scholarly journals PLANNING OF SOFT SOIL IMPROVEMENT WITH PRELOADING AND PREFABRICATED VERTICAL DRAIN METHOD

2018 ◽  
Vol 2 (01) ◽  
pp. 19
Author(s):  
Ana Crosita Ningsih ◽  
Luthfi Amri Wicaksono ◽  
Mokhamad Farid Ma'ruf
Keyword(s):  
Urban Areas ◽  
Soil Structure ◽  
Soft Soil ◽  
Soil Improvement ◽  
Building Site ◽  
Planning Time ◽  
Coral Sand ◽  
Rapid Construction ◽  
Prefabricated Vertical Drain ◽  
Surrounding Areas

The northern coastal areas of Java such as Gresik and surrounding areas have a soil structure of alluvium consisting of gravel / coral, sand, clay soil and shells. Soil basic conditions are soft enough to cause land subsidence (settlement). The need for rapid construction causes the urban areas to become less and more for development land. This requires the improvement of soft soil to be used as a building site. As for the method to be done in this planning using a combination of preloading and PVD methods to accelerate the process of land degradation. Based on the planning result, the total height of embankment (preloading) is 3.5 m and the planning time lasted 4 months. Soft soil improvement is done up to 25 m depth with PVD design using triangle pattern and space 1.3 m. The 95% consolidation decrease due to the load of embankment caused the soil to fall as deep as 1,928 m. In this planning use modeling Plaxis 8.6 2D and the resulting yield of soil is 1,990 m. Wilayah pesisir pantai utara Jawa seperti daerah Gresik dan sekitarnya mempunyai struktur tanah berupa alluvium yang terdiri dari batu kerikil/koral, pasir, tanah lempung dan pecahan kulit kerang. Kondisi tanah dasar yang cukup lunak menyebabkan terjadinya penurunan tanah (settlement). Adanya kebutuhan konstruksi yang semakin pesat menyebabkan wilayah perkotaan menjadi semakin sedikit untuk dijadikan lahan pembangunan. Hal ini mengharuskan dilakukannya upaya perbaikan tanah lunak agar bisa dijadikan lahan bangunan nantinya. Adapun pada metode yang akan dilakukan pada perencanaan ini menggunakan kombinasi metode preloading dan PVD untuk mempercepat proses penurunan tanah. Berdasarkan hasil perencanaan didapatkan total tinggi timbunan (preloading) adalah 3,5 m dan waktu perencanaan berlangsung 4 bulan. Perbaikan tanah lunak dilakukan sampai dengan kedalaman 25 m dengan desain PVD menggunakan pola segitiga dan spasi 1,3 m. Penurunan konsolidasi 95% akibat beban timbunan menyebabkan tanah turun sedalam 1,928 m. Pada perencanaan ini menggunakan pemodelan Plaxis 8.6 2D dan hasil penurunan tanah yang dihasilkan adalah sedalam 1,990 m.

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).

Influence of Bagasse Ash as Partial Replacement of Cement on Soft Soil Improvement

2017 ◽  
Vol 728 ◽  
pp. 373-378
Author(s):  
Hatairat Poorahong ◽  
Naphol Yoobanpot
Keyword(s):  
Electron Microscopy ◽  
Soil Structure ◽  
Soft Soil ◽  
Dry Weight ◽  
Soil Improvement ◽  
Soil Strength ◽  
Partial Replacement ◽  
Hydration Reaction ◽  
Stabilized Soil ◽  
Scanning Electron

Compressive strength of soft soil improvement using cement only and cement partial replacement with bagasse ash were studied. The strength characteristic of stabilized soil was investigated with various curing times of 7, 14 and 28 days. Tested result reveal the stabilized soil strength have trend to increase with time. Using 20% of bagasse ash by dry weight was suggested as optimum content for cement replacement to obtain highest strength. Comparing with cement improved soil, the stabilized soil strength of 20% BA replacement had higher over 25% and modulus of elasticity (E50) was increased up to 37% at 28 days of curing. Change on stabilized soil structure was observed by scanning electron microscopy (SEM) reveal that the formation of hydration reaction product, CSH fabric and rod-like ettringite, have transformed stabilized soil structure denser and harder consequence increase in soil strength with time.

scholarly journals Method of removing secondary compression on clay using preloading

2018 ◽  
Vol 195 ◽  
pp. 03006
Author(s):  
Ega Dhianty ◽  
Indrasurya B. Mochtar
Keyword(s):  
Void Ratio ◽  
Soft Soil ◽  
Soil Improvement ◽  
Compression Index ◽  
Secondary Compression ◽  
Initial Void Ratio ◽  
Prefabricated Vertical Drain ◽  
Primary Consolidation ◽  
Short Time ◽  
External Loads

Due to external loads, the soft soil will undergo a large compression of both primary and secondary compression. With soil improvement using prefabricated vertical drain (PVD), the time of primary compression becomes shorter so that secondary compression occurs in short time. There has been little research on how to remove secondary compression. Therefore, further investigation of behaviour and method of removing secondary compression is necessary. This research was conducted based on an experimental study of clay consolidation test with a variation of loading time in the laboratory. The results show that there is an empirical correlation among the secondary compression index (Cα’), the initial void ratio (e0), the void ratio at the end of primary consolidation (ep), and the effective consolidation stress (P’). The correlations obtained from this study are Cα’ = (0.0072e0 - 0.0067)P’ and Cα’ = (0.0077ep - 0.006)P’. The greater the effective consolidation stress is, the greater the secondary compression index will become. Therefore, in soil improvement secondary compression can be removed by giving an extra load (Δq) that causes additional compression to the primary consolidation where the magnitude equals to the expected secondary compression. Then, this Δq could be removed at the end of the primary consolidation.

scholarly journals Methods for mitigating effects induced by tunnelling on nearby existing buildings in cities

2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 57-65
Author(s):  
Ngan Minh Vu ◽  
Luyen Van Nguyen ◽  
Lam Phuc Dao ◽  
Keyword(s):  
Urban Areas ◽  
Soft Soil ◽  
Soil Improvement ◽  
Soil Conditions ◽  
Existing Buildings ◽  
Tunnel Design ◽  
Negative Impacts

Tunnelling in urban areas in soft soil conditions has risks of negative impacts on nearby existing buildings. When buildings are in/on influence zones induced by tunnelling, they can be damaged in the case of without any mitigating methods applied. This paper summarizes and presents a three category classification of mitigating effects induced by tunneling including methods in tunnel design and tunnelling process, and soil improvement methods, as well as reinforcement for buildings. On the basis of the study, designers and engineers can obtain suitable solutions for their safe tunnel projects.

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 Influence of vertical drains on improving dredged mud by vacuum consolidation method

2018 ◽  
Vol 12 (5) ◽  
pp. 63-72
Author(s):  
Phan Huy Dong
Keyword(s):  
Soft Soil ◽  
Drainage System ◽  
Soil Improvement ◽  
Vacuum Consolidation ◽  
Vertical Drains ◽  
Fine Grained ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Reclamation Area ◽  
Preloading Method

Vacuum consolidation preloading method (VCM) has been widely adopted as an effective solution for soft soil improvement over the world. Recently, VCM has been successfully applied for improving the geotechnical properties of dredged mud, which is normally dumped at reclamation area by hydraulic pumping. However, it has been also reported that application of VCM for treatment of the dredged mud has been failed in some particular cases. The failures are mainly caused by clogging problem in vertical drains due to fine-grained soils that reduces the drainage efficiency of drainage system. To address this issue, a series of model tests have been conducted to investigate the performances of vertical drains among prefabricated vertical drain, sand drain and filter pipe. As the goal, the performances of types of the vertical drain solutions are analyzed based on the monitoring data of settlement, influencing zone surrounding the vertical drains. The test results reveal that sand drain shows the best performance among the others. In addition, the clogging problem is clearly shown in case of PVD. Keywords: dredging slurry; vacuum consolidation method; model test; PVD; filter pipe; sand drain.

scholarly journals ALTERNATIVE IMPROVEMENT OF SUBGRADE AND REINFORCEMENT OF EMBANKMENT ON PELABUHAN KUALA TANJUNG TOLL ROAD, INDERAPURA - KUALA TANJUNG SECTION IN NORTH SUMATRA (STA 0+000 S/D STA 3+500)

CERUCUK ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Agung Wahyu Eka Prasetya ◽  
Hutagamissufardal Hutagamissufardal
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Soil Improvement ◽  
Stability Control ◽  
Computer Assisted ◽  
Toll Road ◽  
Loading Method ◽  
Compression Time ◽  
Prefabricated Vertical Drain ◽  
North Sumatra

Planning the Kuala Tanjung Ruas Port of Inderapura - Kuala Tanjung Toll Road is one of the efforts to support economic growth in North Sumatra. The toll road will be built on a pile with a height of 2 ms / 9 m at STA 0 + 000 to STA 3 + 500. Due to limited land, the toll road section must be built on the poor subgrade. Based on the N-SPT test results, it is known that the subsoil consists of a clay layer with a thickness reaching 36 meters and a layer of sand at the top and bottom with a low N-SPT value. If the soft subgrade is burdened with a high heap, it is estimated that the subgrade will experience landslides, so it is necessary to plan the improvement of the subgrade and reinforcement of the pile.The soil improvement method chosen is the pre-loading method with a combination of the prefabricated vertical drain (PVD). Pre-loading method aims to spend the compression that occurs on the subgrade so that there is no compression during the service life of the road. The combination with PVD is intended to speed up the compression time in thick clay layers. The stability of the embankment will be calculated using a computer-assisted program, and geotextile reinforcement planning will be carried out if the value of the safety factor does not meet the requirements.Based on the analysis of compression computation will be divided into five zones. The amount of compression obtained under various piles of 2 ms / d 9 m was 2.25 m, 1.49 m, 1.75 m, 2.57 m, 3.65 m, 4.3 m, 4.69 m, and 5.06 m with an initial heap height of 5.02 m, 5.26 m, 6.51 m, 8.34 m, 10.41 m, 12.07 m, 13.46 m, and 14.83 m. Compression time required for subgrade is relatively long with a period of more than five years so that the planned acceleration with PVD. To accelerate the compression time to 5-6 weeks, a triangular PVD installation pattern is used with a spacing between PVD of 1.5 m and a depth of PVD installation as thick as a soft soil layer. From the results of the pile stability control, it is predicted that the pile will experience slides so that the reinforcement is installed with geotextile.Rp1.598,213,522,582.08.

scholarly journals Study of VCM Improved Soft Soil Properties Using Non-Destructive and Destructive Techniques

Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 300
Author(s):  
Diandri Fakhri Alditra ◽  
Susit Chaiprakaikeow ◽  
Suttisak Soralump
Keyword(s):  
Soil Properties ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Soft Soil ◽  
Soil Improvement ◽  
Prefabricated Vertical Drain ◽  
Soil Settlement ◽  
Pump Pressure ◽  
Non Destructive

In Bangkok, the demand for housing is extensively high due to the city growing rapidly, so some swampy areas are filled with soil. A Prefabricated Vertical Drain (PVD) with the Vacuum Consolidation Method (VCM) is required to make the soil applicable for construction. However, it is difficult to monitor the soil strength during the process because the airtight sheet will be broken. This research aims to study the possibility of using the Spectral Analysis of Surface Waves (SASW) test to monitor the effectiveness of the VCM method and to study the development of shear-wave velocity over the consolidation period. Multiple instruments were installed on site, namely, vacuum gauges, settlement plates, and a piezometer, as well as a borehole to monitor the pump pressure, settlement, porewater pressure, and soil properties. Ten SASW tests were taken to measure the change in shear-wave velocity (Vs) over 7 months. The results showed an increment in the Vs along with increments in the settlement and undrained shear strength (Su), as well as a decrement in pore pressure during the consolidation period. The correlation between Vs and soil settlement was developed to predict the amount of settlement using Vs. These all indicated the potential of using the SASW method for soil improvement monitoring purposes.

International Institutions and the Environmental Crisis: A Look Ahead

1972 ◽  
Vol 26 (2) ◽  
pp. 469-478 ◽  
Author(s):  
David A. Kay ◽  
Eugene B. Skolnikoff
Keyword(s):  
Urban Areas ◽  
International Institutions ◽  
Modern Technology ◽  
Environmental Crisis ◽  
Widespread Application ◽  
Human Environment ◽  
Look Ahead ◽  
International Issue ◽  
Surrounding Areas

In the industrialized northern hemisphere we are assaulted daily with evidence of the deteriorating quality of the human environment: Rivers are closed to fishing because of dangerous levels of contamination; the safety of important foods is challenged; the foul air that major urban areas have been forced to endure is now spreading like an inkblot into surrounding areas. Lack of early concern about the implications for the environment of the widespread application of modern technology has allowed the problem to grow rapidly into a critical domestic and international issue.

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