Analysis of Foundation Pit Design of Metro Station in Complex Environment

The complex engineering geological conditions and the surrounding environmental conditions of the existing subway lines and adjacent buildings have significantly deepened the difficulty of metro station foundation pit design and construction. Based on the foundation pit project of Luboyuan Station of Nanjing Metro Line 9, this study chooses a reasonable foundation pit support design scheme to carry out related research by analyzing the site geological environmental conditions. Through the analysis and evaluation of the engineering geological conditions of the engineering site, the engineering geological problems that may occur in the process of construction are given. According to the lithologic characteristics of the site strata, the hydrogeological conditions, and the features of the underground engineering structure, the design of the foundation pit supporting system is optimized and analyzed. The results show that making full use of the geological features of strata and adopting effective support methods can ensure the safety of foundation pit construction, reduce the cost of engineering description, and shorten the construction period, which can be used as a reference for similar projects and construction.

Optimum Open Pit Design for Kenticha Tantalite Mine, Southern Ethiopia

The mining sector’s share in Ethiopia’s economy is gradually increasing. Among metallic mines, Legadembi for gold and Kenticha for tantalum are the main contributors. At Kenticha, the Ethiopian Mineral Development Share Company is producing tantalite concentrate of 40-60% grade by open pit mining. The mine area is comprised of the rocks of Neoproterozoic age, pegmatite, granite, serpentinite, and talc-chlorite schist. The ore-bearing pegmatite intruding the basement serpentinite, and talc schist rocks, is asymmetric, N-S trending, and locally affected by fractures and local faults. Mining, at present, is being done using conventional methods not by developing benches. An optimum open pit design is developed and its impact on the run of mine is evaluated based on the field data, technical mine report data, borehole data, tonnage data, grade data, and mine survey. The suggested design has taken into account the mine drainage, bench design, haul road design, and mine waste dump design. Also keeping in view the future mining and production requirements. The suggested open pit mine design can minimize the dilution and improve the ore recovery.

Personal income tax design and background-related earnings advantages: evidence from Italy and Poland

PurposeThe authors analyse how the association between parental background and adult children's earnings changes when net rather than gross children's earnings are considered and disentangle what such changes depend on: differences between pre and after taxes earnings inequality or reranking of individuals along the earnings distribution before and after taxes.Design/methodology/approachUsing data from European Union Statistics on Income and Living Conditions (EU-SILC) 2011, the authors focus on two large European countries, Italy and Poland, with comparable levels of inequality and background-related earnings premia but very different personal income tax (PIT) design and estimate – at both the mean and the deciles of the earnings distribution – the association between parents' characteristics and children's gross and net earnings.FindingsThe authors find that in Italy the PIT reduces the magnitude of the association between parental background and adult children's earnings at the top of the distribution, while no effects emerge for Poland, and the reduction is mostly due to a decrease in earnings inequality rather than to a re-ranking of children along the distribution. The findings are confirmed when the authors simulate the introduction of a “quasi flat tax” regime in Italy.Social implicationsThe findings suggest that the higher the tax progressivity, the higher the background-related inequality reduction and the lower the intergenerational association, signalling that the degree of progressivity amongst children may be an effective weapon to reduce intergenerational inequality.Originality/valueIn the literature on intergenerational inequality, the role of taxes is usually overlooked. In this paper, the authors try to fill this gap and enquire how the PIT design affects the association between parental background and adult children's earnings.

Designing Cuckoo Based Pending Interest Table for CCN Networks

<p class="JESTECAbstract">Content Centric Networking (CCN) is a modern architecture that got wide attention in the current researches as a substitutional for the current IP-based architecture. Many studies have been investigated on this novel architecture but only little of them focused on Pending Interest Table (PIT) which is very important component in every CCN router. PIT has fundamental role in packet processing in both upstream process (Interest packets) and downstream process (Data packets). PIT must be fast enough in order to not become an obstruction in the packet processing and also it must be big enough to save a lot of incoming information. In this paper, we suggest a new PIT design and implementation named CF-PIT for CCN router. Our PIT design depends on modifying and utilizing an approximate data structure called Cuckoo filter (CF). Cuckoo filter has ideal characteristics like: high insertion/query/deletion performance, acceptable storage demands and false positive probability which make it with our modification convenient for PIT implementation. The experimental results showed that our CF-PIT design has high performance in different side of views which make it very suitable to be implemented on CCN routers.</p>

Delay effect of mud loading to the open pit design in terms of meeting 2018 – A coal production target case study of pit XYZ at South Kalimantan

Based on the 2018, there a mining plan, two temporary sumps, namely the ABC and BCD sumps. They located in a mining sequence pattern. These sumps required a mud loading process prior to mining the coal below the sequence. The mud loading process is loaded sequentialy. However, the problem occurs when the mud loading process in the ABC sump is delayed, and resulted only 42% of mud production. Such the delay resulted in hindering the mining sequence pattern which forced changes in plans, designs, and decrease of coal production. These condition led to study the cause, impact, and alternative solution of the delay during mud loading process. The method used in this study includes direct observations and data collection of working conditions, equipment capabilities, material properties, and operation timeline. In this study, the statistical analysis is used to determine the cause and effect of delayed mud loading process. A Minex Software is then used to simulate the alternative of redesign the mining sequence pattern. The study found that the delay in mud loading process is due to the external and internal factors, that result in underproduction of coal only 505,833 tons, and delayed of coal production around 64 days. An alternative that can be conducted is to change the direction progress to the area that has low stripping ratio. Factors that can hinder the progress are need to be considered for anticipating the plan distraction at mid-term-plan.

P PEMODELAN DESAIN PIT DAN SEQUENCE PENAMBANGAN BATUBARA UNTUK MEMENUHI TARGET PRODUKSI DENGAN MENGGUNAKAN SOFTWARE MINESCAPE 4.119 DI PT BUKIT ASAM, TBK. TANJUNG ENIM, SUMATERA SELATAN

Pemodelan desain tambang ialah proses untuk mencapai (ultimate pit limit) dalam jangka waktu tertentu secara aman dan menguntungkan, urutan penambangan bulanan/tahunan, penjadwalan produksi dan waste dump. Tujuan pemodelan desain ialah untuk mempermudah penjadwalan produksi baik tahunan, bulanan hingga mingguan/harian. Sebelum pembuatan desain pit yang diperlukan adalah lebar bench,tinggi bench, kemiringan bench, lebar jalan angkut, serta peta situasi. Tahapan pembuatan desain pit diawali dari pembuatan boundary pit, pembuatan project and offset, pembuatan triangles, pembuatan intersection pit design dengan peta situasi, pembuatan clip world, pembuatan cross section, pembuatan plotting, serta perhitungan reserves. Produksi batubara pada pit Barat bulan April 2019 sebesar 264.000,000 ton serta dengan menggunakan software Minescape 4.119 sebesar 298.240,390 ton dan SR yang didapat 5:1 yang artinya 5 volume overburden dan 1 volume tonase batubara.

Plasticity in extended phenotypes: how the antlion Myrmeleon crudelis adjusts the pit traps depending on biotic and abiotic conditions

The physical structures built by animals are considered extended phenotypes that reflect how organisms make decisions and deal with changes in their biotic and abiotic environment. We summarize the results of several studies on Myrmeleon crudelis, a neuropteran larva that digs pit-traps in the soil to capture small arthropods (mostly ants) in the tropical dry forests of Costa Rica. Specifically, we showed how this species responds to varying biotic and abiotic conditions with changes in the design and/or location of its pit traps. Several experiments and field comparisons indicate that: 1) antlions adjust the pit design according to the abundance and type of prey. When prey is scarce, antlions increased trap diameter, an architectural adjustment that enhances the probability of prey encounter. Antlions that experienced high prey abundance, but the prey easily escaped, then increased pit depth, an adjustment that increases the chance of prey retention; 2) soil compaction strongly reduced pit-trap size and abundance; 3) antlions preferred soils with high proportion of fine-particle size to build pits. In fine-grained soil, pit-traps are larger and more efficient to capture prey than traps in coarse-grained soils; and 4) pit-traps may also be affected through indirect effects of soil structure and vegetation cover. Areas with fine-soil presented less plant cover, and plant cover could be beneficial for antlions because it acts as a shelter against direct sunlight and rainfall, or it may represent a cost because it is a source of leaflitter falling in the pits. The works summarized here how trap-building predators can exhibit considerable flexibility in trap construction in response to various biotic and abiotic factors, emphasizing how the study of extended phenotypes can be a useful approach to better understand the flexibility of foraging behaviors.