Since 1900, Semarang City has been meeting its industrial water needs by pumping groundwater through its underlying aquifers. The trend toward exploiting groundwater resources has driven the number of deep wells and their production capacity to increase, and therefore leads to the water table to drop from time to time, which has been marked as one of the primary causes of land subsidence there. The main aim of the current study was to numerically model the temporal and spatial evolution of groundwater table under excess abstraction so that a groundwater management strategy can be accordingly drawn up for ensuing the sustainability of groundwater resources in the future. A series of numerical simulations were carried out to take into account hydrogeological data, artificial and natural discharges of deep wells, and boundary effects in Semarang City. The groundwater modeling is calibrated under two flow conditions of the steady state from 1970 to 1990 and the transient state from 1990 to 2005 for six observation wells distributed in Semarang City. Four scenarios that reflect potential management strategies were developed, and then their effectiveness was systematically investigated. The results of our study indicate that the implementation of proper groundwater control management and measure is able to restore the groundwater level to rise back in Semarang City, and in turn achieve the sustainability of groundwater resources.

One way to reduce damage of the pavement structure is to improve the quality of asphalt used. In an effort to improve the quality of the asphalt, additives are added, such as polymers. This study aims to determine the basic characteristics of Low Density Polyethylene Plastic modified asphalt, which includes penetration, softening point, flash and fire point, specific gravity, ductility, viscosity. In addition, it will be determined the maximum content of Low Density Polyethylene Plastic which produces modified asphalt that meets the standards of the Directorate General of Highways. The results of this study show that modified asphalt with Low Density Polyethylene Plastic can increase the asphalt softening point and reduce penetration value, flash and fire point, specific gravity, ductility, and viscosity of asphalt. The maximum LDPE Plastic content that can produce modified asphalt that meets specifications of the Directorate General of Highways is 5%. Keywords: plastic, asphalt quality, additives, basic characteristics of asphalt, modified asphalt  Abstrak Salah satu cara untuk mengurangi kerusakan struktur perkerasan jalan adalah dengan meningkatkan mutu aspal yang digunakan. Dalam upaya peningkatan mutu aspal dilakukan penambahan bahan aditif, seperti polimer. Penelitian ini bertujuan untuk mengetahui karakteristik dasar aspal modifikasi plastik Low Density Polyethylene, yang meliputi penetrasi, titik lembek, titik nyala dan titik bakar, berat jenis, daktilitas, viskositas. Selain itu, akan ditentukan kadar maksimal plastik Low Density Polyethylene maksimal yang menghasilkan aspal modifikasi yang memenuhi standar Bina Marga. Hasil pengujian menunjukkan bahwa aspal modifikasi dengan plastik Low Density Polyethylene dapat meningkatkan titik lembek aspal serta menurunkan nilai penetrasi, titik nyala dan titik bakar, berat jenis, daktilitas, dan viskositas aspal. Kadar plastik LDPE maksimal yang dapat menghasilkan aspal modifikasi yang memenuhi persyaratan Bina Marga adalah 5%. Kata-kata kunci: plastik, mutu aspal, bahan aditif, karakteristik dasar aspal, aspal modifikasi

No abstract

The casualties in the teenage group in Purbalingga Regency averaged 21.25% of the total accident victims in this area. This relatively large proportion requires efforts through various approaches to reduce the high number of accidents, considering that this group of age is a very important period in people's growth process. This study aims to identify the effect of traffic knowledge on teenage traffic behaviour taking SMK YPT 1 Purbalingga as the case study location. In its analytical process, this research uses descriptive quantitative analysis methods and logistic regression analysis. The output of logistic regression using realstatistic software, identified that the ownership of the driving license provides an opportunity for the occurrence of a bad traffic behaviour. In addition, the better knowledge about signs will provide a role for the possibility of good traffic behaviour. Moreover, the low understanding of road marking gives a probability of bad traffic behaviour. Korban kecelakaan pada kelompok usia remaja di Kabupaten Purbalingga rata-rata sebesar 21,25% dari total korban kecelakaan di daerah ini. Proporsi yang relatif besar ini memerlukan upaya-upaya melalui bermacam pendekatan untuk menekan tingginya angka kecelakaan pada kelompok usia ini, mengingat usia remaja adalah usia yang sangat penting dalam proses tumbuh kembang seseorang. Penelitian ini bertujuan untuk mengidentifikasi pengaruh pengetahuan lalu lintas terhadap perilaku pelaku lalu lintas usia remaja. Dalam prosesnya, penelitian menggunakan metode analisis kuantitatif deskriptif dan analisis regresi logistik. Luaran perhitungan regresi logistik dengan bantuan software realstatistic, diidentifikasi bahwa tidak memiliki SIM memberikan peluang untuk terjadinya perilaku berlalu lintas yang tidak baik. Selain itu, pengetahuan tentang rambu yang semakin baik akan memberikan peranan terhadap kemungkinan perilaku berlalu lintas yang baik. Pada usia remaja, pengetahuan tentang marka yang rendah memberikan probabilitas munculnya perilaku berlalu lintas yang tidak baik.

Abstrak -Di Patikraja Kabupaten Banyumas, terdapat jembatan yang sebelumnya merupakan jembatan kereta api kemudian beralih fungsi menjadi jembatan jalan raya. Kondisi tersebut menyebabkan perubahan pembebanan dan beban gempa. Sehingga perlu dilakukan analisis kinerja jembatan terhadap peraturan yang berlaku. Analisis kinerja jembatan dilakukan menggunakan software SAP 2000 dengan memasukkan data pembebanan jembatan dan beban gempa. Analisis beban gempa menggunakan metode statik ekivalen dan semi dinamik. Analisis mengacu pada SNI T02-2005 mengenai Peraturan Pembebanan untuk Jembatan, dan SNI T03-2005 mengenai Perencanaan Struktur Baja untuk Jembatan, jembatan tersebut mempunyai stress ratio maksimum sebesar 1,575 pada penampang memanjang jembatan, dan angka kelangsingan yang tinggi pada ikatan angin. Dengan nilai stress ratio tersebut material yang digunakan tidak memenuhi standar (stress ratio maksimum adalah 1). Berdasarkan SNI 03-2833-2008 mengenai Standar Perencanaan Ketahanan Gempa untuk Jembatan, waktu getar alami struktur jembatan arah memanjang (arah X) sebesar 1,055 detik pada mode-1 dan arah melintang (arah Y) sebesar 0,875 detik pada mode-2, hal ini menunjukkan beban gempa bergetar pertama pada sumbu X (kondisi mode-1), dan analisis statik jembatan terpenuhi (waktu getar alami tidak melebihi 1,5 detik). Untuk analisis semi dinamik, nilai Celastis diperoleh sebesar 0,521, dimana nilai tersebut tidak melebihi 2,5 kali nilai percepatan dasarnya.Kata kunci: jembatan, jembatan jalan raya, stress ratio, kelangsingan, waktu getar alami.Abstract -In Patikraja Banyumas, there is a bridge that was formerly a railway bridge and then converted into a highway bridge. The condition causes changes in loading and earthquake loads. So the need to analyze the performance of bridges with regulations. Analysis of the performance of the bridge is done using SAP2000 software by entering the data loading and earthquake loads. Analysis of seismic loads using equivalent static and semi-dynamic. The analysis refers to the SNI T02-2005 regarding Loading Regulation for the bridge, and SNI T03-2005 regarding Steel Structures Planning for the bridge, the bridge has a stress ratio of a maximum of 1.575 in longitudinal cross-section of the bridge, and the slenderness ratio are high on the wind ties. With the stress ratio value of the materials used do not meet the standards (maximum stress ratio is 1). Based on SNI 03-2833-2008 regarding Standards for the Earthquake Resistance Planning of Bridge, a natural vibrating bridge structure in the longitudinal direction (the direction X) for 1.055 seconds in mode 1 and the transverse direction (the direction Y) by 0.875 seconds in mode 2, it shows the first vibrating earthquake loads on the X axis (condition-mode 1), and static analysis of the bridge met (naturally vibrate time not exceeding 1.5 seconds). For the analysis of semi-dynamic, Celastis value obtained for 0.521, where the value does not exceed 2.5 times the value of the acceleration essentially.