scholarly journals ANALISIS TIANG PANCANG SEBAGAI DINDING PENAHAN TANAH DENGAN MENGGUNAKAN PROGRAM METODE ELEMEN HINGGA

2020 ◽  
Vol 3 (3) ◽  
pp. 889
Author(s):  
Hans Wilsen Cahyadinata ◽  
Chaidir Anwar Makarim
Keyword(s):  
Groundwater Level ◽  
River Flow ◽  
Retaining Wall ◽  
Maximum Deflection ◽  
Construction Site ◽  
Flow Area ◽  
Concrete Piles ◽  
Coulomb Model ◽  
Soil Instability ◽  
Soil Excavation

In recent years the number of  infrastructure construction in Indonesia is surging. Sometimes soil excavation and filling at the construction site needed to be done. Disturbtion of soil may cause soil instability at the site so in order to prevent it from collapsing constructing a retaining wall is one  possible solution like constructing a retaining wall from concrete piles on river flow area to replace the old soil retaining wall that broke down. Rainfall is simulated by staging the rise of both groundwater and river surface level. The concrete piles used have dimension of 400x400 mm and 0,8 m between each pile and topped of with capping beam 0,8 m wide and 0,5 m thick. Calculation is done by program for deflection and moment of pile with Mohr-Coulomb model. Deflection and moment of pile when groundwater level is at -6 meter is 2,376 cm and 115,40 kNm, then 4,245 cm and 199,95 kNm when groundwater level reaches ±0 meter. The results will then be compared  agaisnt maximum deflection and moment allowed for the pile. After analysis is done it is found that both deflection and moment experienced a greater jump in value when groundwater level is nearing top of pile. AbstrakBeberapa tahun belakangan banyak pembangunan yang berjalan di Indonesia. Namun terkadang kontur tanah pada lokasi pembangunan kurang sesuai dengan kebutuhan desain sehingga dilakukan penggalian atau pengurugan. Pengubahan kontur tanah dapat menyebabkan ketidakstabilan pada tanah di lokasi sehingga salah satu solusi untuk mencegah terjadinya longsor pada tanah adalah dengan membuat dinding penahan tanah. Salah satu hal yang menarik adalah pembangunan dinding penahan tanah dari tiang pancang beton di daerah aliran sungai untuk menggantikan dinding penahan tanah lama yang rusak. Perhitungan akan mensimulasikan terjadinya hujan sehingga terjadi peningkatan muka air tanah dan permukaan sungai secara bertahap. Tiang yang digunakan pada pemodelan memiliki ukuran 400x400 mm dengan jarak antar tiang 0,8 meter yang dihubungkan oleh capping beam selebar 0,8 meter dan tebal 0,5 meter. Perhitungan dilakukan dengan program untuk mencari defleksi dan momen pada tiang pada pemodelan Mohr-Coulomb. Defleksi dan momen yang terjadi pada tiang saat muka air tanah -6 meter sebesar 2,376 cm dan 115,40 kNm, kemudian saat ±0 meter sebesar 4,245 cm dan 199,95 kNm. Hasil defleksi dan momen kemudian dibandingkan terhadap syarat batas yang sudah ditentukan sebelumnya. Setelah analisis dilakukan ditemukan bahwa kenaikan defleksi dan momen paling besar terjadi pada tahap dimana air naik mendekati puncak tiang.

scholarly journals ANALYTICAL AND NUMERICAL METHODS FOR DETERMINING THE CARRYING CAPACITY OF A PILE BARETT ON WEAK SOILS IN DEEP PITS

2021 ◽  
Vol 17 (3) ◽  
pp. 94-101
Author(s):  
Rashid Mangushev ◽  
Nadezhda Nikitina ◽  
Hieu Le Trung ◽  
Ivan Tereshchenko
Keyword(s):  
Bearing Capacity ◽  
Numerical Test ◽  
Full Scale ◽  
Construction Site ◽  
Weak Soils ◽  
Geological Conditions ◽  
Full Scale Tests ◽  
Soil Excavation ◽  
Deep Pits ◽  
The City

The article provides an analysis of the bearing capacity of barrett piles in difficult geological conditions at a construction site in the city of Hanoi, Vietnam based on the results of analytical calculations according to Russian building codes, mathematical modeling and field full-scale tests. The paper describes a numerical test of a single barrette for Mohr-Coulomb and Hardening Soil models in the Midas GTS NX software package. The bearing capacity of a barrette in soft soils is also proposed to be determined by an analytical solution for calculating the settlement of a single pile, taking into account the unloading of the pit after soil excavation. The results of full-scale tests at the site of future construction, graphs of "load-settlement" of the barrette head from the applied vertical load and the general assessment of the bearing capacity of the barret pile by various methods are shown.

The research of Meinong earthquake induced hydrological anomalies and increased vertical permeability in southwestern Taiwan

2020 ◽  
Author(s):  
Yan-Yao Lin ◽  
Shih-Jung Wang ◽  
Wen-Chi Lai
Keyword(s):  
Groundwater Level ◽  
River Flow ◽  
Large River ◽  
Shallow Aquifer ◽  
Deep Aquifer ◽  
Tidal Analysis ◽  
Level Change ◽  
Vertical Permeability ◽  
Hydrogeological Characteristics ◽  
Groundwater Level Change

<p>Hydrological anomalies induced by the earthquakes are valuable research data to understand the hydrogeology structure. At the same time, a complete hydrogeological data is the key to the study of earthquake hydrology. In this research, we collected the anomalous hydrological data after the M<sub>w</sub> 6.4 2016 Meinong Earthquake in Taiwan. The main purpose is to know the mechanism of hydrological changes triggered by earthquake and understand the local hydrogeological characteristics in the southern Taiwan.</p><p>From the distribution of the groundwater level change in the same location but different depths of aquifer, as well as the location of the rupture and liquefaction, it could be found that the co-seismic groundwater level change is large in Chianan Plain in the northwest of the epicenter and accompanied with a lot of ruptures and liquefactions located along the Hsinhua Fault. However, the observations in several wells around the Hsinhua Fault show a different water level change pattern compared with the other wells in Chianan Plain. Actually, these wells show that the co-seismic groundwater level decreases in the deep aquifer and increase in the shallow aquifer. It is shown that the Meinong Earthquake may enhance the connectivity between different aquifers near the fault zone and produce an increased vertical pressure gradient. The anomalous hydrological phenomenon also reflected in the river flow. Based on the river flow data we collected from five stations in the Zengwun River watershed, the river flow at two stations in the upstream dose not change after earthquake. There is a little increase at the midstream station. However, a large river flow increase is observed at the downstream station. After excluding the influence of rainfall, we think that the large amount of anomalous flow is caused by the rise of the co-seismic groundwater level between the middle and downstream sections, and a large amount of liquefaction in this area can prove this hypothesis.</p><p>The hypothesis of connectivity changes between different aquifers can be verified by analyzing the tidal response of different aquifers. Many studies have used the tide analysis to obtain the aquifer permeability and compressibility, and compared the changes in the analysis results before and after the earthquake. We think that if different aquifers are vertically connected after earthquake, the tidal analysis results should show a consistent permeability. Tidal analysis is executing now and the results will be provided at conference.</p>

scholarly journals River Flow Monitoring by Sentinel-3 OLCI and MODIS: Comparison and Combination

2020 ◽  
Vol 12 (23) ◽  
pp. 3867
Author(s):  
Angelica Tarpanelli ◽  
Filippo Iodice ◽  
Luca Brocca ◽  
Marco Restano ◽  
Jérôme Benveniste
Keyword(s):  
Time Series ◽  
Flow Velocity ◽  
Near Infrared ◽  
River Flow ◽  
Quality Data ◽  
Mean Flow ◽  
Po River ◽  
Flow Area ◽  
Flow Monitoring ◽  
Mean Flow Velocity

The monitoring of rivers by satellite is an up-to-date subject in hydrological studies as confirmed by the interest of space agencies to finance specific missions that respond to the quantification of surface water flows. We address the problem by using multi-spectral sensors, in the near-infrared (NIR) band, correlating the reflectance ratio between a dry and a wet pixel extracted from a time series of images, the C/M ratio, with five river flow-related variables: water level, river discharge, flow area, mean flow velocity and surface width. The innovative aspect of this study is the use of the Ocean and Land Colour Instrument (OLCI) on board Sentinel-3 satellites, compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) used in previous studies. Our results show that the C/M ratio from OLCI and MODIS is more correlated with the mean flow velocity than with other variables. To improve the number of observations, OLCI and MODIS products are combined into multi-mission time series. The integration provides good quality data at around daily resolution, appropriate for the analysis of the Po River investigated in this study. Finally, the combination of only MODIS products outperforms the other configurations with a frequency slightly lower (~1.8 days).

scholarly journals Multi-annual droughts in the English Lowlands: a review of their characteristics and climate drivers in the winter half-year

2015 ◽  
Vol 19 (5) ◽  
pp. 2353-2375 ◽  
Author(s):  
C. K. Folland ◽  
J. Hannaford ◽  
J. P. Bloomfield ◽  
M. Kendon ◽  
C. Svensson ◽  
...  
Keyword(s):  
Groundwater Level ◽  
River Flow ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Standardized Precipitation Index ◽  
Early Warning Systems ◽  
Weak Links ◽  
Future Research ◽  
Quasi Biennial Oscillation ◽  
Winter Half

Abstract. The English Lowlands is a relatively dry, densely populated region in the south-east of the UK in which water is used intensively. Consequently, parts of the region are water-stressed and face growing water resource pressures. The region is heavily dependent on groundwater and particularly vulnerable to long, multi-annual droughts primarily associated with dry winters. Despite this vulnerability, the atmospheric drivers of multi-annual droughts in the region are poorly understood, an obstacle to developing appropriate drought management strategies, including monitoring and early warning systems. To advance our understanding, we assess known key climate drivers in the winter half-year (October–March) and their likely relationships with multi-annual droughts in the region. We characterise historic multi-annual drought episodes back to 1910 for the English Lowlands using various meteorological and hydrological data sets. Multi-annual droughts are identified using a gridded precipitation series for the entire region, and refined using the Standardized Precipitation Index (SPI), Standardized Streamflow Index (SSI) and Standardized Groundwater level Index (SGI) applied to regional-scale river flow and groundwater time series. We explore linkages between a range of potential climatic driving factors and precipitation, river flow and groundwater level indicators in the English Lowlands for the winter half-year. The drivers or forcings include El Niño–Southern Oscillation (ENSO), the North Atlantic tripole sea surface temperature (SST) pattern, the Quasi-Biennial Oscillation (QBO), solar and volcanic forcing and the Atlantic Multi-decadal Oscillation (AMO). As expected, no single driver convincingly explains the occurrence of any multi-annual drought in the historical record. However, we demonstrate, for the first time, an association between La Niña episodes and winter rainfall deficits in some major multi-annual drought episodes in the English Lowlands. We also show significant (albeit relatively weak) links between ENSO and drought indicators applied to river flow and groundwater levels. We also show that some of the other drivers listed above are likely to influence English Lowlands rainfall. We conclude by signposting a direction for this future research effort.

Perencanaan Teknik Penanggulangan Kelongsoran Dengan Menggunakan Konstruksi Retaining Wall (Studi Kasus Jalan Tanjung Selor – Tana Tidung)

2018 ◽  
Vol 2 (2) ◽  
pp. 105
Author(s):  
Hasrullah Hasrullah
Keyword(s):  
Retaining Wall ◽  
Mountainous Areas ◽  
Land Area ◽  
High Rainfall ◽  
Road Users ◽  
Soil Instability

Given the contours of the island of Borneo are numerous plateaus, allowing roads to be constructed in mountainous areas or hilly, it can be seen on the streets shaft North Kalimantan namely Tanjung Selor – Tana Tidung road on the path Tanjung Selor – Tana Tidung road there is a level of steepness high whitout made retaining wall can be causing landslides that could be dangerous for road users and surrounding residents. This can occur as a result of soil instability especially when coupled with high rainfall, It is necessary to retaining that handy to withstand the preassures in the soil so that the soil does not move and headed towards the bottom. With the development of science, the more ways you can use to avoid or rectify the land / area avalanche of one of them by making a retaining wall.

Application Of Fuzzy Logic In The Assessment Of River Flow Characteristics At The Pier Scour

2012 ◽  
Author(s):  
Ponselvi Jeevaragagam ◽  
Ahmad Khairi ◽  
Tahir Ahmad
Keyword(s):  
Fuzzy Logic ◽  
River Flow ◽  
Flow Characteristics ◽  
Uncertainty Modeling ◽  
Bridge Scour ◽  
Flow Area ◽  
Pier Scour ◽  
Bridge Model ◽  
Prevention Method ◽  
Fuzzy Logic Technique

Pada masa kini, tiada pembangunan teknik yang rasional untuk seseorang jurutera jambatan mengikutinya sebagai panduan apabila menilai kesan kerokan disebabkan aliran sungai pada penapak tiang jambatan. Biasanya penilaian kerokan pada jambatan adalah berdasarkan prosedur subjektif yang mana kosnya adalah mahal, pengambilan masa, ketidakpastian dan mempunyai bias oleh seseorang individu. Oleh itu, tujuan penyelidikan ini adalah untuk memperkenalkan teknik logik kabur dalam menilai sifat-sifat aliran sungai pada hulu jambatan (keadalaman aliran (Y1); kadaralir (Q1); kelajuan (V1); dan luas aliran (A1)), yang mana menyebabkan kerokan pada penapak tiang jambatan. Dalam mencapai objektif kajian ini, satu contoh masalah telah diperkenalkan untuk menggambarkan penggunaan metodologi terhadap hipotesis model jambatan yang merentangi Sungai Cherul di Ban Ho, Terengganu, Malaysia. Daripada penyelidikan ini, tahap keadaan kerokan pada penapak tiang boleh ditentukan dan maklumat ini dapat digunakan kelak oleh seseorang jurutera jambatan dalam menyediakan kaedah kawalan yang sesuai. Seterusnya, kaedah ini boleh membantu jurutera jambatan untuk membuat keputusan yang lebih rasional semasa menjalankan program pembaikan jambatan berdasarkan data pengawasan jambatan. Kata kunci: Penilaian kerokan jambatan; keadaan kerokan tiang jambatan; kesan aliran sungai; model kata putus seragam; permodelan ketidakpastian Currently; there is no well-established technique for a bridge inspector to follow when assessing the river flow effect to the scour depth at a bridge pier. The assessment of a bridge scour is normally based on subjective procedures that are costly, time consuming, uncertain and has a personal bias. Therefore, the purpose of this research is to propose the fuzzy logic technique in assessing the river flow characteristics at the upstream of the bridge (flow depth (Y1); discharge (Q1); velocity (V1); and flow area (A1)), which are resulted scouring at the pier foundation. In order to achieve the objective of this research, an example problem is presented to illustrate the use of the proposed methodology on a hypothetical bridge model across Cherul River at Ban Ho, Terengganu, Malaysia. From the research, the severity of scour condition at the pier foundation can be determined and this information will be useful for a bridge engineer to provide the relevant countermeasure or prevention method. Finally; this approach can assist a bridge engineer in making a rational decision for carrying out the bridge maintenance programme based on data taken from regular bridge inspection Key words: Bridge scour assessment; pier scour condition; river flow effects; uniform decision-making model; uncertainty modeling

Triaxial Compressive Behavior of Two Types of Concrete with Curing Conditions of Construction Site

2011 ◽  
Vol 261-263 ◽  
pp. 38-42
Author(s):  
Yi Bo Xiong ◽  
Lu Peng ◽  
Jin Xu ◽  
Liang Ma
Keyword(s):  
Failure Criterion ◽  
Raw Materials ◽  
Triaxial Compression ◽  
Experimental Program ◽  
Construction Site ◽  
Curing Conditions ◽  
Different Types ◽  
Confining Pressures ◽  
Coulomb Model ◽  
Exponential Decay Law

Based on an extensive experimental program under uniaxial and triaxial compression, this paper studies the mechanical behavior of two types of concrete with the same raw materials and the same curing conditions of the construction site. Stress-strain relations and strengths are obtained under triaxial compression with confining pressures from 10MPa to 120MPa. Material constants of different types of failure criterion are determined by the statistical method with the data from this study and public literature, including linear Mohr-Coulomb model, parabolic Willam-Warnke failure criterion and power functional Johnson-Holmquist model. The results indicate that the modulus of both types of concrete decrease as an exponential decay law with the increase of confining pressures in triaxial compression.

scholarly journals KUALITAS AIR SUNGAI SAGO KECAMATAN SENAPELAN KOTA PEKANBARU TAHUN 2016

2020 ◽  
Vol 8 (2) ◽  
pp. 138-147
Author(s):  
Jufenti Ade Fitri
Keyword(s):  
Water Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Design Research ◽  
River Flow ◽  
Flow Area ◽  
Common Purpose ◽  
Residential Market ◽  
The City

River sago that is a tributary siak which has received pressures environment a result of of land use and activities people of residential , market , office , the hospital and industry .Pressure that environment indicated has caused a decline in the quality of the waters of the sago. A common purpose research is to know the quality of the waters of the sago kecamatan senapelan the city of pekanbaru 2016 and factors that affects the quality of the waters of the sago kecamatan senapelan the city of pekanbaru. This research is descriptive quantitative with the design research non standard, to know the quality of the waters of the based on an indicator water quality. Samples to be taken from 3 points, station I in the upstream location jl. Cut Nyak Dien gg. Jambu Air, station II in central location jl. Juanda, station III downstream jl. Pelita Pantai The result of this research that is explained that the quality of the waters of the sago in station I in the upstream is category and he medium, with the Water Quality Index in the morning that is 66.09 and afternoon 65.33.Station II in the middle is category and he medium with the Water Quality Index in the morning that is 61.05 and afternoon 56.34. Station III downstream is of medium category medium with the water quality index in the morning that is 65.45 and afternoon 57.88. Conclusion in this research is activity the community a watershed Sago will affect the quality of the waters of the Sago. Advice in this research was significance social expected the formulation of local regulations the city of Pekanbaru about absorption wells. Significance scientific research a kind of to be done sampling repeated based on different time.   Keywords : Water Quality Index (WQI), River, River Flow Area (DAS)

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