Earthquake is a disaster that often happened in Indonesia. Tectonic earthquake in scaleof 5,9 Richter scales happened in Yogyakarta, Klaten and some other towns in Central Java, at 27May 2006. In Klaten Regency there are a lot of hydro infrastructure damage as a result ofearthquake. This damage causes disturbance to quantity and quality of agriculture. This researchaim to map condition of hydro infrastructure damage in Klaten Regency and analyses cause ofdamage.Data collecting has been done through site observation and interview with Sub DinasPengairan Kabupaten Klaten, BAPPEDA KLATEN and related institution.This research indicatesthat earthquake has cause damage at hydro infrastructure. The damage grouped in riverinfrastructure, irrigation infrastructure and housing infrastructure on duty, in the level of light untillhard damage. The damage of hydro infrastructure caused by stripper of dam, dam position thatstays precise at earthquake path, dam construction were not fulfills requirement and damfoundation unable to detain building payload. Â Gempa bumi merupakan bencana yang sangat sering terjadi di Indonesia. Gempatektonik dengan skala 5,9 skala Richter terjadi di wilayah Yogyakarta, Klaten dan beberapa kotalain di Jawa Tengah, pada hari Sabtu tanggal 27 Mei 2006. Di Kabupaten Klaten banyak terdapatbangunan air yang juga mengalami kerusakan akibat gempa bumi. Kerusakan ini menimbulkangangguan terhadap kuantitas dan kualitas produksi pertanian. Penelitian ini bertujuan untukmemetakan kondisi kerusakan bangunan air akibat gempa yang terjadi di Kabupaten Klaten danmenganalisis penyebab kerusakan bangunan air tersebut.Pengumpulan data dalam penelitian inidilakukan melalui observasi serta wawancara dengan Sub Dinas Pengairan Kabupaten Klaten,BAPPEDA Klaten dan instansi lain yang terkait. Hasil penelitian menunjukkan bahwa gempa bumitelah menimbulkan kerusakan pada bangunan infrastruktur keairan, yang dikelompokkan dalamkerusakan infrastruktur sungai (tanggul, bendung), infrastruktur irigasi (bangunan dan saluran) daninfrastruktur rumah dinas, dengan tingkat kerusakan ringan hingga rusak parah. Adapun sebagaipenyebab kerusakan pada bangunan infrastruktur keairan adalah umur bendung yang sudah tua,posisi bendung berada tepat pada alur gempa, konstruksi bendung yang tidak memenuhipersyaratan serta gempa menyebabkan pergeseran tanah, sehingga pondasi tidak mampumenahan beban bangunan.
Abstract To protect the estuary from sedimentation and waves need a jetty structure. This study discusses the alternative jetty design to be simulated for waves and sediments. The research was located in Batang Regency, Central Java Province. The study objective is to simulate wave and sediment for alternative estuary protection. Preliminary data are collected include topography and bathymetry, tidal observation data that include research area. The secondary data were wind data from BMKG of Semarang Station. The wind data used was each hour data for 16 years in the years 2004 to 2019. To simulate the wave and sediment, a software MIKE was used for the two alternative design. The first alternative using 2 jetties with 100 m length and the second alternative using two jetties with addition length for east side. Based on the sediment transport simulation result, the second alternative design put less 5 cm a year then the first alternative. The evaluation based on cost, time period construction, construction methods, According to the scoring, the first alternative design will be choose to the design and construction step.
The present paper reports a study conducted to examine several sands with a large spread of particle size in order to validate the modelling of both Darcy's and Forchheimer's law parameters, which could be applied to any kind of sand. An experimental set-up has been specially conceived to generate hydraulic gradients within fine sands higher than 600. We also present an attempt at using a capillary-type flow model to determine structural parameters of sand and predict pressure gradients. The specific surface areas calculated appear to be consistent with surface areas estimated from screening experiments. Similarly, tortuosity values calculated from pressure drop experiments stand within the range of values found in the literature, measured using an alternative method, the conductometric method. Using one dimensionless equation of the capillary-type flow model, a single value of the pore Reynolds number makes it possible to determine, whatever the porous medium, the limits of Darcy's flow regime. This Reynolds number value is 4.3.
Abstract This paper presents the design and testing procedures for a new type of permeameter that combines the methods of a constant-head permeameter for large hydraulic gradients (used to simulate hydraulic gradients in centrifuged geotechnical models) and a sinusoidal head permeameter (used to simulate internal flow in soils due to waves). The flow of permeant through a granular soil specimen is forced by a pump with a control servovalve used to regulate the flow rate according to the desired signal. The measurement instruments, which consist of temperature sensors, differential pressure transducers, flowmeters, and an electrical controller, are linked to a microcomputer and a data acquisition and control system that permits full automation of the tests. Steady flow tests, carried out on fine sands with high hydraulic gradients, show that the flow is governed by Forchheimer's law. The analysis of the transient flow tests, carried out on fine sands, has shown that the classical Darcy's law is not valid when the material is subjected to a flow simulating a wave; a generalization of Darcy's law for this type of flow is proposed here.
Many areas of the northern coastal in Central Java, Indonesia, have been suffering from damage. One of the areas is Jepara, which has been experiencing this kind of damage for 7.6 kilometres from total 72 kilometres long beach. All damages are mostly caused by coastal erosion, sedimentation, environment and tidal flooding. Several efforts have been done, such as replanting mangroves, building revetment and groins, but it still could not mitigated the coastal damage. The purposes of this study are to map the coastal damages, to analyze handling priority and to determine coastal protection model. The method used are by identifying and plotting the coastal damage on the map, assessing score of each variable, and determining the handling priority and suitable coastal protection model. There are five levels of coastal damage used in this study, namely as light damage, medium, heavy, very heavy, and extremely heavy. Based on the priority assessment of coastal damage, it needs to be followed up by designing in detail and implementing through soft structure for example mangrove, sand nourishes and hard structure, such as breakwater, groins and revetment.
