scholarly journals METODE VACUUM CONSOLIDATION DENGAN PRELOADING UNTUK MEMPERCEPAT KONSOLIDASI TANAH PADA PERUMAHAN DI TANGERANG

2021 ◽  
Vol 4 (1) ◽  
pp. 171
Author(s):  
Jason Sastilaya ◽  
Gregorius Sandjaja Sentosa
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Drainage System ◽  
Soil Condition ◽  
Soil Improvement ◽  
Soil Conditions ◽  
Soil Plasticity ◽  
Calculation Results ◽  
Long Time

The expansion of housing in big cities cannot be denied given the rapid population growth in Indonesia. One of the areas that is currently expanding housing is Kosambi City, Tangerang. Soil conditions in Kosambi City are soft soil with high moisture content and soil plasticity, low permeability and soil bearing capacity, and high pore water pressure. This soft soil condition makes the consolidation decline take a very long time. To overcome the problem of the length of time for this consolidation settlement, it is necessary to improve the land. Soil improvement is being carried out, namely the method of vaccum consolidation with preloading. The combination of these methods is carried out by installing a vertical drainage system in the form of prefabricated fabricated drain (PVD) in soft soil, then the initial load is given in the form of preloading on the soil. The calculation results show that the amount of consolidation reduction that occurs when clay soil is loaded with a stockpile of 1.2 m high, a water surcharge of 1.3 m and a vaccum load is 0.3929 m and 0.6968 m for 85 years. The combined method of preloading and PVD is proven to be able to accelerate the time of consolidation, where Preloading and PVD are installed in a triangle pattern between 0.80 m to a depth of 12 m, capable of achieving a consolidation degree of 90% within 8 weeksPerluasan perumahan di kota besar tentu tidak dapat dipungkiri mengingat pesatnya pertumbuhan penduduk di Indonesia. Salah satu daerah yang sedang dilakukan perluasan perumahan yaitu Kosambi City, Tangerang. Kondisi tanah di Kosambi City merupakan tanah lunak dengan kadar air dan plastisitas tanah yang tinggi, permeabilitas dan daya dukung tanah yang rendah, serta tingginya tekanan air pori. Kondisi tanah lunak ini membuat penurunan konsolidasi membutuhkan waktu yang sangat lama. Untuk mengatasi masalah lamanya waktu penurunan konsolidasi ini, perlu dilakukan perbaikan tanah. Perbaikan tanah yang dilakukan yaitu metode vaccum consolidation dengan preloading. Kombinasi pada metode ini dilakukan dengan cara memasang sistem drainase vertikal berupa prefabricated fabricated drain (PVD) di dalam tanah lunak, kemudian diberikan beban awal yaitu berupa timbunan (preloading) pada tanah tersebut. Hasil perhitungan menunjukkan besar penurunan konsolidasi yang terjadi jika tanah lempung dibebani dengan timbunan setinggi 1,2 m, water surcharge setinggi 1,3 m dan beban vaccum  adalah 0,3929 m dan 0,6968 m selama 85 tahun. Metode kombinasi preloading dan PVD terbukti mampu mempercepat waktu konsolidasi, dimana Preloading dan PVD dipasang dengan pola segitiga berjarak 0,80 m hingga kedalaman 12 m, mampu mencapai derajat konsolidasi 90% dalam waktu 8 minggu. 

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>

Experimental Research of Soft Soil Ground Treatment in Yangpu Port by Static-Dynamic Drainage Consolidation

2013 ◽  
Vol 353-356 ◽  
pp. 203-207
Author(s):  
Yong Kang Yang ◽  
Wu Yang ◽  
Chun Yan Feng
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Drainage System ◽  
Physical And Mechanical Properties ◽  
High Water ◽  
Surface Settlement ◽  
High Water Content ◽  
Engineering Practice ◽  
Ground Treatment

Yangpu Port has inhomogeneous soft soil with the properties of high water content, high void ratio, high compressibility and low shear strength. Based on soft soil ground treatment engineering practice, the geological characteristics are summarized, the ground treatment methods are comparatively analyzed, static-dynamic drainage consolidation method is chosen to treat the soft soil ground, the reinforcing mechanism of vertical and horizontal drainage system are discussed, the design of drainage system, preloading and dynamic consolidation are researched and the surface settlement monitoring, pore water pressure monitoring, side piling displacement monitoring, laboratory soil test and plate loading tests are carried out. The results show that average surface settlement is 1170.8 mm, the physical and mechanical properties of soft soil are improved and the characteristic value of foundation bearing capacity is greater than 120kPa.

Research on Mechanism of Consolidating the Saturated Soft Clay with the Application of Pile-Supported Composite Foundation

2012 ◽  
Vol 594-597 ◽  
pp. 370-375
Author(s):  
Zhao Hua Zhang
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soft Clay ◽  
Drainage System ◽  
Single Layer ◽  
Composite Foundation ◽  
Critical Height ◽  
The Stability ◽  
Saturated Soft Clay

In order to reduce both uneven settlements and construction duration, researches on pile-supported composite foundation of highway were carried out. When the groundfill is higher than the critical height（1.35 times space between piles）, a complete geostatic arch is formed in the pile-supported composite foundation, which could significantly reduce the uneven settlement. Grids installed at the bottom of embankment could markedly reduce the side displacement and increase the stability of embankment, multilayer grids with layout of loose on the top and dense at the bottom prefer to single layer grids. Plastic drainage board makes up well-functioned drainage system, which can shorten the dispersal time of pore water pressure and accelerate the consolidation of soft soil to shorten the construction duration.

scholarly journals Pengaruh Kurva Histeresis Terhadap Model Stabilitas Lereng Timbunan Akibat Kegiatan Pertambangan Di Zona Lahan Basah

2017 ◽  
Author(s):  
Reza Adhi Fajar ◽  
Lilik Eko Widodo ◽  
Gunawan Handayani ◽  
Tedy Agung Cahyadi
Keyword(s):  
Vadose Zone ◽  
Water Saturation ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Hysteresis Curve ◽  
Soil Conditions ◽  
Residual Soil ◽  
Complex Issue ◽  
Additional Reference

Landfill of residual soil due to mining activity in the wetland area is a relatively complex issue due to the soft soil conditions that are vulnerable to landslides. The stabilization method to increase the safety factor from landslide hazard can be done by decreasing the degree of water saturation in the soil disposal. In this case, the dominant mechanical parameters used in slope stability analysis will be elaborated with the SWCC concept for soft soil. While the conceptual model is built, it is based on the phenomenon of negative pore water pressure that appears in the vadose zone on the groundwater surface. The information provided from the hysteresis curve configuration can be used as an additional reference for the optimistic disaster analysis

The effect of pore-water pressure on NATM tunnel linings in decomposed granite soil

2005 ◽  
Vol 42 (6) ◽  
pp. 1585-1599 ◽  
Author(s):  
J H Shin ◽  
D M Potts ◽  
L Zdravkovic
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Drainage System ◽  
Tunnel Lining ◽  
Natm Tunnel ◽  
Decomposed Granite ◽  
Secondary Lining ◽  
Granite Soil ◽  
Functional Components

Tunnelling in a water bearing soil often produces a long-term interaction between the tunnel lining and the surrounding soil. With respect to lining design, infiltration and external pore-water pressures are often one of the most important factors to be considered. Development of pore-water pressure may accelerate leakage and cause deterioration of the lining. This can be particularly troublesome to structural and functional components of the tunnel and can often lead to structural failure. However, as a result of the complicated hydraulic boundary conditions and the long times often required for pore pressure equilibration, research on this subject is scarce. Consequently, most design approaches deal with the effects of pore-water pressure on the tunnel lining in a qualitative manner. In this paper, the development of pore-water pressure and its potential effects on the tunnel lining are investigated using the finite element method. In particular, the deterioration of a drainage system caused by clogging is considered. It is shown that the development of pore-water pressure on the lining is dependent on the lining permeability and the deterioration of the drainage system, particularly for a tunnel with both a primary and a secondary lining. The magnitude of pore-water pressure on a new Austrian tunnelling method (NATM) tunnel constructed in decomposed granite soil and the effect of tunnel shape are investigated. Design curves for estimating pore-water pressure loads on a secondary lining are proposed.Key words: numerical analysis, tunnel lining, decomposed granite.

Geosynthetic Encased Column: comparison between numerical and experimental results

2021 ◽  
Vol 44 (4) ◽  
pp. 1-12
Author(s):  
Nima Alkhorshid ◽  
Gregório Araújo ◽  
Ennio Palmeira
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Improvement ◽  
Soft Soil ◽  
Experimental Tests ◽  
High Permeability ◽  
Soft Soils ◽  
Column Comparison ◽  
Surrounding Soil ◽  
Granular Column

The use of granular column is one of the ground improvement methods used for soft soils. This method improves the foundation soils mechanical properties by displacing the soft soil with the compacted granular columns. The columns have high permeability that can accelerate the excess pore water pressure produced in soft soils and increase the undrained shear strength. When it comes to very soft soils, the use of granular columns is not of interest since these soils present no significant confinement to the columns. Here comes the encased columns that receive the confinement from the encasement materials. In this study, the influence of the column installation method on the surrounding soil and the encasement effect on the granular column performance were investigated using numerical analyses and experimental tests. The results show that numerical simulations can reasonably predict the behavior of both the encased column and the surrounding soil.

scholarly journals Perbandingan Pengujian Konsolidasi Menggunakan Alat Rowe Cell dan Oedometer pada Tanah Lanau Lunak

2020 ◽  
Vol 22 (2) ◽  
pp. 149-155
Author(s):  
Iskandar ◽  
Rabiya
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soil Samples ◽  
Soil Parameters ◽  
Soil Consolidation ◽  
Test Results ◽  
Soft Soils ◽  
Better Than ◽  
Rowe Cell

Soil consolidation testing using an oedometer and rowe cell. Oedometers are often used on clay and soft soils. However, in the development of the rowe cell device, the results of lowering soft soil were better than the oedometer. The advantage of this rowe cell is that it can determine the saturation value of the soil samples tested. The rowe cell tester can measure the pore water pressure at the beginning and end of each consolidation stage. This rowe cell can provide suitable settlement for soft soils. This consolidation test to obtain soil parameters such as Cv and Cc by using the rowe cell tool. After that, from the test results, the two tools were compared.

Study on Artificial Island Ground Improvement Method and Effect

2014 ◽  
Vol 1030-1032 ◽  
pp. 1037-1040
Author(s):  
Jin Fang Hou ◽  
Ju Chen ◽  
Jian Yu
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Improvement ◽  
Soft Soil ◽  
Horizontal Displacement ◽  
Treatment Method ◽  
Surcharge Preloading ◽  
Porosity Ratio ◽  
Improvement Method ◽  
Consolidation Degree

The artificial island ground on an open sea is covered by thick soft soil. It must be improved before using. In accordance with a designing scheme, the ground treatment method is inserting drain boards on land and jointed dewatering surcharge preloading, the residual settlement is not more than 30cm after improvement and the average consolidation degree is more than 85%. In order to estimate ground improvement effect and construction safety, instruments are buried to monitor the whole ground improving processes. By monitoring settlement and pore water pressure, it is shown that the total ground settlement in construction is 2234mm, its final settlement is 2464mm, and consolidation degree and residual settlement respectively satisfy requirements. In ground improvement, horizontal displacement is small and construction is safe. Meanwhile, the results of soil properties and vane shear strength detection tests show the soft soil ground is greatly reduced in water content and porosity ratio, and improved in strength. It is named that the ground improvement method is reasonable and reaches expected effect.

Coefficients of active earth pressure with seepage effect

2012 ◽  
Vol 49 (6) ◽  
pp. 651-658 ◽  
Author(s):  
Pérsio L.A. Barros ◽  
Petrucio J. Santos
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Retaining Wall ◽  
Drainage System ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Earth Pressure ◽  
Friction Angle ◽  
Active Earth Pressure ◽  
Plane Failure

A calculation method for the active earth pressure on the possibly inclined face of a retaining wall provided with a drainage system along the soil–structure interface is presented. The soil is cohesionless and fully saturated to the ground surface. This situation may arise during heavy rainstorms. To solve the problem, the water seepage through the soil is first analyzed using a numerical procedure based on the boundary element method. Then, the obtained pore-water pressure is used in a Coulomb-type formulation, which supposes a plane failure surface inside the backfill when the wall movement is enough to put the soil mass in the active state. The formulation provides coefficients of active pressure with seepage effect which can be used to evaluate the active earth thrust on walls of any height. A series of charts with values of the coefficients of active earth pressure with seepage calculated for selected values of the soil internal friction angle, the wall–soil friction angle, and the wall face inclination is presented.

scholarly journals Experimental Study on the Variation Law of Excess Pore Water Pressure at the Bottom of the Foundation Pit for Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qizhi Hu ◽  
Qiang Zou ◽  
Zhigang Ding ◽  
Zhaodong Xu
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Confining Pressure ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Excess Pore Water Pressure ◽  
Accurate Expression ◽  
Excess Pore

The excavation unloading of deep foundation pits in soft soil areas often produces negative excess pore water pressure. The rebound deformation of soil on the excavation surface of the foundation pit can be predicted reliably through the accurate expression of relevant variation laws. In combination with the principle of effective stress and the general equation of unidirectional seepage consolidation, an equation for calculating the rebound deformation from the bottom in the process of foundation pit excavation unloading was obtained. Additionally, a triaxial unloading test was adopted to simulate the excavation unloading processes for actual foundation pit engineering. After studying the variation law of the excess pore water pressure generated by excavation unloading, it was found that the negative excess pore water pressure increased with increasing unloading rate, while the corresponding peak value decreased with increasing confining pressure. The equation for rebound calculation was verified through a comparison with relevant measured data from actual engineering. Therefore, it is considered that the equation can reliably describe the rebound deformation law of the base. This paper aims to guide the design and construction of deep foundation pits in soft soil areas.

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