scholarly journals Design Method and Verification of Electroosmosis-Vacuum Preloading Method for Sand-Interlayered Soft Foundation

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yunliang Cui ◽  
Jianbo Tu ◽  
Xinquan Wang ◽  
Hongguo Diao ◽  
Qianru Ge

The design method of electroosmosis-vacuum preloading for soft foundation treatment is not systematic and complete, thereby restricting the application of the technology in engineering. A design method for the electroosmosis-vacuum preloading treatment of sand-interlayered soft foundation is therefore presented. A compressible electrical prefabricated vertical drain is developed, and a vacuum sealing and draining system is designed for the application of the electroosmosis-vacuum preloading in sand-interlayered soft foundation. Calculation formulas of site resistance considering the interlayer and interface resistivity of the electrode are established to design the power supply and electrical circuit. A simple numerical simulation method is proposed to predict the ground settlement treated by electroosmosis-vacuum preloading. A field test of electroosmosis-vacuum preloading is designed using the suggested method, and comparison tests between the electroosmosis-vacuum preloading and the vacuum preloading are performed to verify the proposed technique. The test results show that the proposed design method is reasonable for the design of electroosmosis-vacuum preloading in engineering.

2012 ◽  
Vol 226-228 ◽  
pp. 1359-1364
Author(s):  
Qi Xia Liu ◽  
Yang Zhao

The application of vacuum preloading for soft foundation treatment in grain storage is introduced from its principle, design, construction and the inspections. Its obvious effect is proved by example. The vacuum preloading method can effectively improve the soft soil foundation’s physical and mechanical performance and increase the bearing capacity of soft soil of coastal areas. For the grain storage, oil depot especially for large reserves of oil depot project, the treatment effect is remarkable. It can be widely used in the ground treatment in the soft soil area for grain storage, oil depot construction.


2015 ◽  
Vol 744-746 ◽  
pp. 589-592
Author(s):  
Y.Z. Bai ◽  
Jian Chen ◽  
Bei Cheng

Traditional vacuum preloading method has two drainage parts: 1) horizontal drainage part-sand cushion; 2) vertical drainage part-(Prefabricated vertical drain (PVD) and so on). During vacuum preloading process, the drainage effect of horizontal sand cushion is strong near stabilized soil surface and decreases rapidly at deeper position, while drainage range of vertical drain includes whole stabilized soil depth and its drainage ability is higher. So, it is important to improve the drainage design of vacuum preloading system to transmit vacuum head to vertical drain more efficiently. This paper presents a new vacuum preloading method-direct drainage vacuum preloading method (DDVP method). Compared with traditional vacuum preloading method, this system cancels horizontal drainage part-sand cushion and uses sealed pipe to directly connect with PVDs. Vacuum head can be transmitted into PVD without attenuation. Field test is applied to study the effect of slurry improvement of this method.


2012 ◽  
Vol 170-173 ◽  
pp. 3130-3134 ◽  
Author(s):  
Yun Liang Cui ◽  
Ming Jun Gao ◽  
Zhi Hao Liu

A lot of large area lands were made in China coastal areas by dredging sludge from the sea. The dredged fill ground had a very low bearing capacity which should be increased as soon as possible to meet the requirements of constructions. However, conventional vacuum preloading could not be used for this purpose because the sand cushion could not be laid on the sludge ground due to the very low bearing capacity. To solve this problem, a modified vacuum preloading method without sand cushion was proposed. This method has been successfully tested and applied in the reclamation project in Wenzhou. Based on this project, the technological process and the key technology were introduced and the reinforcement effect was analyzed. Project results showed the modified vacuum preloading method could achieve a good reinforcement effect on large area dredged fill ground in a short period. It is worth to promote the application of this method in coastal reclamation projects.


2012 ◽  
Vol 190-191 ◽  
pp. 1207-1213
Author(s):  
Qi Xia Liu ◽  
Yang Zhao

The application of vacuum preloading for soft foundation treatment in grain storage is introduced from its principle,design,construction and the inspections. Its obvious effect is proved by example. The east coast of China is the most developed economical area and major grain and oil manufacturers. Many grain and oil depots have been established. However, in the places where the depots located, soil is soft dirt with low strength grade, high compressibility, small permeability and high possibility of plastic flow, has increased difficulties of grain and oil depots foundation construction. Without enough knowledge of soft soil and lacking of proper foundation construction method and good technology, depots may slip due to foundation’s erosion, and big settlement. If the structure slips, equipments for aeration, dehumidifier, antivirus equipment cannot work well. Based on the statement above, reasonable and effective methods for soft soil foundation work is the key point for construction of high quality and high standard grain and oil depots. This paper mainly discussed when we do depots construction work on the soft soil foundation, exact calculation, construction method and result test of fasten method for the soft foundation under the vacuum circumstance of preloading.


2009 ◽  
Vol 12 (18) ◽  
pp. 76-84
Author(s):  
Phan Vo ◽  
Giang Thien Nguyen

The report will introduce a new technology using Prefabricated Horizontal Drain (called Super Board Drain -SBD) which is replaced for Sand Mat in soft soil treatment by using Prefabricated Vertical Drain (PVD) with preloading method and sand filled layer (Sand Mat) designed as the horizontal drainage for PVD through East-West Highway Construction Project.


2021 ◽  
Vol 4 (3) ◽  
pp. 641
Author(s):  
Steven Djunawan ◽  
Andryan Suhendra

Soft soil in Indonesia is problematic in infrastructure development because of its low bearing capacity and takes a long time to consolidate. In general, the method used to overcome soft soil is vacuum preloading combined with prefabricated vertical drain, PVD. The purpose of the initial loading is to consolidate the soft soil layer with a load equal to or greater than the soil load during and after construction. Meanwhile, vertical can support the consolidation process. However, this method can also cause lateral movement which also affects the area outside the repair. Thus, it is necessary to model the influence distance analysis from the circumference of the repair area outside the repair. Analysis and modeling using 2D finite program elements that will be compared with results in field. The results of the comparison of the settlement for 260 days shows a different chart pattern but a corresponding final settlement. The modeling shows that the largest influence distance due to the lateral movement is cell 2, which is 11,23mTanah lunak di Indonesia menjadi problematika pada pembangunan infrastruktur dikarenakan daya dukung yang rendah serta memakan waktu penurunan konsolidasi yang lama. Pada umumnya, perbaikan tanah yang digunakan untuk mengatasi tanah lunak adalah vacuum preloading yang dikombinasikan dengan prefabricated vertical drain, PVD. Tujuan pembebanan awal adalah untuk mengkonsolidasikan lapisan tanah lunak dengan beban sama atau lebih besar dari beban tanah selama dan setelah konstruksi. Sementara drainase vertikal dapat mempercepat proses konsolidasi. Namun, metode ini juga dapat penyebabkan pergerakan lateral yang juga mempengaruhi area diluar perbaikan. Sehingga, dibutuhkan pemodelan analisis jarak pengaruh dari keliling daerah perbaikan ke daerah luar perbaikan. Analisis dan pemodelan menggunakan program elemen hingga 2D yang akan dibandingkan dengan hasil lapangan. Hasil perbandingan penurunan selama 260 hari menunjukan pola grafik yang berbeda namun penurunan akhir yang sesuai. Pemodelan menunjukan jarak pengaruh terbesar akibat pergerakan lateral berada pada cell 2 yaitu 11,23m.


2020 ◽  
Vol 6 (2) ◽  
pp. 77-89
Author(s):  
Maulana Iqbal ◽  
Anton Soekiman

Permasalahan konstruksi jalan di atas tanah bermasalah (problematic soil) tanpa adanya perbaikan  tanah (soil improvement) maupun perkuatan tanah (soil reinforcement), pada umumnya akan mengakibatkan instabilitas timbunan dan penurunan tanah dasar. Tidak sedikit jaringan jalan di atas tanah dasar bermasalah di beberapa area di Indonesia mengalami penurunan tingkat pelayanan yang drastis sebelum umur rencana. Kurangnya pemahaman karakteristik tanah dasar menyebabkan pemilihan metode konstruksi tidak efektif dan efisien. Kecenderungan pemilihan metode yang digunakan masih didasari ketersediaan pagu anggaran. Pemilihan metode konstruksi jalan di atas tanah dasar bermasalah dengan analisis Case-Based Reasoning (CBR), dapat menghemat waktu dalam pengambilan keputusan berdasarkan keahlian pakar, sehingga risiko ketidakakuratan pemilihan metode berakibat pada keputusan penanganan yang kurang tepat dapat diminimalisir. Berdasarkan hasil analisis dengan mengambil studi kasus tol Pemalang – Batang pada kedalaman tanah bermasalah antara 10 sampai dengan 20 meter dan menggunakan analisis CBR, didapatkan  gejala kecocokan (similarity) sebesar 97,74% pada metode Prefabricated Vertical Drain (PVD) yang dikombinasikan dengan metode pembebanan dengan vakum (vacuum preloading) dan Prefabricated Horizontal Drain (PHD).


2021 ◽  
Vol 4 (2) ◽  
pp. 447
Author(s):  
Aditya Christiandi Sinulingga ◽  
Andryan Suhendra

The development of toll road or expressway infrastructure in Indonesia is urgently needed because it can reduce inefficiencies due to congestion on main sections, as well as to improve the process of distribution of goods and services, especially in areas with high levels of development. Transportation infrastructure development on soft soils often experiences consolidation decline problems. Soft soil has a high moisture content and low bearing capacity. If the soft soil is saturated with water, it means that the water cannot be fully dissipated, causing the soil to take a long time to consolidate. If the construction work does not begin with land improvement, the construction has the potential to suffer damage before the planned age. To anticipate this, an alternative that can be done is to repair the soil with prefabricated vertical drain (PVD) and vacuum preloading. This study aims to determine the degree of consolidation based on the piezometer reading and to make initial predictions. As for the results of this study there is a difference of 5.79% in the degree of assessment from the results of theoretical calculations with the piezometer reading.Pembangunan infrastruktur jalan tol atau jalan bebas hambatan di Indonesia sangat dibutuhkan karena dapat mengurangi inefisiensi akibat kemacetan pada ruas utama, serta untuk meningkatkan proses distribusi barang dan jasa terutama di wilayah yang sudah tinggi tingkat perkembangannya. Pembangunan infrastruktur transportasi pada tanah lunak sering mengalami masalah penurunan konsolidasi. Tanah lunak memiliki kadar air yang tinggi dan daya dukung yang rendah. Jika tanah lunak jenuh air mengakibatkan air tidak dapat terdispasi secara penuh menyebabkan tanah membutuhkan waktu yang lama untuk terkonsolidasi. Apabila pekerjaan konstruksi tidak diawali dengan perbaikan tanah maka konstruksi tersebut berpotensi mengalami kerusakan sebelum umur yang telah direncanakan. Untuk mengantisipasi hal tersebut alternatif yang dapat dilakukan adalah melakukan perbaikan tanah dengan prefabricated vertical drain (PVD) dan vacuum preloading. Penelitian ini bertujuan untuk mengetahui besar derajat konsolidasi berdasarkan pembacaan piezometer serta melakukan prediksi awal. Adapun hasil dari penelitian ini terdapat perbedaan 5,79% derajat konsolidasi dari hasil perhitungan teoritis dengan pembacaan piezometer.


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