Identifikasi Potensi Longsor Pada Area Fasilitas Umum Bendungan Jlantah, Kabupaten Karanganyar, Jawa Tengah Menggunakan Metode Mikrotremor

Nabiha, M. Reyhan (2023) Identifikasi Potensi Longsor Pada Area Fasilitas Umum Bendungan Jlantah, Kabupaten Karanganyar, Jawa Tengah Menggunakan Metode Mikrotremor. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 03411940000053-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only until 1 October 2025. Download (13MB) | Request a copy

Abstract

Pembangunan Bendungan Jlantah di Kabupaten Karanganyar Jawa Tengah telah mencapai progres 70%, namun pembangunan konstruksi pada Area Fasilitas umumnya berpotensi untuk terjadi longsor karena lereng – lereng pada area tersebut memiliki tingkat kecuraman yang tinggi dan intensitas hujan pada daerah tersebut juga cukup tinggi. Penelitian ini bertujuan untuk menganalisis potensi longsor pada area fasilitas umum bendungan jlantah karena area ini sedang dilakukan aktivitas ekskavasi dan pembangunan yang mengakibatkan berubahnya susunan lereng dari vegetasi dan geometrinya. Susunan geologi pada area fasilitas umum bendungan jlantah yaitu residual soil yaitu tanah hasil dari pelapukan batuan dan Tuff Lapilli Lapuk, yang menandakan area ini mempunyai kestabilan tanah yang rendah. Metode yang digunakan dalam penelitian ini adalah metode mikrotremor, metode ini menghasilkan arah particle motion dan berbagai parameter seperti frekuensi dominan (f_0), faktor amplitudo (A_0), periode dominan tanah (T), Peak Ground Acceleration (PGA), dan Average Shear Strain (ASS). Hasil yang didapatkan dari adalah penelitian ini persebaran arah particle motion pada area fasilitas umum bendungan jlantah didominasi oleh arah North West – South East dan North East – South West, persebaran nilai frekuensi dominan pada area fasilitas umum bendungan jlantah didominasi oleh nilai < 2,5 Hz dan 2,5 – 4 Hz, persebaran nilai faktor amplitudo pada seluruh area fasilitas umum diklasifikasikan sebagai amplitudo sedang dengan nilai 3-6, persebaran nilai periode dominan pada area fasilitas umum didominasi oleh nilai 0,25 – 0,4 s, persebaran nilai peak ground acceleration pada area fasilitas umum bendungan jlantah didominasi oleh nilai 200 – 300 gal, Persebaran nilai Average Shear Strain pada seluruh area fasilitas umum bernilai 10^(-3) - 10^(-4), dan kondisi geologi dengan kemiringan lereng pada area fasilitas umum, mempunyai kecuraman 25 – 45% dan > 45%. Hasil parameter – parameter tersebut digabungkan dengan metode skoring dan pembobotan, lalu menghasilkan blok – blok/zonasi tingkat kerawanan longsor yang perlu diperhatikan oleh stakeholder terkait upaya mititigasi peristiwa longsor agar aktivitas pembangunan dan aktivitas warga tidak terganggu apabila terjadi longsor dikemudian hari.
=================================================================================================================================
The construction of the Jlantah Dam in Karanganyar Regency, Central Java, has reached 70% progress, but construction construction in the Facility Area generally has the potential for landslides because the slopes in the area have a high level of steepness and the intensity of rain in the area is also quite high. This research aims to analyze the potential for landslides in the public facility area of Jlantah Dam due to ongoing excavation and construction activities, which have altered the slope's vegetation and geometry. The geological composition in the Jlantah Dam public facility area consists of residual soil, which is soil resulting from rock weathering, and Weathered Tuff Lapilli, indicating low soil stability in the area. The method used in this research is the microtremor method, which provides information on particle motion direction and various parameters such as dominant frequency (f0), amplitude factor (A0), dominant soil period (T), Peak Ground Acceleration (PGA), and Average Shear Strain (ASS). The findings of this study reveal that the distribution of particle motion direction in the Jlantah Dam public facility area is predominantly in the North West – South East and North East – South West directions. The distribution of dominant frequency values is mainly below 2.5 Hz and between 2.5 and 4 Hz. The distribution of amplitude factor values in the entire public facility area is classified as moderate, with values ranging from 3-6. The distribution of dominant period values in the public facility area is mainly between 0.25 and 0.4 seconds. The distribution of peak ground acceleration values in the Jlantah Dam public facility area is dominated by values between 200 and 300 gal. The distribution of Average Shear Strain values throughout the public facility area ranges from 10−3 - 10−4 . The geological conditions, along with the slope inclinations in the public facility area, exhibit gradients of 25-45% and >45%. By combining these parameter results using scoring and weighting methods, the research produces blocks/zoning representing the susceptibility levels of landslides that stakeholders should consider for mitigation efforts. These measures aim to prevent disruptions to construction activities and the community in the event of future landslides.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Mikrotremor, Longsor, Particle Motion, Horizontal to Vertical Spectral Ratio, Microtremor, Lanslides
Subjects:	H Social Sciences > HV Social pathology. Social and public welfare > HV551.5.I4 Hazard mitigation Q Science > QE Geology Q Science > QE Geology > QE538.8 Earthquakes. Seismology Q Science > QE Geology > QE599 Landslides. Rockslides T Technology > T Technology (General) > T57.5 Data Processing
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geophysics Engineering > 33201-(S1) Undergraduate Thesis
Depositing User:	M. Reyhan Nabiha
Date Deposited:	09 Oct 2023 00:59
Last Modified:	09 Oct 2023 00:59
URI:	http://repository.its.ac.id/id/eprint/103967

Actions (login required)

View Item