Analysis of The Rock Fracture on Uniaxial Compressive Strength Test

The compressive strength test is one of the technical properties or compressive strength tests that are commonly used in rock mechanics to determine the collapse point or the elasticity of rock against maximum pressure. The rock collapse point is a measure of the strength of the rock itself when the rock is no longer able to maintain its elastic properties. The purpose of this test is to find out how long the rock maintains its strength or elasticity properties when pressure is applied, and to find out the difference between the strength of compact rock and rock that has fractures when pressure is applied. Rocks that have fractures will break more easily or quickly when pressure is applied compared to compact rocks. This analysis is carried out by comparing the rock strength of each sample, both those that have fractures and compact rocks. To find out these differences, laboratory testing was carried out. The test results show the value (compressive strength test 57.76 MPa), (elastic modulus 5250.000MPa), (Poisson ratio 0.05) and the average value of rock mechanical properties test (axial 0.91), (lateral-0.279), and (volumetric 0.252) . Based on the test results above, it shows that rocks that have fractures will break more easily when pressure is applied, compared to compact rocks that have a long time in the uniaxial compressive strength test.

Slope Stability Analysis Based on Safety Factors on Slope CV. Mutiara Timur in Klampok Village, Tongas District, Probolinggo Regency

CV. Mutiara Timur is a company that is applying for a mining business permit for sirtu commodities in Klampok Village, Tongas District, Probolinggo Regency. The planned mining system is open pit mining using the quarry method. From the results of research in the field obtained rock lithology in the form of topsoil, gravel and sand. Where in the slope design later, the topsoil will be peeled off first. The purpose of slope stability analysis is to determine the geometry of the slope by taking into account the safety factor in order to create safe working conditions. Slope stability analysis on CV. Mutiara Timur using the Bishop method using the Slide v6.0 software. Based on the analysis carried out, the recommendation for slope geometry on a single slope is 4 meters high with a slope of 600 so that the no-load safety factor is 1.350 and the safety factor with load is 1.267. In addition, the slope geometry is obtained on the overall slope, which is a total height of 21 meters with a slope of 380 so that the no-load safety factor is 1.243 and the safety factor with the load is 1.239.

STUDY OF PRODUCTIVITY ANALYSIS OF DIGGING LOADING IN GRAVEL MINING IN PT. GALUH CEMPAKA DISTRICTS CEMPAKA CITY BANJARBARU SOUTH KALIMANTAN PROVINCE

Galuh Cempaka Ltd. is a Gravel Mining Company with an area of 2,994 Ha. The mining system was surface mine or open pit. There are several things which should move in dig and load activities, such as mechanical soil, productivity, and compatibility of loading and conveying equipment are important factors in gravel mining activities. It influences on how far to know the effective work hour and the productivity. The purpose of this research was to determine work efficiency in Galuh Cempaka Ltd, and calculate the productivity of each equipment and the Match Factor value of the loading and conveying equipment in mining activity. From the observation and data processing, it obtained 1 unit of excavator Komatsu PC 400LC, wasingplan as far as 1.5 km. The effective work time was obtained work efficiency of 0.82 and after it was conducted the efficiency become 0.83 and it was reduced the obstacles from excavator CAT 320D. Before digging toll productivity got optimizing from CAT 320D in gravel excavation, it got 94.2 tons/hour and after it got optimizing from CAT 320D excavator in gravel excavation, it obtained 99.6 tons/hours and the IVECO 380 dump truck for gravel loading was 125.55 tons /hour. It obtained Match Factor Overburden (08) < 1. it means it is less than 1. So, there was waiting time for transportation equipment which had not arrived yet. Match Factor Gravel (1.2) > 1 means more than 1. So, there was a waiting time for transportation because the digging tool was filled.

Geological Mapping of Gunungbatu and Surrounding Areas, Bodeh District, Pemalang Regency, Central Java

Mapping is the activity of collecting data from an area to be mapped, in the context of geology mapping means collecting data that includes descriptions of rocks, rock structures, rock positions, structure measurements (plunge/trend, pitch, microfold), rock thickness measurements, rock sampling and sketches. landscape, covering an area to be mapped. Research in the area of Gunungbatu and its surroundings, Bodeh District, Pemalang Regency, Central Java Province with the aim of knowing and knowing that it is in the research area by reconstructing the history of formation or geomorphological history, merely tectonic history in space and time, reconstructing geological history based on micropaleontological analysis. Based on the analysis carried out, it was found that the geomorphological units of the study area were divided into 5, namely the Gunungbatu Syncline Hills Unit, the Kali Bodas Anticline Valley Unit, the Girimulya Syncline Hills Unit, the Cenggiri Homocline Hills Unit and the Kebubung Homocline Valley Unit. The geology of the study area consists of two unofficial rock units in order from oldest to youngest, namely the claystone-sandstone unit and the sandstone-claystone unit. The geological structures of the pinpoint folds and faults are Mount Ketos Syncline, Kali Bodas Anticline, Gapura Syncline, Pertapan Igir Syncline, Cenggiri River Rising Fault, Kebubung Dextral Fault, and Girimulya Dextral Fault. The geological history of the research area begins with the book Unit of Claystone in the Middle Miocene Environment in Upper Bathyal. Furthermore, after the claystone-sandstone units were deposited, during the Middle Miocene – Late Miocene in the Deep Neritic Environment, the sandstone-claystone units were deposited with a turbidite mechanism. As well as the geological resource potential of the research area in the form of river utilization in the form of chunks of igneous rock, river sand deposits and gold seepage. Meanwhile, the potential for geological disasters in the form of landslides.

Productivity Analysis of Raisebore RB-50X for Raise Slot Drilling at Extraction level GBC PT. Freeport Indonesia

PT Freeport Indonesia is the largest gold and copper mine in Indonesia, located in Mimika Regency, Papua Province. In its operation, PT. Freeport Indonesia applies two mining systems, namely open pit mining and underground mining. Underground Mine at PT. Freeport Indonesia consists of DOZ, Big Gosan, DMLZ, Kucing Liar, and GBC, with one of the methods applied by PT. Freeport Indonesia is a block caving method. The Grasberg Block Cave mine has entered the production stage since September 2018, but in its operation the GBC Mine is still developing its operational area to meet production targets (development). The development cycle (cycle development), which is the main operation carried out, namely drilling and blasting, loading & transporting (mucking & hauling), primary support, and secondary support. To support the main operations, it is necessary to have main support consisting of access and area, ventilation, water and water, electricity, pull of tests, surveys, and dewatering. In the blasting process at the drawbell, one free face is needed which functions as the direction of rock collapsing in the blasting process on the drawbell. Making free face or commonly known as slot raise using a rasiebore machine from PT. Redpath for slot raise drilling. Meanwhile, in the drilling stage, the slot raise has a problem that has resulted in delays in the drilling process for the RB-50X raisebore tool. The impact of the delay in making the slot raise resulted in not achieving the production target due to a delay in the blasting process, where the blasting process in the drawbell area functions to break the rock so that it falls and can be transported to the crusher to enter the rock sizing process.

Geological Mapping of the Longkeyang and Surrounding Regions, Bodeh District, Pemalang Regency, Central Java

Geological mapping is one of the important things as part of a field study to obtain geological knowledge. This is due to the need for a geologist who is required to be able to understand the geological conditions of an area, one of which is by conducting mapping activities in the field. In conducting this research activity, it is divided into two stages, namely the field stage and the laboratory stage. The purpose of this research is to determine the characteristics and geological conditions, identify resource potentials and potential geological disasters in the research area. Based on the analysis, it was found that the geomorphological units of the study area were divided into 4 (four), namely the Mount Ketos Homocline Hills Unit, the Polaga River Anticline Valley Unit, the Sarangkadu Cycline Hills Unit, and the Mount Lanji Intrusion Hills Unit. The geology of the study area consists of three rock units in order from oldest to youngest, namely the claystone-sandstone unit and the sandstone-claystone unit and the diorite intrusion unit. The geological structure of the pinnacle area is in the form of folds and faults, namely, Polaga River Anticlines, Sarangkadu Synclines, Polaga River Right Shear Fault, Polaga River Left Shear Fault. The geological history of the study area begins with the deposition of claystone-sandstone units during the Middle Miocene in the Upper Bathyal environment. Furthermore, after the claystone-sandstone units were deposited, during the Middle Miocene – Late Miocene in the Deep Neuritic environment, sandstone-claystone units were deposited with a turbidity deposition mechanism. As well as the geological resource potential of the research area in the form of utilization of river deposits in the form of chunks of igneous rock, river sand deposits and indications of the presence of gold. Meanwhile, the potential for geological disasters in the form of landslides.

The Relation of Fault Fracture Density with the Residual Gravity; case study in Muria

The usages of the FFD analytical method massively are utilized during the last decade, especially in the geothermal preliminary study that can show the prospect reservoir area. This article discusses the correlation of the FFD value with the residual gravity value that is assumed as an indication of the underneath magmatic body. The correlation of FFD value with residual gravity value is applied in Muria mountain. Muria is classified as the volcano body that contains the magmatic body, also exist Genuk volcano and Patiayam hill around Muria. The correlation shows that FFD value and residual gravity value have a relation, but especially for the uninfluenced by structural activity has a low value of FFD. The correlation of FFD and residual gravity is double-checked with the ground truth data, it showing the proof relation. This way of methodology may use for finding the underneath magmatic body, especially applied to the surface that has not been influenced by structural activity.

Resources Estimation on further Exploration activities in PT. Trimegah Bangun Persada (Harita Group) Kawasi Village, South Halmahera District, North Maluku

PT. Trimegah Bangun Persada intends to do mining activity at the north part of IUP as the south and west parts have already been mined. This research aimed at producing natural resources of laterite nickel in the advanced exploration activity of Tangkuban Block. Besides, it also compared and determined the estimation methods having a good correlation with drilling results. Tangkuban Block carried out core drilling within total drill numbers of 286 spots and space distance 25 meters at the block area 22.16 Ha. This research began with determining the geological domain consisting of limonite, saprolite, and bedrock through a geo-statistical approach. After that, the researcher estimated nickel resources by three methods namely ordinary kriging, inverse distance weight, and nearest neighbor point. The result of estimation by ordinary kriging obtained a total volume of limonite layer 1,345,313 m3 with the content average of 1%, while the total volume of saprolite layer was 1,850,000 m3 1.64%.

Application of Vertical Electrical Sounding (VES) Resistivity Method to determine a well recommendation point at deep-groundwater exploitation

The demand of fresh water to develop of life community is very important, where almost all construction activities is required a water such as irrigating rice fields, building infrastructure, and to daily consumption. To obtain a good quality of groundwater, several parameter must be specified such as the depth of groundwater, thickness of the source, and resistivity value of rock. In this case, we try to applied Vertical Electrical Sounding (VES) resistivity method with Schlumberger configuration on one of Pamsimas Project to answer that parameter. VES Resistivity method is one of the active methods in geophysical study based on electrical properties of the subsurface rock by injecting electric current (I) into the earth and record the potential difference (?V) produced to the surface. From the results of current and potential difference measurements for each electrode spacing (AB/2) different then be lowered resistivity variations in the value of each layer below the measuring point (sounding points). After the acquisition on 3 points at Pandansari Village (PS-01, PS-02, PS-03), we get the result on PS-01, the water layer is indicated on the depth 60-80 meters with resistivity values equal than 36.7-50 ?m. On PS-02, the water layer is indicated on the depth 50-100 meters with resistivity values equal than 18.7-40 ?m. On PS-03, the water layer is indicated on the depth 30-60 meters with resistivity values equal than 52.8-70 ?m. Afterthat, we run 2D-pseudosection to know the distribution of groundwater layer in subsurface and get the thickness of groundwater is 20-50 meter with depth 40-80 meter. Based on this result, the PS-01 is the best point to make a well-exploitation on South Pandansari Pamsimas Project.

The Effect of Stress Distribution Around The Decline Shaft on The Support System Stability in Underground Mining

The decline shaft is one of the main facilities in an underground mining work that is used as access to the mining panel from the surface. Making decline shafts on materials with weak characteristics is one of the important geotechnical issues that must be considered. The initial stage of making decline shaft holes is carried out on a relatively shallow ground surface or soil depth so that the horizontal stress that works is greater than the vertical stress. This excavation process will change the direction and magnitude of the initial stress from being in an equilibrium state to being disturbed. In addition to the stress on the rock mass, the condition of weak soil strength will affect the behavior and distribution of stresses working around the decline shaft hole. If the stress around the decline shaft exceeds the strength of the rock, there will be instability in the decline shaft so that strength is needed to control the existing stress.