scholarly journals Analysis of Soft Soil Consolidation with the Application of Prefabricated Vertical Drains with Preloading Method Using Fem / Analiza Konsolidacji Słabych Gruntów Przy Uzyciu Metody Elementów Skonczonych

2011 ◽  
Vol 57 (1) ◽  
pp. 17-25 ◽  
Author(s):  
K. Binder
Keyword(s):  
Finite Element Method ◽  
Soft Soil ◽  
Two Dimensional ◽  
Soil Consolidation ◽  
Dimensional Solution ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
One Dimensional ◽  
Preloading Method ◽  
Consolidation Time

Abstract The article presents the application of finite element method for estimating settlements of road embankments founded on the soil reinforced with vertical drains and preloading method. The idea of the method was the transition from the solution of one-dimensional consolidation proposed for two-dimensional solution, while maintaining the same consolidation time and comparison with results obtained from measurements settlements of road embankment which is a part of planned Gdansk Southern Ring Road near Przejazdowo site.

scholarly journals ANALISIS PENGGUNAAN PREFABRICATED VERTICAL DRAINS (PVD) PADA TANAH LEMPUNG LUNAK YANG TERDAPAT LAPISAN LENSA

2020 ◽  
Vol 3 (1) ◽  
pp. 119
Author(s):  
Andreyan Prasetio ◽  
Aniek Prihatiningsih
Keyword(s):  
Soft Soil ◽  
Soil Improvement ◽  
Cohesive Soils ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains ◽  
Soil Layers ◽  
Vertical Drains ◽  
Vertical Drain ◽  
Installation Depth ◽  
Consolidation Time

Problem that often occurs in soft cohesive soils is settlement caused by consolidation process. If  construction activities doing when the soils has not been consolidated, settlement can occur. To accelerate  the consolidation process, soil improvement are usually do, one method of soil improvement to accelarate the consolidation process is vertical drain using prefabricated vertical drains (PVD). The soft soil layers in the field are not always continuous, sometimes found soft soil layers that have a lens layer. In this study, will discuss about the settlement and consolidation time of soft  soil layers that have a lens layer which has been improved by PVD with 1 meter distance. Infrastructure that stand on a location that is installed by PVD is taxiway and loading by Airbus A380 aircraft of 18,22ton/m2. Analysis using the 1 dimensional consolidation theory of Terzaghi. For PVD installation to a depth of 50 meters, preloading settlement of 234,80 cm with a consolidation time of  2260 days for the square pattern PVD and 1918 days for triangle pattern PVD. Post loading settlement for PVD installation depth of 50 meters by 2,50 cm. AbstrakMasalah yang sering terjadi pada tanah kohesif dan lunak adalah penurunan yang disebabkan proses konsolidasi. Penurunan dapat menyebabkan keretakan pada struktur konstruksi yang berada di atasnya. Jika suatu kegiatan konstruksi dilakukan saat tanah belum terkonsolidasi, maka konstruksi tersebut dapat mengalami penurunan.. Untuk mempercepat proses konsolidasi biasanya dilakukan perbaikan tanah, salah satu metode perbaikan tanah untuk mempercepat proses konsolidasi yaitu vertical drain dengan menggunakan prefabricated vertical drains (PVD). Lapisan tanah lunak yang terdapat di lapangan tidak selalu kontinu, terkadang ditemukan lapisan tanah lunak yang terdapat lapisan lensa. Pada penelitian ini, penulis akan membahas mengenai waktu konsolidasi yang dibutuhkan oleh lapisan tanah kohesif dan lunak yang terdapat lapisan lensa yang telah diperbaiki dengan menggunakan PVD berjarak 1 meter. Infrastruktur yang berdiri di atas lokasi yang dipasang PVD berupa taxiway dengan beban berupa pesawat Airbus A380 sebesar 18,22 ton/m2. Analisis dilakukan menggunakan teori konsolidasi 1 dimensi Terzaghi. Untuk pemasangan PVD hingga kedalaman 50 meter diperoleh penurunan pra pembebanan sebesar 234,80 cm dengan waktu konsolidasi selama 2260 hari untuk pemasangan PVD pola persegi dan selama 1918 hari untuk pola segitiga . Penurunan pasca pembebanan untuk pemasangan PVD hingga kedalaman 50 meter sebesar 2,5 cm.

scholarly journals Effect of Well Resistance on Time Factor Ratio Due to PVD Deformation

2021 ◽  
Vol 7 (3) ◽  
pp. 299
Author(s):  
Galuh Chrismaningwang ◽  
Hary Christady Hardiyatmo ◽  
Agus Darmawan Adi ◽  
Teuku Faisal Fathani
Keyword(s):  
Discharge Capacity ◽  
Soft Soil ◽  
Longitudinal Direction ◽  
Time Factor ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Factor Ratio ◽  
Confining Pressures ◽  
Considerable Impact ◽  
Consolidation Time

One of the most common soft soil enhancement techniques used to expedite the consolidation time significantly is Prefabricated Vertical Drains (PVD). This technique needs a sufficient discharge capacity value because it primarily functions as a drainage channel. The deformation of PVD is considered as one of the primary factors which affect discharge capacity. Therefore, this research determined the influence of upper-side deformation on PVD's discharge capacity (qw) using a specific design apparatus known as ASTM D4716, which manages the determination of transmissivity and flow rate at the longitudinal direction of geosynthetics. Furthermore, two PVD samples with dimensions of 3 and 4 mm thickness, 100 mm width, and 1000 mm length were examined under straight and buckled conditions. Stepwise confining pressures from 50 to 200 kPa were subjected to the samples under hydraulic gradients with values of 0.2, 0.5, and 1.0. The results showed that samples with greater thickness had higher discharge capacity, which significantly reduced in the lower hydraulic gradient. The deformation on the upper side of PVD induced a decrease of discharge capacity by approximately 13-16%, which led to a delay in the consolidation time. The discharge capacity values obtained from the experiments were employed as parameters in a time factor ratio of Th,w/Th. The analysis results show that the buckled PVD has a more considerable consolidation time due to the increase in the Th,w/Th ratio, with a discharge capacity value below 10-4 m3/s. It can be concluded that the deformation in the form of buckled conditions on the upper side of PVD had a considerable impact on PVD effectiveness.

Solutions of Technical Problems in Ultra-Soft Soil Improving Projects

2013 ◽  
Vol 275-277 ◽  
pp. 1398-1402
Author(s):  
Yong Hua Cao ◽  
Chang Quan Yin
Keyword(s):  
Building Materials ◽  
Soft Soil ◽  
Soil Improvement ◽  
New Method ◽  
Vacuum Preloading ◽  
Typical Application ◽  
Prefabricated Vertical Drains ◽  
Technical Problems ◽  
Vertical Drains ◽  
Preloading Method

Ultra-soft soil improvement projects are new trend in present China because of the limitation of construction period. Technical problems occur when traditional vacuum preloading method is applied for ultra-soft soil. This paper firstly gave an analysis of the main technical problems which include construction channel problems for building materials and workers, portion division problems of project area, installation problems of prefabricated vertical drains and formation problems of horizontal drainage cushion. Then solutions for these problems were presented. Based on the solutions and traditional vacuum preloading method, a new method for ultra-soft soil improving was put forward. A typical application of this new method was give at the end of this paper.

scholarly journals Ground settlement prediction of embankment treated with prefabricated vertical drains in soft soil

2018 ◽  
Vol 195 ◽  
pp. 03014
Author(s):  
Siswoko Adi Saputro ◽  
Agus Setyo Muntohar ◽  
Hung Jiun Liao
Keyword(s):  
Numerical Study ◽  
Soft Soil ◽  
Soil Permeability ◽  
K Value ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Prefabricated Vertical Drain ◽  
Actual Settlement ◽  
Final Settlement ◽  
Best Fit

Excessive settlement due to consolidation can cause damage to the structure’s rest on soft soil. The settlement takes place in relatively longer. The preloading and prefabricated vertical drain (PVD) is often applied to accelerate the primary settlement. The issue in this research is the estimation of the settlement. The Asaoka method and the finite element method using PLAXIS-2D are used to estimate the final settlement of a PVD treated embankment. For the former, a complete record of the settlement was required; for the latter, some ground parameters are needed for the PLAXIS-2D analysis, such as the permeability of the soil. Because the installation process of PVD tends to influence the permeability of the in-situ soil around the PVD, the soil permeability after the installation of PVD needs to be adjusted. The numerical results were compared with actual settlement data to find out the best-fit input parameters (i.e. soil permeability) of the actual data. It was found that the best-fit soil permeability (k) used in the numerical study was about one-half of the k value determined from the laboratory test. The Root Mean Square Deviation shows that the settlement predicted by the numerical analysis has approximately 30% of the actual settlement.

scholarly journals An educational software for teaching soil consolidation

2017 ◽  
Author(s):  
Gonzalo García Ros ◽  
Manuel Cánovas Vidal ◽  
Juan Francisco Sánchez Pérez ◽  
Iván Alhama Manteca
Keyword(s):  
Educational Software ◽  
Low Cost ◽  
Surface Settlement ◽  
Excess Pore Pressure ◽  
Soil Consolidation ◽  
Depth Of Penetration ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Graphical Environment

The educational tool SICOMED_3D has been created to simulate problems of soil consolidation by prefabricated vertical drains. Thanks to its nice interface of windows, the introduction of data is very fast and easy for the students, while providing users with simple handling and powerful calculations. Its graphical environment allows to get representations of the excess pore pressure, local settlements and total surface settlement. SICOMED_3D can also generate an animation that recreates the evolution of the surface settlement during the consolidation process. The software presents, like commercial softwares, the most common options (e.g., save and open cases files, save animations and representations, etc.). Although the program is created to be used in several fields, among others as an engineering or research tool, the main use of interest for this work is for educational purposes. Another important application is as low-cost laboratory practices, as students can experiment by modifying the soil properties, including the depth of penetration of the vertical drain, in a quick, simple and intuitive way.

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