scholarly journals Settlement Behavior Evaluation of Soft-Clay Layer Reinforced with Sand Piles

2022 ◽  
Vol 07 (01) ◽  
Author(s):  
Serpil Erden ◽  
Keyword(s):  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Single Pile ◽  
Soil Model ◽  
Settlement Behavior ◽  
Water Saturated ◽  
Saturated Soft Clay ◽  
Sand Piles ◽  
Hardening Soil Model

In this study, the performances of the sand piles in Istanbul's Bağcılar and Zeytinburnu districts has been analyzed using Finite Element Method (FEM). Single and group (triple) piles with various length/diameter ratios (L/D) were placed in the water-saturated soft clay soil. Sand piles were modeled in various L/D ratios (10, 5.71, and 8.57). The distance between the piles was chosen as 2 meters and the group effect was also investigated. A uniformly distributed load of 162 kN/m2 is placed on the ground. In addition, the soil was modeled with the Soft-Soil soil model, the hardening soil model for the infill part, and the sand piles with the Mohr-Coulomb soil model. According to the results , the settlement of the soil decreases by 52.8% for a single pile with an L/D ratio of 8.57. However, the best L/D ratio for triple piles was found to be 5.71. In this case, the settlement decreases by 52.8% compared to the pileless situation. Finally it was concluded that the model with the L/D ratio of 8.57 reduced settlement in the best and the most efficient way.

scholarly journals Analisis Vacuum Consolidation pada Perbaikan Tanah Lempung Lunak dengan Model Axisymmetric (Hal. 68-79)

2018 ◽  
Vol 4 (1) ◽  
pp. 68
Author(s):  
Nadya Utami Rivanga ◽  
Indra Noer Hamdhan
Keyword(s):  
Shear Strength ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Vacuum Consolidation ◽  
Final Project ◽  
Vertical Drain ◽  
Soil Model ◽  
Low Shear

ABSTRAKTanah lempung lunak merupakan jenis tanah yang memiliki kuat geser yang kecil, koefisien permeabilitas yang kecil, kompresibilitas yang besar, dan mempunyai daya dukung rendah. Kondisi tersebut menyebabkan tanah lempung lunak menjadi tantangan pada kontruksi yang akan di bangun diatasnya, sehingga diperlukan perbaikan tanah. Salah satu perbaikan tanah untuk tanah lempung lunak yang banyak dijumpai yaitu vertical drain dan preloading. Pada tugas akhir ini metode tersebut akan dikombinasikan dengan vacuum consolidation. Tegangan vakum yang digunakan pada kasus ini sebesar 50 dan 80 kPa. Analisis yang dilakukan dengan menggunakan program PLAXIS 2D dengan model Axisymmetric. Analisis dilakukan dengan memvariasikan tiga dari sekian banyak soil model yaitu Mohr Coulomb, Hardening Soil, dan Soft Soil. Berdasarkan hasil dari penelitian nilai penurunan, tegangan pori, dan waktu konsolidasi yang dihasilkan berbeda tetapi hasil penurunan soil model dengan Hardening Soil dan Soft Soil tidak terlalu berdeda secara signifikan.Kata Kunci: tanah lempung lunak, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D  ABSTRACTSoft clay is a type of soil that has low shear strength,  high compressibility,  low coeffiecient of permeability and low bearing capacity. The condition caused soft clay soil to be a challenge on the construction that will be built on it, so that it needed soil improvement. The soil improvement for soft clay that often found is vertical drain and preloading. In this final project that method will be combined with vacuum consolidation. The vacuum pressure used in this case amount from 50 and 80 kPa. The analysis was performed using PLAXIS 2D program with Axisymmetric model. The analysis was done by varying the three of soil models Mohr Coulomb, Hardening Soil, and Soft Soil. Based on the settlement of the research, settlement value, pore pressure, and time of consolidation are different but the result of soil models of Hardening Soil and Soft Soil is not significantly differentiated.Keywords: soft clay, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D

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.

scholarly journals Design Charts for Axially Loaded Single Pile Action

2019 ◽  
Vol 5 (4) ◽  
pp. 922-939 ◽  
Author(s):  
Anis Abdul Khuder Mohamad Ali ◽  
Jaffar Ahemd Kadim ◽  
Ali Hashim Mohamad
Keyword(s):  
Clay Soil ◽  
Skin Resistance ◽  
Soft Clay ◽  
Single Layer ◽  
Load Test ◽  
Engineering Properties ◽  
Single Pile ◽  
Dense Sand ◽  
Design Charts ◽  
Pile Length

The objective of this article is to generating the design charts deals with the axially ultimate capacity of single pile action by relating the soil and pile engineering properties with the pile capacity components. The soil and are connected together by the interface finite element along pile side an on its remote end.  The analysis was carried out using ABAQUS software to find the nonlinear solution of the problem. Both pile and soil were modeled with three-dimensional brick elements. The software program is verified against field load-test measurements to verify its efficiency accuracy. The concrete bored piles are used with different lengths and pile diameter is taken equals to 0.6 m. The piles were installed into a single layer of sand soil with angles of internal friction (20° t0 40°) and into a single layer of clay soil with Cohesion (24 to 96) kPa.  The getting results showed that for all cases study the total compression resistance is increased as pile length increased for the same property of soil, also illustrious that the total resistance of same pile length and diameter increased as the soil strength increasing. In addition, the same results were obtained for the end bearing resistance, skin resistance and tension capacity. Design charts were constructed between different types of soil resistance ratio and the pile length/diameter ratio (L/D) for all cases of study. One of improvement found from these curves that it is cheaply using piles of larger diameter than increasing their lengths for dense sand and to increasing piles lengths for loose sand. Moreover, it is inexpensively using piles of larger length in soft clay soil than increasing their diameter and piles of larger diameter in firm and stiff clay soils than increasing their length.

scholarly journals Mohr-Coulomb and Hardening Soil Model Comparison of the Settlement of an Embankment Dam

2019 ◽  
Vol 9 (5) ◽  
pp. 4654-4658 ◽  
Author(s):  
A. H. Bhutto ◽  
S. Zardari ◽  
M. A. Zardari ◽  
G. S. Bhurgri ◽  
B. A. Memon ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Modulus Of Elasticity ◽  
Model Comparison ◽  
Embankment Dam ◽  
Sandy Gravel ◽  
Soil Model ◽  
Settlement Behavior ◽  
Coulomb Model ◽  
Clay Core ◽  
Hardening Soil Model

In this study, numerical analysis of an embankment dam was carried out to predict settlement behavior with the use of the Mohr-Coulomb Model (MCM) and of the Hardening Soil Model (HSM). The MCM was applied to all material zones of the dam and the HSM was used for four major material zones that occupied significant volume. The settlement response of the dam was similar for MCM and HSM for three material zones (clay core, sandy gravel and random fill), each having a modulus of elasticity (MOE) in the range of 25000 to 50000kPa. However, it was found that after the end of the construction, the MCM showed about 57% and 50% more settlement as compared to HSM when MOE of sandy siltstone varied from 70000 to 125000kPa respectively. The results regarding the dam settlement predicted with the HSM are in agreement with the findings in previous studies.

scholarly journals PENGARUH JARAK DAN POLA PREFABRICATED VERTICAL DRAIN (PVD) PADA PERBAIKAN TANAH LEMPUNG LUNAK = EFFECT OF DISTANCE AND PATTERN OF PREFABRICATED VERTICAL DRAIN FOR IMPROVEMENT OF SOFT CLAY SOIL

2016 ◽  
Vol 10 (1) ◽  
pp. 41-50
Author(s):  
Wimpie Agoeng Noegroho Aspara ◽  
Eka Nur Fitriani
Keyword(s):  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Analytical Calculation ◽  
Drainage System ◽  
Coefficient Of Consolidation ◽  
Consolidation Process ◽  
Foundation Soil ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain

AbstractIf a structure for reasons of technical, economic, social, or startegic is to be built on a soft ground, then there are usually two problems to be solved, namely the low geotechnical bearing capacity and large soil deformation with sometimes differential settlement. Pre-compression is a foundation soil compression process with the provision of temporary loading (preloading) before actually constructing a building. Pre-fabricated vertical drain is a synthetic drainage system installed vertically inside soft soil layers. Soil condition at the project activity is a relatively very soft clay soil with relatively high coefficient of consolidation resulting in very long period of consolidation process. Therefore, it is needed advance soil improvement by prealoding of pre-fabricated vertical drain. Spacings of installed PVD vary, those are 50 cm, 100 cm, 150 cm, and 200 cm with a pattern of triangles and rectangles. Based on the analytical calculation, it is resulted that optimum PVD distance to achieve 90% consolidation is 150 cm with a triangular pattern. The time of consolidation was achieved within four months. AbstrakKetika suatu struktur karena alasan-alasan teknis, ekonomi, sosial, atau strategis terpaksa didirikan di atas tanah lunak, maka biasanya ada dua masalah geoteknik yang harus dipecahkan yaitu daya dukung yang rendah dan penurunan serta beda penurunan yang besar. Prakompresi adalah suatu proses pemampatan tanah pondasi dengan jalan pemberian pembebanan sementara (prabeban/preloading) sebelum konstruksi yang sesungguhnya didirikan. Prefabricated vertical drain (PVD) adalah sistem drainase buatan yang dipasang vertikal di dalam lapisan tanah lunak. Kondisi tanah di lokasi kegiatan relatif sangat lunak dengan koefisien konsolidasi relatif sangat tinggi mengakibatkan proses konsolidasi berjalan relatif sangat lama. Untuk itu diperlukan perbaikan tanah terlebih dahulu dengan prealoading menggunakan PVD. Jarak spasi antar PVD yang dipasang bervaiasi yaitu 50 cm, 100 cm, 150 cm, dan 200 cm dengan pola konfigurasi segitiga dan segiempat. Berdasarkan hasil perhitungan secara analitis didapatkan jarak optimum PVD untuk mencapai konsolidasi 90% adalah 150 cm dengan pola segitiga dengan proses konsolidasi dicapai selama waktu penurunan 4 bulan.

scholarly journals STUDI SIFAT MEKANIS TANAH MERAH DENGAN PENGUJIAN TRIAKSIAL

2018 ◽  
Vol 7 (1) ◽  
pp. 29-34
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
Shear Strength ◽  
Soil Type ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Liquid Limit ◽  
Red Soil ◽  
Triaxial Tests ◽  
Limit Value ◽  
Triaxial Apparatus

Characteristics soft soil can cause instability and long-term degradation problems. This is because the soil has a low shear strength value and high compressibility. One type of soil belonging to the soft soil type is soft clay soil. Red soil belongs to the soft clay soil type. Therefore, the purpose of this research to determines the parameters of the shear strength of red soil in the area of Pakjo City Palembang, South Sumatra Province. The equipment had been used to obtain parameters of mechanical properties of red soil was using Triaxial apparatus. The results of the red soil properties index include: water content value (□ 27.70%, specific gravity value (Gs) 2.67, liquid limit value (LL) 66.00%, value of plastic limit of 25.13% and index value (IP) of 40.87% Classification of soil CH (USCS) and A-7-6 (AASHTO). The result of the Triaxial tests was the value of cohesion (c): 16.25-18, 15 kPa, and internal friction (□): 13.50-14.75⁰. The result of shear strength (□) : 17.68-24.02 kPa. The shear strength value of red soil indicates soil which includes soft soil (12.5-25 kPa).

scholarly journals Bearing Capacity of Floating Foundations Used PVC (Poly Vinyl Chloride) on Soft Soil With The Scale Model in the Field

2018 ◽  
Vol 7 (2.5) ◽  
pp. 84 ◽  
Author(s):  
Susy Srihandayani ◽  
Desi Putri ◽  
Nuning Kurniasih ◽  
Lusi Dwi Putri
Keyword(s):  
Theoretical Analysis ◽  
Bearing Capacity ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Maximum Load ◽  
Scale Model ◽  
Degradation Model ◽  
Poly Vinyl Chloride ◽  
Foundation Model

A soft clay soil has a low support energy, so it needs to be planned a foundation form that able to improve soil bearing capacity and estimate a maximum load that can be supported by that soil. Planning a float foundation is one of the solutions to overcome that problem. The behavior of burden degradation at float foundation which obtained from encumbering of axial introduced here. Proposed analysis based on classical theory and examination of foundation at the field. Float foundation models with different amount and dimension. At the field, a pipe which one of its ends closed tightly came into soft clay soil and then encumbered step by step. Giving an axial burden and degradation model area and noted. Boundary capacities in each foundation model estimated from the curve of load-displacement yielded of the test. From the result of theoretical analysis at a single float foundation got a proportionate result with the field result but after giving additional pile/pipe with larger one's cap got the theoretical result of bearing capacity bigger than the field result. The efficiency value of the comparison of bearing capacities theoretically that using five classic methods got more than 100%, and after giving additional pipe, the efficiency value near to 100%.  

UNCONFINED COMPRESSIVE STRENGTH AND MICROSTRUCTURE OF CLAY SOIL STABILISED WITH BIOMASS SILICA

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Fauziah Kasim ◽  
Aminaton Marto ◽  
Nur Amalina Abdul Rahman ◽  
Choy Soon Tan
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Engineering Properties ◽  
Test Results ◽  
Electron Microscopic ◽  
Treated Sample ◽  
Basic Characteristics

This study presents the Unconfined Compressive Strength (UCS) and microstructure of clay soil stabilized with locally made Biomass Silica (BS) in the form of SH-85. Since the construction of highway on soft soil raises many problems due to its low strength, understanding about the basic characteristics of soft clay and mixed with BS, play important role for improving the strength of the soft clay. The study carried out had the specific objectives to determine engineering properties of soft clay, to investigate the UCS of soft clay treated with BS and to analyze microstructure of the soft soil treated by BS with respect to various curing periods. In this study, 30 samples of clay soil were prepared under various curing periods (0, 7, 14 and 28 days) and mixed with BS at various percentages (5 %, 7 % and 9 %). The test results show that BS can increase the strength of the clay soil. The 9% BS treated sample for 7 days curing time achieved UCS of 710 kPa. This was approximately 6 times greater than that of untreated soil strength. The highest strength was 1216 kPa at 28 days curing for soil mixed with 9% BS. The images of Scanning Electron Microscopic show that the voids of the clay would filled by the new component resulted by the reaction of BS stabilizer with the natural clay samples. This led to a continuous soil fabric resulting with stronger and denser soil.

Research and Application on Laws of Consolidation Time Calculate in Saturated Soft Clay Soil by Using Vacuum-Surcharge Combined Preloading Method

2012 ◽  
Vol 594-597 ◽  
pp. 42-45
Author(s):  
Ping Bo Xu ◽  
Shu Qiang Lu ◽  
Ji Tao Zhang
Keyword(s):  
Clay Soil ◽  
Soft Clay ◽  
Soil Horizon ◽  
Complex Nature ◽  
Construction Technology ◽  
Soil Consolidation ◽  
Long Time ◽  
Dredger Fill ◽  
Saturated Soft Clay ◽  
Preloading Method

Vacuum-surcharge combined preloading method have been become the most commonly used method on the dredger fill and saturated soft clay soil consolidation beside the coast. The long time of consolidation is one of this method’s most characteristics, as we always think that 3 months is the academic time. In fact, we always can’t accomplish the consolidation of saturated soft clay soil by using vacuum-surcharge combined preloading method in 3 months because of the complex nature of the soil horizon and the effects of the construction technology. The main mission of the article is to supply a substantial time and a reliable basis that are needed by the vacuum-surcharge combined preloading method and the construction period. The main data sources are come from the ground treatment project of a cogeneration power plant in Zhuhai Guangzhou. We adopt the exponential curve fitting method and the method of Asaoka to count the degree of consolidation of the saturated soft clay soil.

scholarly journals Studi Aplikasi Vacuum Preloading Sebagai Metode Alternatif Percepatan Proses Konsolidasi pada Tanah Lempung Lunak Jenuh Air: Trial GVS pada Perumahan Pantai Indah Kapuk, Jakarta

2011 ◽  
Vol 2 (2) ◽  
pp. 1055 ◽  
Author(s):  
Andryan Suhendra ◽  
Masyhur Irsyam
Keyword(s):  
Soft Clay ◽  
Vacuum Preloading ◽  
Consolidation Process ◽  
Software Application ◽  
Alternative Method ◽  
Pump Pressure ◽  
Water Saturated ◽  
Reliability Monitoring ◽  
Water Tension ◽  
Saturated Soft Clay

Vacuum preloading is an alternative method to improve water-saturated soft clay by accelerating the consolidation process. A trial using GVS system was done at Pantai Indah Kapuk residence, Jakarta to investigate the system reliability. Monitoring equipments used include settlement plate to measure the consolidation decrease, piezometer to measure pore water tension, inklinometer to identify the soil direction and lateral movement during the vacuum preloading process, and manometer to measure the vacuum pump pressure. Analytical calculations to estimate the consolidation decrease is done using one-dimensional consolidation theory of Terzaghi. Besides, a numerical analysis is performed by element method up to Plaxis software application. Meanwhile, the monitoring results are achieved using Asaoka theory that estimates the achieved degree of reduction and consolidation. The monitoring results and theoretical analysis indicate that the GVS system included in the vacuum preloading method is quite reliable as an alternative method of consolidation acceleration of water-saturated soft clay. 

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