Wastewater

Every community produces both of liquid and solid wastes and air emissions. The liquid waste (wastewater) is essentially the water supply of the community after it has been used in a variety of applications. The sources of wastewater may be defined as a combination of the liquid of water-carried wastes removed from recidences, institutions, commercial and industrial establishment. When untreated wastewater accumulates in the septic, the decomposition processes of the organic contains.

Character of natural deposits: Bedrock and Residual Soils

Defect in Unweathered Bedrocks

The foundation engineer is commonly not seriously troubled by structural defects in the bedrock. However, certain types of rock deverse careful scrutiny.
Limestone and, to a less extent, dolomite are soluble in groundwater. Strata of these rocks may contain large channels, often filled with clay, or even extensive caverns. The absence of surface drainage or the presence of shink holes in limestone region is indicate of solution cavities. Such cavities may endanger the stability of foundations and must be located.

Lunar Solar Power Generation -LUNA RING-

The Energy Paradigm Shift Opens the Door to a Sustainable Society

A shift from economical use of limited resources to the unlimited use of clean energy is the ultimate dream of all mankind. The LUNA RING, our lunar solar power generation concept, translates this dream into reality through ingenious ideas coupled with advanced space technologies.
Virtually inexhaustible, nonpolluting solar energy is the ultimate source of green energy that brings prosperity to nature as well as our lives. Shimizu Corporation proposes The LUNA RING for the infinite coexistence of mankind and the Earth.

What is Soil-Cement?

Compacting CTBSoil-cement is a highly compacted mixture of soil/aggregate, cement, and water. It is widely used as a low-cost pavement base for roads, residential streets, parking areas, airports, shoulders, and materials-handling and storage areas. Its advantages of great strength and durability combine with low first cost to make it the outstanding value in its field. A thin bituminous surface is usually placed on the soil-cement to complete the pavement.

What Type of Soil is Used?

The soil material in soil-cement can be almost any combination of sand, silt, clay, gravel, or crushed stone. Local granular materials, such as slag, caliche, limerock, and scoria, plus a wide variety of waste materials including cinders, fly ash, foundry sands, and screenings from quarries and gravel pits, can all be utilized as soil material. Old granular-base roads, with or without bituminous surfaces, can also be reclaimed to make great soil-cement. Soil-cement is sometimes called cement-stabilized base, or cement-treated aggregate base. Regardless of the name, the principles governing its composition and construction are the same.

How is Soil-Cement Built?

Before construction begins, simple laboratory tests establish the cement content, compaction, and water requirements of the soil material to be used. During construction, tests are made to see that the requirements are being met. Testing ensures that the mixture will have strength and long-term durability. No guesswork is involved. Applying dry cementSoil-cement can be mixed in place or in a central mixing plant. Central mixing plants can be used where borrow material is involved. Friable granular materials are selected for their low cement requirements and ease of handling and mixing. Normally pugmill-type mixers are used. The mixed soil-cement is then hauled to the jobsite and spread on the prepared subgrade. Compaction and curing procedures are the same for central-plant and mixed-in-place procedures. Mixing cement into soilThere are four steps in mixed-in-place soil-cement construction; spreading cement, mixing, compaction, and curing. The proper quantity of cement is spread on the in-place soil material. Then the cement, the soil material, and the necessary amount of water are mixed thoroughly by any of several types of mixing machines. Next, the mixture is tightly compacted to obtain maximum benefit form the cement. No special compaction equipment is needed; rollers of various kinds, depending on soil type, can be used. The mixture is cemented permanently at a high density and the hardened soil-cement will not deform or consolidate further under traffic. Applying bituminous primeCuring, the final step, prevents evaporation of water to ensure maximum strength development through cement hydration. A light coat of bituminous material is commonly used to prevent moisture loss; it also forms part of the bituminous surface. A common type of wearing surface for light traffic is a surface treatment of bituminous material and chips ½ to ¾-inch (13 to 19 mm) thick. For heavy-duty use and in severe climates a 1-1/2-inch (38 mm) asphalt mat is used. Contractors bidding on soil-cement jobs know that construction will be relatively easy and problem-free; weather delays rare; and reworking of completed sections unnecessary.

Why Use Soil-Cement?

Failing granular-base pavements, with or without their old bituminous mats, can be salvaged, strengthened, and reclaimed as soil-cement pavements. This is an efficient, economical way of rebuilding pavements. Since approximately 90% of the material used is already in place, handling and hauling costs are cut to a minimum. Many granular and waste materials from quarries and gravel pits can also be used to make soil-cement; thus high-grade materials are conserved for other purposes. Highway and city engineers praise soil-cement’s performance, it’s low first cost, long life, and high strength. Soil-cement is constructed quickly and easily – a fact appreciated by owners and users alike.

How Does Soil-Cement Perform?

Soil-cement thicknesses are less than those required for granular bases carrying the same traffic over the same subgrade. This is because soil-cement is a cemented, rigid material that distributes loads over broad areas. Its slab-like characteristics and beam strength are unmatched by granular bases. Hard, rigid soil-cement resists cyclic cold, rain, and spring-thaw damage. Old soil-cement pavements in all parts of the continent are still giving good service at low maintenance costs. Soil-cement has been used in every state in the Untied States and in all Canadian provinces. Specimens taken from roads show that the strength of soil-cement actually increases with age; some specimens were four times as strong as test specimens made when the roads were first opened to traffic. This reserve strength accounts in part for soil-cement’s good long-term performance. Is Soil-Cement Economical? The cost of soil-cement compares favorably with that of granular-base pavement. When built for equal load-carrying capacity, soil-cement is almost always less expensive than other low-cost pavements. Economy is achieved through the use or reuse of in-place or nearby borrow materials. No costly hauling of expensive, granular-base materials is required; thus both energy and materials are conserved.

 
soil cement

ESSAY COMPETITION FOR ASEAN YOUNG TALENTS

PII – AAET

ENGINEERING SCIENCE, TECHNOLOGY AND INNOVATION (ESTI)

ESSAY COMPETITION FOR ASEAN YOUNG TALENTS

 

WORKING TOGETHER TOWARDS A LOW CARBON SOCIETY FOR ASEAN

1.  Introduction

The ASEAN Academy of Engineering and Technology (AAET) is a non-profit Civil Society Organisation (CSO) affiliated with the ASEAN Secretariat. The Academy’s  mandate is to promote and support initiatives in Engineering, Science, Technology and  Innovation (ESTI). Through ESTI, the Academy hopes to contribute to a stable, prosperous and highly competitive ASEAN. In Indonesia AAET have a colabaration with  Persatuan Insinyur Indonesia (PII).

EKSPEDISI GEOGRAFI INDONESIA BAKOSURTANAL 2011, KARST GUNUNGSEWU

Tahun 2011, merupakan tahun ketujuh pelaksanaan Ekspedisi Geografi Indonesia, setelah 8 lokasi ekspedisi yang telah dilakukan, yaitu Gunung Halimun (Jawa Barat) pada tahun 2005, Pangandaran-Pangalengan (tahun 2006), Bali (bagian utara) pada tahun 2007, Sulawesi Selatan (2008), Gorontalo dan Sumatera Utara (2009), Jawa Timur dan NTB (2010). EGI BAKOSURTANAL ke-IX 2011 kali ini bertajuk Ekspedisi Karst Gunungsewu yang berlokasi di Pantai Selatan DIY-Jawa Timur, mulai dari Kabupaten Wonosari (DIY), Wonogiri (Jawa Tengah) hingga Pacitan (Jawa Timur).

Dipilih lokasi Gunungsewu karena merupakan daerah karst yang memiliki berbagai keunikan yang menarik, baik dari aspek biotik, abiotik maupun sosial-budayanya. Karst Gunungsewu merupakan rangkaian Pegunungan Selatan Jawa yang membentang dari Pantai Parangtritis Yogyakarta sampai dengan Pantai Teleng Ria di Pacitan Jawa Timur. Karst Gunungsewu secara administratif berada di Kabupaten Gunungkidul Provinsi Yogyakarta, Kabupaten Wonogiri Provinsi Jawa Tengah, dan Kabupaten Pacitan Provinsi Jawa Timur.  Karst di Kabupaten Gunungkidul memiliki luas 13.000 km² dan secara khusus mendapat perhatian dari kalangan internasional karena merupakan ekotipe bentang alam karst khas daerah beriklim tropis basah.
Tim EGI Karst Gunungsewu berjumlah 25 orang terdiri dari berbagai ahli dan disiplin ilmu Survei dan Pemetaan, Penginderaan Jauh, karstologi, Arkeologi, Antropologi dan Speleologi yang berasal dari Bakosurtanal, UGM, UI dan ITB. Ikut serta juga dalam Tim Ekspedisi ini anggota Dewan Pertimbangan Presiden, termasuk Ibu Meutia Hatta.

Ekspedisi Geografis Indonesia Bakosurtanal 2011 bertujuan untuk menemukenali dan menggali sesuatu yang baru dari Karst gunungsewu. Ada 3 parameter utama yang dicarai dan dikaji dalam ekspedisi kali ini, yaitu abiotik, biotik dan budaya yang tersusun dalam kerangka kajian:
1.    Kronologi Terbentuknya Lahan di Gunungkidul, mulai dari pengendapan gamping sampai terbentuknya lahan saat ini.
2.    Evolusi Bentuklahan
3.    Biodiversitas di kawasan karst
4.    Sejarah Hunian
5.    Sosiokultural
6.    Degradasi Lingkungan
7.    Visualisasi Spasial

Ekspedisi rencana dilaksanakan selama 6 hari, 10 – 15 Juli 2011. Hari pertama, tim ekspedisi berangkat dari Kota Jogjakarta menuju Kantor Bupati Gunungkidul untuk mengikuti acara penyambutan dan pelepasan kegiatan EGI. Tim diterima oleh jajaran pejabat dan staf di lingkungan Kantor Bupati Gunungkidul.

Disampaikan oleh Bupati Gunungkidul dalam sambutannya yang dibacakan oleh Asisten Perekonomian dan Pembangunan, Ir. Budi Martono, M.Si bahwa kunjungan Tim Ekspedisi Geografi BAKOSURTANAL di Kabupaten Gunungkidul ini akan menjadi momentum yang tepat guna mengetahui dan memahami secara khusus dan intensif terhadap permasalahan terkait dengan kondisi geografis Kabupaten Gunungkidul. Kepada Tim EGI Bupati berharap fenomena yang terjadi di Gunungkidul ini akan menjadi bahan kajian yang sangat bernilai guna menentukan solusi terbaik terhadap upaya pelestarian kawasan karst, maupun peningkatan daya dukung masyarakat terhadap kelestarian kawasan karst.

Kegiatan hari pertama dalam ekspedisi ini lebih banyak bertujuan untuk melakukan overview terhadap wilayah kajian. Situs pertama yang dikunjungi berada di wilayah Desa Bedoyo. Di lokasi ini dilakukan pengamatan morfologi tipikal karst Gunungsewu dimana tampak pola-pola tipikal Kegel berupa bentukan kerucut-kerucut. Material kapur di wilayah ini memiliki kandungan CaCO3 yang paling tinggi (di atas 70%), sehingga batu kapur disini banyak ditambang oleh penduduk.

Perjalanan dilanjutkan ke Desa Sindon, Kecamatan Semanu untuk mengamati fenomena sungai bawah tanah Bribin. Sungai bawah tanah merupakan fenomena khas yang terjadi di daerah Karst. Di lokasi ini, sungai bawah tanah dimanfaatkan airnya dengan pembuatan sumur menembus sungai bawah tanah tersebut untuk selanjutnya air dipompa ke atas dan didistribusikan. Kedalaman sungai bawah tanah di titik ini mencapai 105 meter di bawah permukaan tanah.

Lokasi tujuan selanjutnya adalah telaga karst, merupakan sebuah telaga di daerah karstyang terisi air saat musim penghujan. Telaga inilah yang merupakan salah satu pintu dimana sungai bawah tanah tadi mendapatkan suplai air.

Selain fenomena biaotik dan abiotik, budaya merupakan salah satu aspek utama yang dikaji dalam Ekspedisi ini. Terkait dengan aspek budaya, Tim Ekspedisi menemukan suatu tradisi bersih Desa yang oleh mayarakat Gunungkidul biasa disebut dengan istilah “Rosulan”. Tradisi Rosulan ini merupakan tradisi yang diadakan setiap tahunnya pada bulan Rajab, sebagai ungkapan syukur terhadap segala anugrah dan karunia Sang Pencipta. Pada tradisi ini, masing-masing Dusun atau Golongan memberikan hasil budidayanya untuk diarak bersama di ke Balai Desa.

Hasil dari pengamatan fenomena dituangkan setiap peserta Ekspedisi Geografi Indonesia sesuai dengan tugas dikelompoknya dalam bentuk tulisan, dan akan dikemas berbentuk buku ilmiah popular dan multimedia yang diharapkan akan mampu membangkitkan rasa kesadaran akan lingkungan dan pentingnya menjaga ekosistem karst.

Oleh: Arif Aprianto

What is a geotechnical engineer?

Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. Geotechnical engineering uses principles of soil mechanics and rock mechanics to investigate subsurface conditions and materials; determine the relevant physical/mechanical and chemical properties of these materials; evaluate stability of natural slopes and man-made soil deposits; assess risks posed by site conditions; design earthworks and structure foundations; and monitor site conditions, earthwork and foundation construction

Hibah MITI 2011

Kompetisi HIBAH MITI 2011
“Bangkitlah Pemuda Untuk Indonesia Jaya”

Sebagai suatu bentuk tanggung jawab kami sebagai pemuda, generasi penerus bangsa, maka MITI-Mahasiswa (Masyarakat Ilmuwan dan teknolog Indonesia- Mahasiswa) mengajak kepada rekan-rekan mahasiswa di seluruh Indonesia untuk:

GEO5 programs for geotechnical design and analysis

The GEO5 suite of programs is designed to solve various geotechnical problems. The easy-to-use suite consists of individual programs with a unified user-friendly interface. Each program is used to analyse a different geotechnical task, however all modules communicate with each other to form an intergrated package.

What is the function of a sand layer underlying paving slab/interlocking blocks?

Normally after the laying of sub-base layer of the paving slab/interlocking blocks, a 30mm thick sand bedding is screeded and tamped over the pavement area. Then paving slabs are laid horizontally with joints of 2-3mm wide and are laid in uphill direction. After completing the laying of paving slabs, sand used for filling joints is spread over the surface of the units and brushed into the joints such that all joints are completely filled. The paving slabs are then bedded into final position by using plate vibrators.

The sand layer serves the same purpose of normal blinding layer under concrete structure:

(i) Provide a level and flat surface for the paving slab/interlocking blocks to lay on;
(ii) Protect the foundation (i.e. underground subgrade and sub-base layer) against adverse outside conditions (e.g. bad weather) during construction of the laying work of paving slab/interlocking blocks.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
engineeringcivil.com