scholarly journals SETTLEMENT EVALUATION AND BACK ANALYSIS OF THE GROUND DESIGN PARAMETERS ON THE SOIL IMPROVEMENT OF PRELOADING METHOD COMBINED WITH PVD

2019 ◽  
Vol 3 (2) ◽  
pp. 179
Author(s):  
Intan Kamila Adiba ◽  
Januar Fery Irawan ◽  
Luthfi Amri Wicaksono

The use of the preloading method, which combined with PVD, is now a common method of soil improvement that proved effective in increasing bearing capacity and reducing settlement on soft soil ground types like former rice fields. In order to reach an optimum effectiveness of soil improvement, an evaluation of the settlement should be done by reviewing the performance of soil improvement along with geotechnical instruments installed in the field. In this study, the back analysis method is used to determine the soil design parameters that are following the actual conditions in the field. The results obtained from the evaluation of settlement conducted is the difference between settlement calculation theoretically before the improvement of soil with the available field data of monitoring Settlement Plate. An average percentage of 118% was obtained from the calculation. In contrast, an average percentage of 2.87% was obtained as the difference between the final settlement prediction of Asaoka's with actual settlements based on Settlement Plate readings data in the field. The parameters of the soil results from the back analysis gave new values with each of the average of Ch= 0.02936; Cc= 0.27313; kv= 0.00005 m/day; and mv= 0.00064m2/kN. The difference between theoretical settlement recalculated using the soil parameter of the back analysis method with the actual settlement based on monitoring of Settlement Plate gave an average percentage of 12.66%. Metode Preloading yang dikombinasikan dengan PVD merupakan salah satu metode perbaikan tanah yang terbukti efektif dalam meningkatkan daya dukung tanah dan mengurangi settlement pada tanah jenis lunak seperti tanah bekas sawah. Agar perbaikan tanah yang dilakukan memiliki efektifitas optimum, perlu adanya evaluasi terhadap settlement yang terjadi dengan meninjau kinerja perbaikan tanah beserta instrumeninstrumen geoteknik yang terpasang di lapangan. Selain itu, dilakukan Metode Analisa Balik untuk mengetahui parameter desain tanah yang sesuai dengan keadaan sesungguhnya di lapangan. Hasil yang didapatkan dari evaluasi settlement yang dilakukan adalah selisih settlement secara teoritis sebelum adanya perbaikan tanah dengan settlement berdasarkan monitoring Settlement Plate di lapangan dalam persentase rata-rata sebesar 118%, sedangkan selisih antara final settlement prediksi Asaoka dengan settlement akhir berdasarkan monitoring Settlement Plate di lapangan mendapatkan persentase rata-rata sebesar 2,15%. Parameter-parameter tanah hasil dari analisa balik memiliki nilai baru dengan masing-masing rata-rata sebesar Ch= 0,02936; Cc= 0,27313; kv= 0,00005 m/hari; dan mv= 0,00064m2 /kN. Sedangkan untuk selisih antara settlement secara teoritis yang dihitung kembali menggunakan parameter tanah hasil analisa balik dengan settlement aktual berdasarkan data bacaan Settlement Plate mendapatkan persentase rata-rata sebesar 12,66%.

2020 ◽  
Vol 53 (2D) ◽  
pp. 1-18
Author(s):  
Bui Truong Son

The point foundation method is the head enlarged cement deep mixing columns with high-quality control which can be used for soft ground improvement. The article aims to present the application of this method to treat soft soil for the foundation of Samse Vina factory, Ninh Binh province. The thickness of soft soil varies from 5.4 m to 7.4 m with high compressibility and low shear strength. Thus, point foundation was used to improve this layer. The prediction methods of soil bearing capacity and the settlement on the point foundation were calculated. After the treatment of soil, the unconfined compression strength of the point foundation column was determined and the static compression test for the point foundation column was also performed. The research results show that this method can significantly reduce the settlement of shallow footing and improved the bearing capacity of the soil. The final settlement of shallow footing was smaller than 2.54 cm and the bearing capacity of soil treatment can be satisfied with the requirement of construction building. This is a successful case of the application of point foundation to improve soft soil in Vietnam.


2021 ◽  
pp. 219256822110591
Author(s):  
Paul C. McAfee ◽  
Lukas Eisermann ◽  
Kenneth Mullinix

Study Design An in vitro human cadaveric biomechanics study. Objective A proof-of-concept study to quantify whether or not differences in segmental mobility associated with spinal instability could be detected by a robotic distraction system. Methods Testing was performed in fresh human cadaveric tissue. A prototype Robotic Middle Column Distractor was attached unilaterally to the pedicles of L3-4. Distraction forces up to 150 N were applied first in the intact state, and following discectomy of L3-4. Motions were recorded by time-indexed visual and fluoroscopic images, and analyzed to measure actual motions achieved. Functions of the robot unit were monitored during the procedure and evaluated qualitatively. Results A difference of 2.5 mm in z-axis motion was detected at 150 N load between the intact and post-discectomy states. The robot coupled with the image analysis method was able to clearly detect the difference between the intact (“stable”) and post-discectomy (“unstable”) spine. Data analysis of fluoroscopic images taken during the procedure showed greater motion than perceived by the investigators from qualitative review of visual data. All monitored robot functions performed within design parameters without error. Conclusion The study demonstrates the feasibility and utility of utilizing an intraoperative robotic distractor to measure the amount of spinal mobility present at a level. This could lead to an important clinical tool for both diagnostic functions as well as operative assist functions.


2019 ◽  
Vol 3 (1) ◽  
pp. 82
Author(s):  
Aflah Baihaqi Efendi ◽  
Indra Nurtjahtjaningtyas ◽  
Luthfi Amri Wicaksono

In the construction of the Trans Sumatra Toll Road, the existing land that will be used as a foundation belongs to the soft soil category. This is because the original soil to be built by the toll road is swamps. The soil improvement method used in PPKA section 2 is Vacuum Consolidation. In this study, a geotechnical instrument evaluation was carried out using the Settlement Plate to evaluate the actual settlement, then calculate the final settlement prediction with the Asaoka and Hyperbolic observation methods. Then from the monitoring data, the prediction of the final settlement was calculated using the Asaoka and hyperbolic observation methods, calculated the value of the degree of consolidation from each method. So that the results of the calculation can be concluded in the form of the superiority of each method used as consideration for further planning. The results obtained in this study are the actual settlement with theoretical and settlement predictions along with the comparison of the two observation methods. From the average value of the degree of consolidation produced also in the percentage of 98.68% while the hyperbolic is 99.35%. The calculation of soil subsidence using the Asaoka method is more same with the field (actual). Because the data used for the Asaoka comes from all monitoring data on the field settlement plate. Pada pembangunan jalan Tol Trans Sumatra, tanah eksisting yang akan dijadikan pondasi tergolong dalam kategori tanah lunak. Hal itu dikarenkan tanah asli yang akan dibangun jalan tol merupakan rawa-rawa. Metode perbaikan tanah yang digunakan di PPKA seksi 2 adalah Vacuum Consolidation. Dalam kajian ini, dilakukan evaluasi instrumen geoteknik menggunakan Settlement Plate untuk mengevaluasi penurunan aktual, kemudian menghitung prediksi penurunan akhir (final settlement) dengan metode observasi Asaoka dan Hiperbolik. Kemudian dari data monitoring dihitung besar prediksi penurunan akhir tanah menggunakan metode observasi asaoka dan hiperbolik, dihitung nilai derajat konsolidasi dari setiap metode. Sehingga dari hasil perhitungan didapat kesimpulan berupa keunggulan setiap metode yang digunakan sebagai pertimbangan untuk perencanaan lanjutan. Hasil yang diperoleh dalam kajian ini adalah besar penurunan aktual dengan teoritis dan prediksi settlement beserta mengetahui perbandingan dari kedua metode observasi. Dari nilai rerata derajat konsolidasi yang dihasilkan juga pada asaoka sebesar 98,68% sedangkan pada hiperbolik sebesar 99,35%. Perhitungan penurunan tanah menggunakan metode asaoka lebih sesuai dengan lapangan (aktual). Dikarenakan data yang digunakan untuk asaoka berasal dari semua data monitoring settlement plate lapangan.


Author(s):  
Phan Huy Dong

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.


2013 ◽  
Vol 275-277 ◽  
pp. 1398-1402
Author(s):  
Yong Hua Cao ◽  
Chang Quan Yin

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.


2019 ◽  
Vol 5 (3) ◽  
pp. 1
Author(s):  
Erdina Tyagita Utami ◽  
Indra Noer Hamdhan ◽  
Kabul Suwitaatmadja

ABSTRAKTanah lunak merupakan tanah dengan stabilitas rendah yang dapat mengalami penurunan yang besar saat diberi beban. Preloading adalah salah satu cara memperbaiki tanah lunak tersebut. Penelitian ini bertujuan untuk mengetahui stabilitas tanah lunak akibat perbaikan tanah menggunakan preloading. Pemodelan dilakukan dengan cara menghitung kenaikan kuat geser tanah. Untuk mencari faktor keamanan dan bidang longsor dilakukan pemodelan dengan menggunakan Metode Elemen Hingga Plaxis 2D dengan pembebanan 2 tahap. Pembebanan pertama yang dilakukan adalah setinggi 5 meter dan pembebanan ke dua yaitu setinggi 1-2 meter. Jarak perbaikan tanah juga dimodelkan dalam penelitian ini sejauh 5 meter, 10 meter, dan 15 meter dari sisi lokasi  timbunan batu bara. Batasan faktor keamanan (SF) minimum terhadap keruntuhan adalah 1,5. Perbaikan tanah dengan metode preloading menyebabkan tanah akan memampat dan dapat stabil dalam menerima beban.Kata kunci: tanah lunak, stabilitas tanah, preloading, faktor keamanan, metode elemen hingga ABSTRACTSoft soils are soils with low stability which can experience a large settlement under loading process. Preloading is one of the ways to improve the soft soil. This study aims to determine the stability of soft soils due to soil improvement using preloading. Modeling is done by calculating the increase in soil shear. To find the safety factor and the landslide field, modeling is done using Finite Element Method 2D Plaxis by two stages of loading. The first loading is 5 meters high and the second loading is 1-2 meters. Ground improvement distances are also modeled in this study as far as 5 meters, 10 meters and 15 meters from the side of the location of the coal emankment. The minimum safety factor (SF) limit to collapse is 1.5. Improvement of the soil using the preloading method causes the soil to compress and can be stable in receiving loads.Keywords: soft soil, soil stability, preloading, safety factor, finite elemen method


2020 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Nurlaila Suci Rahayu Rais ◽  
Dedeh Apriyani ◽  
Gito Gardjito

Monitoring of warehouse inventory data processing is an important thing for companies. PT Talaga mulya indah is still manual using paper media, causing problems that have an effect on existing information, namely: problems with data processing of incoming and outgoing goods. And the difference between data on the amount of stock of goods available with physical data, often occurs inputting data more than once for the same item, searching for available data, and making reports so that it impedes companies in monitoring inventory of existing stock of goods. Which aims to create a system that can provide updated information to facilitate the warehouse admin in making inventory reports, and reduce errors in input by means of integrated control. In this study, the authors used the data collection method used in this analysis using the method of observation, interviews, and literature review (literature study). For analysis using the PIECES analysis method. Furthermore, the system design used is UML (Unified Modeling Language). The results of this study are expected to produce the right data in the process of monitoring inventory data processing, also can provide the right information and make it easier to control the overall availability of goods.


Manuskripta ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Novarina Novarina

Abstract: This research is a comparative literary study that uses Malay and Javanese versions of Mahabarata text sources. The research objects used were the text edition of Pandhawa Gubah (PG) by Sudibjo Z. Hadisutjipto and the text of Cheritera Pandawa Lima (CPL) by Khalid Hussain. The research method used is descriptive-analysis method. In the comparative study used a comparative literary theory proposed by Endraswara (2011). The results of the text comparison reveal the similarities and differences in the image of Bima figures in the Javanese and Malay versions. The equation as a whole is that both texts contain the same heroic storyline and heroic character, Bima. In addition, Indian influence is still evident in the two texts seen from the nuances of Hinduism that exist in both texts. While the difference is seen in the events that accompany Bima's struggle in achieving his victory. Based on these similarities and differences, it can be seen that the authors attempt to represent the concept of metaphysical interactions vertically and horizontally expressed through PG text. --- Abstrak: Penelitian ini adalah satu kajian sastra bandingan yang menggunakan sumber teks Mahabarata versi Melayu dan Jawa. Objek penelitian yang digunakan adalah edisi teks Pandhawa Gubah (PG) karya Sudibjo Z. Hadisutjipto dan teks Cheritera Pandawa Lima (CPL) karya Khalid Hussain. Metode penelitian yang digunakan adalah metode deskriptif-analisis. Dalam telaah perbandingan digunakan teori sastra bandingan yang dikemukakan Endraswara (2011). Hasil perbandingan teks mengungkapkan adanya persamaan dan perbedaan citra tokoh Bima dalam versi Jawa maupun versi Melayu. Persamaan secara keseluruhan adalah kedua teks tersebut mengandung alur cerita kepahlawanan dan tokoh pahlawan yang sama yaitu Bima. Selain itu, pengaruh India masih tampak dalam kedua teks tersebut dilihat dari nuansa Hinduisme yang ada dalam kedua teks. Sementara perbedaannya tampak pada peristiwa-peristiwa yang menyertai perjuangan Bima dalam mencapai kemenangannya. Berdasarkan persamaan dan perbedaan tersebut tampak adanya upaya penulis untuk merepresentasikan konsep interaksi metafisik secara vertikal dan horizontal yang diungkapkan melalui teks PG.


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