabilization effectively enhanced the engineering properties of clay. For soft clay, both strength and consolidation characteristics are equally important to be fully understood for design purpose. This paper presented the effect of lime on compaction, strength and consolidation characteristics of Pontian marine clay. Compaction, unconfined compression, direct shear, Oedometer and falling head permeability tests were conducted on unstabilized and lime stabilized samples at various ages. Specimens were prepared by compaction method based on 95 percent maximum dry density at the wetter side of compaction curve. It was found that lime successfully increased the strength, stiffness and workability of Pontian marine clay; however, the permeability was reduced. Unconfined compressive strength of stabilized soil was increased by 49 percent at age of 56 days whereas compressibility and permeability was reduced by 48 and 67 percent, respectively. From laboratory tests, phenomenon of inconsistency in engineering characteristics was observed for lime stabilized samples below age of 28 days. This strongly proved that lime stabilized soil underwent modification phase before stabilization phase which provided the long term improvement.

Soil-Structure Interaction in Buildings from Earthquake Records

1990 ◽  
Vol 6 (4) ◽  
pp. 641-655 ◽  
Author(s):  
Gregory L. Fenves ◽  
Giorgio Serino
Keyword(s):  
Soil Structure ◽  
Dynamic Properties ◽  
Strong Motion ◽  
Longitudinal Direction ◽  
Soil Structure Interaction ◽  
Base Shear ◽  
Foundation Soil ◽  
Soil System ◽  
Structure Interaction ◽  
Building Foundation

An evaluation of the response of a fourteen story reinforced concrete building to the 1 October 1987 Whittier earthquake and 4 October 1987 aftershock shows significant effects of soil-structure interaction. A mathematical model of the building-foundation-soil system provides response quantities not directly available from the records. The model is calibrated using the dynamic properties of the building as determined from the processed strong motion records. Soil-structure interaction reduces the base shear force in the longitudinal direction of the building compared with the typical assumption in which interaction is neglected. The reduction in base shear for this building and earthquake is approximately represented by proposed building code provisions for soil-structure interaction.

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