A new slip surface in noncohesive slopes

Determining the slope slip surface is difficult, prominent and uncertain. Slip-surface are utilized to estimate slope safety. This study aimed at investigating the slip surface caused by statistical loads by using experimental testing methods. The experimental method was conducted by providing a statistical load on the sand slope The load was used until the slope collapsed. Sand slopes were modeled in a glass box measuring 110 cm x 40 cm x 10 cm. The sand material used was sand that passed through sieve no.10 and was held by sieve no. 200. At a distance of 2.5 cm horizontally and at a distance of 5 cm vertically, colored marks were used to see the pattern of grain movement. Observations were conducted until the slope collapsed. The collapse pattern revealed in the experimental method is non-circular.

Desertification and Its Control along the Qinghai-Tibet Railway

The Qinghai-Tibet Railway is a magnificent project in the twenty first century. However, the problem of land desertification has arisen during the operation of the railway. Many sections of the railway roadbed are buried by sand. The ecological safety along the railway and the safe operation of the railway have attracted worldwide attention. This chapter will focus on the current situation of desertification along the Qinghai-Tibet Railway, such as key desertification sections and the temporal and spatial characteristics of the occurrence of desertification. At the same time, it introduces the characteristics of the dynamic conditions of railway desertification and the source of sand material. It is divided into two parts: biological measures and engineering measures to introduce desertification control along the railway. The biological measures focus on the selection of Lolium perenne, Festuca sinensi, Elymus breviaristatus, Elymus nutans and Poa crymophila, and other alpine native sand-fixing plant materials. The engineering measures will introduce the railway desertification comprehensive prevention and control technology system that combines solidification, resistance, and transportation.

Laboratory test and analysis of recovery from separation of iron sand using magnetic separator

The iron sand mining is a prevalent practice because such a material is a mineral with many uses, including as a raw material in the iron and steel industry. In mining, iron sand certainly carries other minerals as impurity minerals. Thus the iron sand needs a further processing to increase the content of the iron itself. The widely used method is using a magnetic separator since the iron ore is a material that is strongly attracted by magnetic force. In contrast, the impurity material is repelled by magnetic forces so that the separation of iron sand from impurities can be carried out properly. The purpose of this study is to increase the content of valuable minerals available in the iron sand material. The variables used in this study includes the strong electric current and the size of iron sand. This study obtained a maximum result at a material size of 100 mesh with a current strength of 5 amperes with the acquisition of concentrates as much as 165,189 grams and a recovery value of 65,041%.

SPECIAL ASPECTS OF DEFORMATION OF COASTAL PROFILE DURING A FULL STORM CYCLE

Deformations of the coastal accumulative profile during a full storm cycle can be related both to the special aspects of individual storms and to seasonal cycles of wave activity. There is a concept of a “winter” and a “summer” type of coastal profile. The difference between these types of profiles is the isolation of the outer underwater berm in winter due to the transfer of sand material to depth and an increase of slopes in the surf zone in summer due to the transfer of sand material to the shore. In this case, the post-storm relief is determined by the character of the wave intensity reduction phase, i.e., the storm attenuation phase. The attenuation of the storm can be prolonged and accompanied by local peaks in wave heights, which will decrease gradually. In this case, the storm has a high potential for beach recovery and the underwater berm may shift toward the shore. In another case, storm attenuation can occur relatively quickly – the original profile is not recovered and at the end of the storm, the profile shape reflects the erosion in the peak phase. Relevant is the determination of the special features of the resulting deformations at the end of the storm cycle, in particular at the end of the storm attenuation phase. In this paper, the special features of storm deformations of the coastal sand profile, which were observed during field experiment on the Bulgarian coast and during monitoring observations on the Baltic Spit, are considered. In one case (the Bulgarian coast) it is a transition from the typical “summer” profile to the “winter” profile. In another case (Baltic Spit), a shift of the outer underwater berm toward the shore was revealed, which can be considered as a transition to the “summer” profile. It is revealed that the features of the storm attenuation stage in the two cases under consideration have specific differences. It is shown that transformations of the coastal profile, characterized as seasonal, can occur during the full cycle of a single storm event.

Local Wisdom of Builders on The Quality of Making Concrete in Kendari City Southeast Sulawesi Province

In Kendari City, the concrete structure made by construction workers consists of: (a) concrete for the lower class; (b) concrete for middle society, and; (c) concrete for the upper community. The concrete is made with different sand material. This research is important to find out the method of making concrete made by construction workers in Kendari City. This research is intended to test the compressive strength and absorbency of the concrete made by construction workers in Kendari City. This study uses an experimental method with a quantitative approach. Based on laboratory test results that concrete material from 100% Unaha sand with the composition of 1 sack of cement: 4 barrel of unaha sand included in structural concrete. Concrete material from split stone and Pohara sand with a composition of 1 sack of cement: 4 barrel of Pohara sand : 4 barrel of split stone, concrete material from Unaha sand and Pohara sand with a composition of 1 sack of cement: 4 barrels of Unaha sand : 4 barrels of Pohara sand, concrete material from 100% Nambo sand with the composition of 1 sack of cement: 4 barrels of Nambo sand, concrete material from Nambo sand and Unaha sand with a composition of 1 sack of cement: 3 barrels of Nambo sand : 1 barrel of Unaha sand, and concrete material from Nambo sand and Sabulakoa sand with composition of 1 sack of cement : 3 barrels of Nambo sand : 1 barrel of Sabulakoa sand are included in non-structural concrete.

Mathematical Modeling the Dynamics of the Bottom Sediments Granulometric Composition in the Balaklava Bay Affected by the Wind Waves

Purpose. Based on the mathematical modeling methods, influence of the wind waves on redistribution of the sand fractions in the semi-closed estuary-type water area is estimated using the Balaklava Bay as an example. Methods and Results. A two-dimensional version of the XBeach model with a constant grid spacing 10 m was used. The characteristics of wind waves were preset using the JONSWAP spectrum. The calculations were carried out for a storm event lasting about 12 hours once a year. The in-situ data on the particle size distribution in the bottom sediments resulted from the monitoring observations in the Balaklava Bay region was used in the numerical experiments. Conclusions. The results of modeling showed that the basic determining factors regulating the sediments movement were the depth and the bottom slope. It is noted that changing of the bottom inclination angle between the isobaths 6–7 and 7–8 m leads to deposition of the large and medium fractions, and in the area between the isobaths 9–10 and 10–12 m – to accumulation of fine sand. It was revealed that in the Balaklava Bay water area, the main redistribution of sand material caused by the storm waves took place within the southern basin, as well as at the bay exit in the coastal zone of the Megalo-Yalo Gulf. This is primarily determined by the features of the Balaklava Bay coast orography, namely, the knee-shaped narrowness separating the northern and southern basins. Nevertheless, in the isolated northern part of the Balaklava Bay being affected by the storm waves, insignificant dynamics of sand material was observed. The fractions of bottom sediments are redistributed from the western coast to the central part of the basin and to the eastern coast of the bay.

Mathematical Modeling the Dynamics of the Bottom Sediments Granulometric Composition in the Balaklava Bay Affected by the Wind Waves

Purpose. Based on the mathematical modeling methods, influence of the wind waves on redistribution of the sand fractions in the semi-closed estuary-type water area is estimated using the Balaklava Bay as an example. Methods and Results. A two-dimensional version of the XBeach model with a constant grid spacing 10 m was used. The characteristics of wind waves were preset using the JONSWAP spectrum implying fixed height, wave period and various combinations of the wave direction. The calculations were carried out for a storm event lasting about 12 hours once a year. The in-situ data on the particle size distribution in the bottom sediments resulted from the monitoring observations performed by the Marine Hydrophysical Institute, Russian Academy of Sciences, in the Balaklava Bay region was used in the numerical experiments. Conclusions. The results of modeling showed that the basic determining factors regulating the sediments movement were the depth and the bottom slope. It is noted that changing of the bottom inclination angle between the isobaths 6–7 and 7–8 m leads to deposition of the large and medium fractions, and in the area between the isobaths 9–10 and 10–12 m – to accumulation of fine sand. It was revealed that in the Balaklava Bay water area, the main redistribution of sand material caused by the storm waves took place within the southern basin, as well as at the bay exit in the coastal zone of the Megalo-Yalo Bay. This is primarily determined by the features of the Balaklava Bay coast orography, namely, the knee-shaped narrowness separating the northern and southern basins. Nevertheless, in the isolated northern part of the Balaklava Bay being affected by the storm waves, insignificant dynamics of sand material was observed. The fractions of bottom sediments are redistributed from the western coast to the central part of the basin and to the eastern coast of the bay.

Pengawasan Kegiatan Pembangunan Prasarana untuk Meningkatan Kualitas Fisik di Perumahan PNS Bumi Kanjuruhan Kepanjen

ABSTRAKPeningkatan prasarana pada Perumahan PNS Bumi Kanjuruhan sangat diperlukan dimana prasarana merupakan faktor utama yang diperlukan oleh penghuni disamping faktor lokasi dan kualitas bangunan. Memberikan pendampingan secara teknik terhadap pembangunan prasarana menjadi tujuan dari kegiatan ini sehingga hasil pekerjaan sesuai dengan spesifikasi teknis dan waktu pelaksanaan pekerjaan sesuai dengan rencana. Metode yang digunakan adalah pemantauan terhadap jadwal pelaksanaan pekerjaan untuk menghindari keterlambatan pekerjaan serta pemantauan terhadap kualitas bahan yang digunakan. Hasil dari kegiatan pengawasan dilakukan pengukuran bersama akhir 100% dimana dihasilkan pelaksanaan dilapangan sesuai dengan gambar desain awal. Ketepatan waktu pelaksanaan pekerjaan dengan rata-rata capaian prestasi kemajuan pekerjaan minggu ke-1, minggu ke-2, dan minggu ke-3 masing-masing adalah sebesar 28,77%, 70,00% dan 100%, serta bahan bangunan yang dipakai sesuai dengan spesifikasinya seperti pengujian material pasir diperoleh kadar air 3,11%, modulus kehalusan butiran 2,30, berat jenis kering 2,68, berat jenis jenuh 2,78, berat jenis semu 2,95, penyerapan air 3,21% dan kadar lumpur kurang dari 1,4% serta masuk dengan penilaian zona 3. Kata kunci : prasarana; pengawasan; kualitas ABSTRACT Improvement of the infrastructure in PNS Bumi Kanjuruhan housing is indispensable where it’s a primarly factor required by residents besides the location and building quality factors. Providing technical assistance in the construction of infrastructureis the goal of this activity so that the work results are in accordance with the technical specifications and the time of execution of the work in compatible with the plan. The method used is monitoring of work implementation schedules to avoid delays in construction as well as monitoring of the quality of materials used. The results of the monitoring activities were conducted the final mutual check 100% resulting in field execution in accordance with the initial design drawings. Timeliness of the implementation of work with an average achievement in the progress of work the first week, second week, and third week amounted to 28.77%, 70.00% and 100% respectivel, and building materials used in accordance with specifications such as testing of sand material obtained water content 3.11%, granular fineness modulus 2.30, bulk specipic gravity 2.68, saturated specific gravity 2.78, apparent specipic gravity 2.95, water absorption 3.21% and sludge content less than 1.4% and entered with zone 3 assessment.

DEVELOPMENT OF THERMAL INSULATION TILE WITH NON-VENTILATED AIR LAYERS SHIELDED BY FOIL MATERIAL

A heat-insulating tile consisting of a back, side and front wall made of extruded expanded polystyrene and a polymer-sand mixture has been developed. Inside there are two unventilated air layers, separated by a heat-reflecting screen. In order to exclude cold bridges, the thermal insulation tile is made of two parts, offset in the horizontal direction. Fixing of tiles among themselves is carried out by means of occurrence of ledges on the top face of one tile with hollows on the bottom face of another. This type of joining plates ensures the absence of cold bridges and facilitates their installation. The problem is solved by the fact that in the facade thermal insulation panel containing the front, rear walls, side faces and locking elements in the form of protrusions and recesses arranged in a checkerboard pattern, and made with the possibility of mounting, the front and rear walls form a frame with a cavity , filled with insulating material, characterized in that the locking elements are placed on the front faces of the frame. Shielded layers of air are used as heat-insulating material. The frame of the panel is made of polymer-sand material, and for its fastening use an adhesive solution. This is achieved by making a panel of polymer-sand frame, in the middle of which there are shielded air layers, which provide resistance to heat transfer and infrared radiation of the material.