scholarly journals Analisis Alternatif Perbaikan Tanah Lunak dan Sangat Lunak pada Jalan Tol

2020 ◽  
Vol 3 (4) ◽  
pp. 1137
Author(s):  
Christian Eka Putra ◽  
Chaidir Anwar Makarim
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
High Water Content ◽  
Vacuum Preloading ◽  
Consolidation Process ◽  
Toll Road ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain

The existence of soft soil is one of the problems in the field of construction. Soft soil is soil that has high water content and low carrying capacity. In the case of this toll road, soil investigation at the site shows that the subgrade in the toll road planning is soft clay soil to a depth of 32 meters so that soil improvement is needed. High landfill built on soft subgrade without reinforcement will experience landslides. So it is necessary to strengthen the landfill and repair the subgrade to prevent road slides. The soil improvement methods in use are vacuum preloading and Prefabricated Vertical Drain with the vacuum functioning as an additional load. In addition to accelerating the consolidation process, the vacuum can also reduce the height of the embankment needed to achieve the desired planned road elevation. Strengthening with geotextile is also carried out on the landfill with a height of 5.94 meters so that there is no landslide on the fill. Using soil improvement methods such as vacuum preloading and prefabricated vertical drain will increase the bearing capacity of the soil so that differences in bearing capacity occur before and after repair. AbstrakKeberadaan tanah lunak menjadi salah satu masalah dalam bidang konstruksi. Tanah lunak adalah tanah yang memiliki kadar air yang tinggi dan daya dukung yang rendah. Pada kasus jalan tol ini, penyelidikan tanah di lokasi menunjukan bahwa tanah dasar pada perencanaan jalan tol merupakan tanah lempung lunak hingga kedalaman 32 meter sehingga dibutuhkan perbaikan tanah dasar. Timbunan tinggi yang dibangun di atas tanah dasar lunak tanpa perkuatan akan mengalami kelongsoran. Sehingga diperlukan perkuatan timbunan dan perbaikan tanah dasar untuk mencegah kelongsoran jalan. Metode perbaikan tanah yang digunakan adalah vacuum preloading dan Prefabricated Vertical Drain dengan vacuum berfungsi sebagai beban tambahan. Selain mempercepat proses penurunan, vacuum juga dapat mengurangi tinggi timbunan yang dibutuhkan untuk mencapai elevasi jalan rencana yang diinginkan. Perkuatan dengan geotextile juga dilakukan pada timbunan dengan tinggi yang mencapai 5.94 meter supaya tidak terjadi kelongsoran pada timbunan tersebut. Dengan menggunakan metode perbaikan tanah berupa vacuum preloading dan prefabricated vertical drain akan meningkatkan daya dukung tanah sehingga akan diketahui perbedaan daya dukung yang terjadi sebelum dan sesudah diperbaiki.

scholarly journals Numerical Modelling of Prefabricated Vertical Drain for Soft Clay Using ABAQUS

2015 ◽  
Vol 773-774 ◽  
pp. 1502-1507
Author(s):  
Saiful Azhar Ahmad Tajudin ◽  
Mohd Fairus Yusof ◽  
I. Bakar ◽  
Aminaton Marto ◽  
Muhammad Nizam Zakaria ◽  
...  
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soft Clay ◽  
Elastic Model ◽  
Clay Layer ◽  
Soil Consolidation ◽  
Consolidation Process ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain

Construction, buildings and infrastructure founded on soft clays are often affected by settlement problem. Therefore, Prefabricated Vertical Drain (PVD) is one of the best solutions to accelerate soil consolidation by shortening the drainage path. In this study, numerical investigation was carried out to pursue a better understanding of the consolidation behavior of soft clay improved with PVD. The consolidation process accelerated by PVD with surcharge of 50 kPa was analysed using the ABAQUS software by adopting an elastic model. The aim of this study is to compare the settlement and the required time to fully consolidate the soft soil at different drain spacings (1.0 m, 1.5 m and 2.0 m) for two different thickness of the clay layer. The results shows that the time required to completely consolidate the soft soil for 12 m and 20 m thickness of clay layer with different spacings are in the range of 3 months to 66 months. The settlement rate and excess pore water pressure dissipation are increased when the spacing of the drain closer.

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 ANALISIS PENGARUH METODE PERBAIKAN TANAH VACUUM PRELOADING TERHADAP STRUKTUR ABUTMENT DI SEKITARNYA

2021 ◽  
Vol 4 (3) ◽  
pp. 641
Author(s):  
Steven Djunawan ◽  
Andryan Suhendra
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Infrastructure Development ◽  
Lateral Movement ◽  
Vacuum Preloading ◽  
Consolidation Process ◽  
Distance Analysis ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Long Time

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.

scholarly journals ANALISIS DERAJAT KONSOLIDASI BERDASARKAN HASIL PEMBACAAN PIEZOMETER PADA PROYEK TOL TRANS SUMATERA

2021 ◽  
Vol 4 (2) ◽  
pp. 447
Author(s):  
Aditya Christiandi Sinulingga ◽  
Andryan Suhendra
Keyword(s):  
Theoretical Calculations ◽  
Soft Soil ◽  
Infrastructure Development ◽  
Vacuum Preloading ◽  
Goods And Services ◽  
Toll Road ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Long Time ◽  
Degree Of Consolidation

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.

Research on Surface-Layer Improvement Technology for Dredger Fill by Vacuum Preloading

2012 ◽  
Vol 256-259 ◽  
pp. 1703-1706
Author(s):  
Yan Hua Yang ◽  
Fu Quan Ji ◽  
Zhao Yang
Keyword(s):  
Large Scale ◽  
Soft Soil ◽  
Soft Clay ◽  
Drainage System ◽  
High Water ◽  
Soil Improvement ◽  
High Water Content ◽  
Construction Technology ◽  
Vacuum Preloading ◽  
Reclaimed Land

The surface-layers have very high water content and low bearing capacity, so far to be the very soft clay foundation, which come from the reclaimed land in project of reclamation. It is difficult to improve the very soft clay foundation by traditional vacuum preloading. A new method named surface soft soil improvement is presented in this paper, which can make the soft clay foundation to be improved in preliminary. Once forming the hard coat layer, the foundation may reach the needs of further construction. In the construction technology, the horizontal filter pipe net is used to instead of the sand bedding course. By laying of woven cloth and non-woven geotextile over the surface of reclaimed silt, installing PVDs by manpower becomes possible. Besides, the vertical PVDs all are connected with the horizontal filter pipe net directly, that makes a whole spatial drainage system. The loss of the degree of vacuum is decreased, and the improvement is increased. Thus, this construction technology is as a reference to the large scale engineering construction and similar projects.

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 PENURUNAN OPRIT JEMBATAN SEMARANG LINGKAR UTARA DAN JEMBATAN KALI JAJAR DEMAK JAWA TENGAH DENGAN PRE-FABRICATED VERTICAL DRAIN

2021 ◽  
Vol 4 (1) ◽  
pp. 27
Author(s):  
M Zaki ◽  
Wardani SPR ◽  
Muhrozi Muhrozi
Keyword(s):  
Bearing Capacity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soil Improvement ◽  
Unit Weight ◽  
Fast Time ◽  
Foundation Soil ◽  
Vertical Drain ◽  
Long Time

<p><em>Construction on soft soil, often creates problems. The Semarang North Ring Bridge and Kali Jajar Bridge are the Recent soft Marine Alluvium zones located in the Pantura area which have very soft soil characteristics with a depth of more than -30.0 meters this has resulted in a very large settlement due to very small grains, flood, rob, pore water pressure increases so that the shear strength of the soil will be small, the compression is large and the permeability coefficient is small so that if the construction load exceeds the critical bearing capacity, the damage to the foundation soil will occur. To get the increase in soil bearing capacity, it can be achieved by changing the properties of the soil from the shear angle (</em>f<em>), cohesion (c) and unit weight (</em>g<em>). The settlement can be reduced by increasing the cavity density from the compression of the soil particles (Wesley, 1977). Soil improvement takes a long time, aiming to increase shear resistance so that it requires a fast time in this case is to use Pre-Fabricated Vertical Drain (Bowles 1981). The results of the analysis of the pattern of decline and the effectiveness of the use of PVD (pre-fabricated vertical drain) at the Oprit Bridge in the two research locations have the same decrease in the range of the same heap height at (H = 4 meters) there is a decrease of 117.53 cm at 64 months on the bridge. Kali Jajar (STA. 3 + 200) and there was a decrease of 268.94 cm at 37 months at the Semarang North Ring Bridge</em></p>

scholarly journals PERANCANGAN EFEKTIVITAS PERBAIKAN TANAH DENGAN MENGGUNAKAN METODE PREFABRICATED VERTICAL DRAIN

2020 ◽  
Vol 3 (2) ◽  
pp. 110
Author(s):  
Priscilla Azzahra Chairani
Keyword(s):  
Laboratory Test ◽  
Clay Soil ◽  
Soil Improvement ◽  
Soil Parameters ◽  
Soil Consolidation ◽  
Consolidation Process ◽  
Vertical Drain ◽  
Laboratory Test Results ◽  
Prefabricated Vertical Drain ◽  
Unfavorable Condition

<p><em>As a country that surrounded by active volcanoes, Indonesia has a very diverse clay soil content. However, in reality, clay soil is an unfavorable condition for construction activities because of its low-level of stability. Therefore, when the clay soil receives a static load on it, the soil will slowly have a settlement due to the dissipation of pore water. This settlement usually occurs over a very long period of time, thus, it is necessary to do the soil improvement using Prefabricated Vertical Drain (PVD) combined with preloading in order to shorten the time of soil consolidation so that the consolidation process becomes faster. Soil settlement analysis is calculated using two soil parameters derived from the NSPT correlation data and laboratory test data to determine the most efficient soil parameters. Furthermore, a theoretical soil improvement analysis was carried out by comparing Baron's theory and Hansbo's theory and using the Settle3D analysis program. The analysis results show that the calculation of consolidation settlement using soil parameters from laboratory test results has the closest value to the actual results in the field with a efficiency of 91%. Meanwhile, for soil improvement, the most effective PVD design was chosen using the Hansbo theory with a triangular installation pattern and a spacing of 150 cm combined with a gradual embankment.</em></p>

Formation mechanism of clogging of dredge slurry under vacuum preloading by using digital image technology

2021 ◽  
Author(s):  
Honglei Sun ◽  
Zili He ◽  
Xueyu Geng ◽  
Mengfen Shen ◽  
Yuanqiang Cai ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Discharge Rate ◽  
Soft Clay ◽  
Vacuum Pressure ◽  
Water Volume ◽  
High Water Content ◽  
Volume Discharge ◽  
Vacuum Preloading ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains

Vacuum preloading combined with prefabricated vertical drains (PVDs) system has been widely used to improve the soft clay with high water content. Clogging is usually formed around the PVDs during the vacuum preloading, impeding the propagation of the vacuum pressure and slowing down the consolidation process. In order to understand the forming mechanism of the clogging, particle image velocimetry (PIV) technique and particle tracking velocimetry (PTV) technique were adopted in the model test of vacuum preloading test. Through this study, three stages can be identified from the results of water volume discharge rate and maximum displacements versus time. In the first stage, the soil around the PVD is horizontal consolidated, which leads to the rapid formation of clogging. In the second stage, the formation of clogging slows down due to the loss of vacuum pressure, which further reduces the drainage. In the third stage, the clogging tends to be stable, and the drainage consolidation rate is significantly reduced. PTV results show that there is difference in the displacement of large and small particles during improvement. Two methods were proposed to estimate the thickness of clogging zone, reflecting a growing layer of clogging zone compressed around the PVD. This study provides new insights to investigate the formation mechanism of clogging during vacuum preloading test.

scholarly journals THE ANALYSIS OF HORIZONTAL DRAIN DESIGN IN SOFT SOIL REINCFORCEMENT

CERUCUK ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 35
Author(s):  
Hafiz Firmansyah ◽  
M. Afief Ma'ruf
Keyword(s):  
Soft Soil ◽  
Fine Sand ◽  
Soil Improvement ◽  
Quality Cost ◽  
Horizontal Drain ◽  
Vertical Drain ◽  
Access Road ◽  
Port Access ◽  
Prefabricated Vertical Drain ◽  
Horizontal Drainage

To help the process of consolidation of the soil, On the port access road Trisakti using Prefabricated Vertical Drain (PVD) materials. Of the work (PVD) thing to note is the horizontal drainage, because it was feared the absence of Horizontal Drain work item function of PVD become non-optimal even it might does not work, so the necessary design analysis of Horizontal Drain that can be used on the project. Analysis of Horizontal Drain design is intended to get the Horizontal Drain design alternatives the most optimal based on quality, cost and time.The methods used in the analysis of the design of Horizontal Drain this is a soft soil improvement method using PVD with attention to soil degradation and the planning of the heap.In the design of the installation of PVD method using static, obtained the degree of consolidation of 90% takes 9.33 months. The calculation of Horizontal Drain in the discharge value must be in flush in one horizontal drain line is  (minimum permeability). From the results of the analysis there is some material horizontal drain of qualified (in terms of time, cost and quality of workmanship) then get : Rough sand (10.93, Rp. 24.050.000.000,-, and 9.4 months), Fine sand (16.24, Rp-16,835,000,000.0, and 9.4 months), PHD (Horizontal Prefabricated Drain) (74.01, Rp-13,101,140,000.0, and 5.6 months) so that it can be concluded that the material PHD (Horizontal Prefabricated Drain) the most efficient in terms of quality, cost, and time. Keywords: Consolidation, Degrees of consolidation, Horizontal Drain, Preloading, Prefabricated Vertical Drain (PVD), Prefabricated Horizontal Drain (PHD).

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