scholarly journals Numerical Modeling of Shallow Foundation Behavior Using Soft Soil Model

2022 ◽  
Vol 961 (1) ◽  
pp. 012057
Author(s):  
BA Al-Dawoodi ◽  
MQ Waheed ◽  
FH Rahil
Keyword(s):  
Bearing Capacity ◽  
Clayey Soil ◽  
Soft Soil ◽  
Shallow Foundation ◽  
Clayey Soils ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Element Analysis ◽  
Soil Model ◽  
Different Types

Abstract This study discusses the results of simulation a finite element analysis of the load-settlement curve using soft soil model of shallow foundation subjected to axial load rested on three different types of clayey soils, it was considered different shear strength parameters (C=16, C=25, and C=70). It was concluded for clayey soil of C=16, there was a match to the experimental load – settlement curve using the soft soil model. It was also observed increase in the foundation width led to an increase in bearing capacity, however, bearing capacity increased by around (79 %) for an increase in footing width of (6.25), so it was about (144%) for (12.5).

scholarly journals Effect of gypsum content on unsaturated engineering properties of clayey soil

2020 ◽  
Vol 9 (1) ◽  
pp. 84
Author(s):  
Mohammed N J Alzaidy
Keyword(s):  
Shear Strength ◽  
Clayey Soil ◽  
Engineering Properties ◽  
Water Retention Curve ◽  
Shear Strength Parameters ◽  
Swelling Potential ◽  
Soil Water Retention Curve ◽  
Strength Parameters ◽  
Gypsum Content ◽  
Vapour Diffusion

Many of gypsum soils have existed in arid and semi-arid lands. It is considered one of the most problematic soils because of its complicated and unpredicted behavior when exposure to moisture. Extensive researches have been conducted in Iraq to observe the behavior of such soil and to suggest safety restrictions for the collapse and set practical precautions for the structures. This study investigated the effect of gypsum content on some unsaturated engineering properties of a clayey soil. Three different proportions of gypsum (0%, 5% and 20% by weight of the parent soil) were added and tested. The samples have been subjected to swelling potential test, soil water retention curve (SWRC), vapour diffusion and shear strength parameters. It is observed that gypsum content has a significant influence on SWRC, whereas, soil that has high gypsum content made SWRC with higher variables represented by air entry values and residual state. On the other hand, an increase in gypsum content led to a reduction of swelling potential and shear strength parameters. The results of vapour diffusion indicate that gypsum content could modify the microstructure in an unsaturated state and reduce the vapour diffusion through the soil.  

Analytical Study of Load-Settlement Behavior of Soil Treated with Stone Columns have Different Sectional Shape

2020 ◽  
Vol 857 ◽  
pp. 319-327
Author(s):  
Moataz A. Al-Obaydi ◽  
Zeena A. Al-Kazzaz
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Engineering Properties ◽  
Stone Columns ◽  
Equivalent Diameter ◽  
Element Analysis ◽  
Cross Sectional ◽  
Treated Soil ◽  
Almost All ◽  
Sectional Shape

Stone columns have been used widely to improve the engineering properties of the weak soil. Most of the previous works considered a circular section for the stone columns. In the present study, finite element analysis has been carried out to investigate the effect of stone columns shape and length on the settlement and bearing capacity of soft soil. Accordingly, three types of cross sectional shape for stone columns have been selected which they are circular, rectangular, and square sections with equivalent area. Various length of columns are adopted with diameter of 0.75m that achieved length to diameter or equivalent diameter ratios (L/d=2, 4, 6, 8, and 10) of columns spacing (S/d=3). The results show that the stone columns has tangible effects on the settlement of the soil while has minor effects on the bearing capacity. The settlement of the treated soil with stone columns have L/d=2, reduces by 18.0, 17.3, and 19.3% for circular, rectangular , and square sections respectively. With increasing length of the columns to L/d=10, further reductions in the settlement obtained of (27.1, 28.1, and 27.0%). Bearing capacity of the soil increased slightly with length of the stone columns. Almost all cross sectional shapes of the columns give bearing capacity about same. The increased in the bearing capacity of the treated soil with stone columns have L/d=2, not exceeded 10% for all sectional types. The average increments in bearing capacity when L/d=10 are 12 and 15% at settlement 50 and 100mm respectively. Insignificant changes in bearing capacity upon increasing length of columns from L/d=2 to 10 of maximum 5%. The plastic zone recedes with the increasing length of the stone columns. Finally, from the results obtained, it can be concluded that the stone columns shape has negligible effects on the settlement and bearing capacity of the soil.

Influence of Foundation Type on Seismic Performance of Buildings Considering Soil–Structure Interaction

2016 ◽  
Vol 16 (08) ◽  
pp. 1550043 ◽  
Author(s):  
Aslan S. Hokmabadi ◽  
Behzad Fatahi
Keyword(s):  
Seismic Response ◽  
Pile Foundation ◽  
Soil Structure ◽  
Soft Soil ◽  
Shallow Foundation ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Raft Foundation ◽  
Different Types

In selecting the type of foundation best suited for mid-rise buildings in high risk seismic zones, design engineers may consider that a shallow foundation, a pile foundation, or a pile-raft foundation can best carry the static and dynamic loads. However, different types of foundations behave differently during earthquakes, depending on the soil–structure interaction (SSI) where the properties of the in situ soil and type of foundation change the dynamic characteristics (natural frequency and damping) of the soil–foundation–structure system. In order to investigate the different characteristics of SSI and its influence on the seismic response of building frames, a 3D numerical model of a 15-storey full-scale (prototype) structure was simulated with four different types of foundations: (i) A fixed-based structure that excludes the SSI, (ii) a structure supported by a shallow foundation, (iii) a structure supported by a pile-raft foundation in soft soil and (iv) a structure supported by a floating (frictional) pile foundation in soft soil. Finite difference analyzes with FLAC3D were then conducted using real earthquake records that incorporated material (soil and superstructure) and geometric (uplifting, gapping and [Formula: see text] effects) nonlinearities. The 3D numerical modeling procedure had previously been verified against experimental shaking table tests conducted by the authors. The results are then presented and compared in terms of soil amplification, shear force distribution and rocking of the superstructure, including its lateral deformation and drift. The results showed that the type of foundation is a major contributor to the seismic response of buildings with SSI and should therefore be given careful consideration in order to ensure a safe and cost effective design.

Bearing capacity of soft soil model treated with end-bearing bottom ash columns

2018 ◽  
Vol 77 (3) ◽  
Author(s):  
Razieh Moradi ◽  
Aminaton Marto ◽  
Ahmad Safuan A. Rashid ◽  
Mohammad Moeen Moradi ◽  
Abideen Adekunle Ganiyu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Bottom Ash ◽  
Soil Model

scholarly journals Prediction the Behavior of Piles in Clayey Soils

2018 ◽  
Vol 7 (4.20) ◽  
pp. 157
Author(s):  
Hanan Adnan Hasan
Keyword(s):  
Ultimate Load ◽  
Lateral Displacement ◽  
Soft Soil ◽  
Reduction Factor ◽  
Interface Element ◽  
Clayey Soils ◽  
Ultimate Capacity ◽  
Element Analysis ◽  
Stiff Clays ◽  
Stiff Clay

This research includes a non- linear finite element analysis of axisymmetric soil-pile system. The analysis included piles of different length and diameter. The interface element was used as a thin layer separating the pile from surrounding soil. The load settlement curves for piles installed in soft to medium and stiff clays were obtained. Two consideration were studied; the ultimate capacity of pile and the settlement reduction factor. The results show that increase in the length and diameter of pile leads to increase in the ultimate load in range (35- 60%) and in the range (33- 35) % respectively. The distribution of lateral displacement along the depth of the pile gave the same trend in both soft to medium and stiff clay while the settlement reduction factor in soft soil is greater than for the stiff clay.   

scholarly journals A Study on the Utilization of Clayey Soil as Embankment Material through Model Bearing Capacity Tests

2020 ◽  
Vol 10 (7) ◽  
pp. 2315
Author(s):  
Myoung-Soo Won ◽  
Christine P. Langcuyan ◽  
Yu-Cong Gao
Keyword(s):  
Moisture Content ◽  
Bearing Capacity ◽  
Clayey Soil ◽  
Western Coast ◽  
Silty Clay ◽  
Clayey Soils ◽  
Test Results ◽  
Basic Study ◽  
Dense Sand ◽  
Internal Development

The Saemangeum seawall, located on the western coast of Korea, is 33.8 km long and is known as the longest embankment in the world. The Saemangeum project is underway for road, railway, and port constructions for internal development. In the Saemangeum area, suitable granular soil for embankment material is difficult to obtain. However, silty clay is widely distributed. In this study, a series of model-bearing capacity tests were conducted as a basic study for using clayey soils as embankment materials. The model bearing capacity tests were carried out using a standard metal mold and a customized metal box. The test results showed that clayey soil, with normal moisture content (NMC), exhibited a large deformation and low bearing capacity. However, when the clay was well-compacted, with optimum moisture content (OMC), it exhibited a higher bearing capacity than dense sand. In addition, when crushed gravel and composite geotextiles were placed in the clayey soil with NMC, the bearing capacity was higher than that of dense sand. From the viewpoint of the bearing capacity, it is considered that clayey soil can be used as an embankment material when clay, crushed gravel, and composite geotextiles are properly combined.

scholarly journals Stabilization of Soft Soil with Cement and Palm Kernel Shell Ash Admixture

2019 ◽  
Vol 280 ◽  
pp. 04011 ◽  
Author(s):  
Yulian Firmana Arifin ◽  
Gazali Rahman
Keyword(s):  
Soft Soil ◽  
Soft Clay ◽  
Palm Kernel ◽  
Curing Time ◽  
Soil Series ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Palm Kernel Shell ◽  
Soil Cement ◽  
Undrained Strength

This paper focuses the results of the improvement in shear strength parameters and CBR of soft clay when stabilized with cement and cement-Palm Kernel Shell Ash (PKSA). Different combinations of soil- cement and soil-cement-PKSA mixtures are prepared with the addition of cement and PKSA in the range of 2-10% by weight of soil. Series of tests including compaction, UCT, and CBR tests were performed. The influence of curing time is also studied on CBR and undrained strength property of various sample combinations. Results indicate that the addition of PKSA to the soil-cement mixtures increases the CBR. The percentage of optimum PKSA content in the mix for soil with 10% cement is 2%. The effect of time on clay, cement, and PKSA mixture is significant, i.e. an average of 0.5% per day.

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