Effect of Installation Depths and Emitter Spacing on Water Productivity and Yield of a Subsurface Drip Irrigated Sugarcane

In the present investigation the effect of drip lateral installation depths and emitter spacing on sugarcane crop water productivity and yield was studied by installing laterals at 15, 20 and 30 cm depths from surface, while the emitters were spaced at 50, 60 and 75 cm. A factorial experiment in the form of randomized complete block design was carried out at the Sugarcane Research and Training Institute of Khuzestan in South-West of Iran. Sugarcane quantity specifications results showed there was significant difference between treatments in terms of drip emitter spacing and lateral installation depths and their interactions at 1% probability level. Similar trends were also observed in case of quality traits of sugarcane. Investigating the water productivity index for sugarcane and sugar yield it showed that treatments were significant in terms of the space between emitters at 1% probability level. The maximum sugarcane yield was observed in the treatment with a space between emitters of 50 cm, and 20 cm of installation depth. At 60 cm space the emitters of 60 cm and the installation depth of application of 20 cm, the highest water productivity was obtained, reaching 7.18 and 0.87 kg/m3 for produced sugarcane and sugar respectively.

Comparative Study of the Field Performances of Pressure-Grouted Micropiles Using Gravity and Packers

When underground space requires excavation in areas below the water table, the foundation system suffers from buoyancy, which leads to the uplifting of the superstructure. A deep foundation system can be used; however, in cases where a hard layer is encountered, high driving forces and corresponding noises cause civil complaints in urban areas. Micropiles can be an effective alternative option, due to their high performance despite a short installation depth. Pressurized grouting is used with a packer to induce higher interfacial properties between micropile and soil. In this study, the field performance of micropiles installed using gravitational grouting or pressure-grouted using either a geotextile packer or rubber packer was comparatively evaluated by tension and creep tests. Micropiles were installed using pressure grouting in weak and fractured zones. As results, the pressure-grouted micropiles showed more stable and stronger behaviors than ones installed using the gravitational grouting. Moreover, the pressure-grouted micropile installed using the rubber packer showed better performance than the one using the geotextile packer.

Productivity Analysis of Micro-Trenching Using Simphony Simulation Modeling

Micro-trenching is an innovative method for installing fiber optic cable in residential areas and business districts which minimizes surface scarring and potential negative social and environmental impacts. This method has three major steps including cutting a narrow trench in the pavement, cable installation and trench backfilling. This paper discusses a Simphony simulation model of the micro-trenching procedure and analyzes its productivity. Brief descriptions of the micro-trenching method and two field installations used to validate the model are included. A simulation model was developed for two different installation depths of 7.6 and 23 cm using two different methods. To provide an estimation of project duration, the impact of weather conditions on micro-trenching productivity was also considered. The developed model can be used for what if scenarios and for predicting the outcomes, which may be useful for studying the procedure and verifying if any productivity improvement can be achieved. The results indicate that the influence of installation depth is more significant than the impact of weather conditions. Reducing installation depth from 23 cm to 7.6 could improve productivity up to 50% while cold weather condition can reduce productivity by 18.8%. The simulation model demonstrates that the productivity can be improved up to 16% by overlapping two steps during the installation process: starting the cleaning procedure when a portion of cutting is completed. Doi: 10.28991/cej-2020-03091607 Full Text: PDF

Improving the Energy Efficiency of the Use of Borehole Jet Pumps

The article presents rationales for choosing the depth of installation of an oil jet pump in the borehole that which ensures maximum efficiency of its operation. The operating parameters of the ejection system are determined by the joint solution of the characteristic equations of the high-pressure jet pump and the hydraulic system. In the process of solving the system of equations, the method of successive approximations, the Delphi software environment and PTC Mathcad resources were used. The equation of the characteristics of the jet pump hydraulic system was obtained by determining the pressures in its distinctive cross-sections and then presenting their values as the relative (dimensionless) head of the ejection system. Alteration the installation depth of the jet pump changes the characteristics of its hydraulic system, the parameters of the operating point of the pumping unit and its efficiency. In this case, the minimum permissible installation depth of the jet pump is determined by the value of the minimum pressure in the elements of the ejection system, which must exceed the value of the elastic pressure of saturated vapors of the oil and gas flow and ensure its operation in pre-cavitation mode. The probability of operation of a jet pump in cavitation mode was studied using the Bernoulli, Darcy – Weisbach and flow continity equations. The inversely dependence of the ejection coefficient and efficiency of the jet pump on the depth of its installation in the borehole has been revealed. If the jet pump is installed in the borehole at the optimal depth, its efficiency is increased by 30 %.

SIMULATION OF FORCE ACTION ON OSCILLATING PLOUGHSHARE OF HARVEST MACHINE

The dynamics of the drive of the digging mechanism with oscillating ploughshare is investigated. To determine the input impact, a model of the ploughshare-soil interaction process is proposed, based on which the axial forces in the ploughshare connecting rods and moment of resistance on the eccentric shaft are calculated. To verify the adequacy of the model to the experiment, the analytical axial forces and the moment of resistance were compared with the force dependences obtained as a result of tensometric tests. Small oscillations in the drive are investigated on the basis of linear dynamic model. Analytical and empirical functional dependences of the amplitudes of the torques from the oscillation frequency of the drive, operating speed, and ploughshare installation depth are obtained.

Reinforcement Effect of a Concrete Mat to Prevent Ground Collapses Due to Buried Pipe Damage

This study described a ground reinforcement effect of a concrete mat, in order to apply a concrete mat for ground subsidence restoration of an open cut. A concrete mat can prevent the expansion of a cavity and relaxation area underground due to buried pipe damage when the buried pipe is in use. An experimental study was conducted to analyze the stress distribution characteristics of an underground area by ground reinforcement of a concrete mat. In addition, a numerical analysis was performed to estimate the range of underground reinforcement of a concrete mat. As an experiment results, the maximum stress reduction ratio of the concrete mat in the underground was 28.5% to 30.9%, which means the reinforcement effect of the concrete mat, according to the installation depth of the concrete mat. The finite element analysis (FEA) results showed that the installation depth of the concrete mat differed in various scenarios, in order to secure the reinforcement effect of the concrete mat according to the load conditions (point and uniform load). Therefore, the reinforced depth of a concrete mat should be determined by the load type on the surface.

Can We Trust High-Frequency Content in Strong-Motion Database Signals? Impact of Housing, Coupling, and Installation Depth of Seismic Sensors

Seismic hazard studies provide indicators of seismic motion that are expressed for “free-field,” that is, representative of the ground motion exactly at the free surface, without disturbances due to interactions between soil and buildings or other structures. Most of these studies are based on ground-motion prediction equations, which are, themselves, formulated to predict free-field motion, as they are derived from similarly free data. However, is this really the case? In this study, we use several examples to illustrate how small structures hosting permanent strong-motion stations (often anchored on small concrete slabs) generate soil–structure interaction effects that can amplify the high-frequency part of the earthquake signal (>10 Hz) by up to a factor of 2–3 for stations on soils. We also show that the installation depth of a station, even if very shallow (i.e., a few meters), can change the recorded response, mainly by deamplifying the signal in high frequencies (>10 Hz) by a factor up to 0.3. Such effects imply that there are actual differences between recorded and true free-field signals. Depending on the housing conditions, these effects can have significant impact on response spectra at high frequencies, and on measurements of the κ parameter. It is, thus, becoming clear that such effects should be taken into account in studies involving high-frequency seismic motion. To do so, scientists need a detailed description of the conditions of installation and housing of seismological and accelerometric stations, which often lacks from the metadata distributed through the various, commonly used web services. Increasing such information and facilitating the access to it would allow the identification of stations that are problematic and of those that are truly close to free-field recording conditions. In a subsequent step, it would be important to quantify the modification curve of the response of stations that experience such effects.

Water well logging and automatic log interpretation technology

<p>The presented work is fully practical. Hydrogeological (water) well logging is very different from a petroleum well logging in terms of equipment and budget. A water uplift well cost is quite low, and it is not make a big economic sense to use automatic well logging systems for it. Hence, a lot of engineers are trying to "invent" their own resistivity logging tools or just use a conventional AMNB equipment for surface electrical prospecting to explore the water wells. It is feasible, because a water depth and, consequently, the logging cable length is usually limited by 200 m, it is not hard to pull the cable manually. Such a solution is very cheap and easy to implement. However, the process of logging take time and includes hundreds of steps. So, errors in the process is often.</p><p>The aim of this work is to adapt electric resistivity imaging system SibEr for well logging, simplify the logging process and create the possibility for a well drilling team to make the well logging themselves, including the recommendation of the filter installation depth.</p><p>The solution includes:</p><p>- Hardware: well logging cable with 32 (24) takeouts at the bottom hole end with 20 cm spacing;</p><p>- Embedded software for resistivity and induced polarization data acquisition;</p><p>- Data processing software to create the logging report with diagrams and suggested filter intervals.</p><p> </p>

ANALISIS PENGGUNAAN PREFABRICATED VERTICAL DRAINS (PVD) PADA TANAH LEMPUNG LUNAK YANG TERDAPAT LAPISAN LENSA

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.