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This study examines the reclamation plan of PT. Z for the 2023–2027 period with the aim of assessing the technical feasibility, ecological effectiveness, and alignment with national reclamation regulations. A descriptive-quantitative approach was employed through field observations, analysis of geomorphological conditions, evaluation of topsoil management, assessment of revegetation performance, and review of key environmental documents. The planned land disturbance reaches 138.53 ha, with reclamation focused on the disposal and topsoil areas covering 29.67 ha, as the mining pit remains active. Reclamation activities include land recontouring, topsoil spreading, erosion control, establishment of Legume Cover Crops (LCC), and planting of local species such as Rukam. The results indicate that the implemented strategies effectively enhance soil stability, improve vegetation cover, and support ecosystem recovery. Furthermore, the reclamation program meets the key performance criteria set by the Ministry of Energy and Mineral Resources, with vegetation cover exceeding 90% and stable slope conditions. Challenges remain, particularly related to sedimentation management and the absence of pit reclamation during the active mining phase. Overall, the study concludes that PT. Z has developed and executed a reclamation plan that reflects good mining practices and environmental stewardship, contributing to the long-term sustainability of post-mining land use.

Shrub vegetation is an important component in the structure of vegetation communities that have a significant ecological role, especially in maintaining soil stability and supporting biodiversity. One area that has the potential for shrub vegetation diversity but has not been scientifically documented is the Jaboi hot spring area, Weh Island, Sukajaya District, Sabang City. The purpose of this study was to investigate various types of shrub vegetation found in the study area and to calculate the diversity index. Data collection was carried out using a one-hundred-meter line transect method divided into four paths, with one pair of transects directed towards residential areas and plantation areas, while the remaining two transects were directed towards areas that were still forested. At each transect there were six observation points with a distance between points of 20 meters, each point consisting of three quadrat plots measuring 2 × 2 meters. Analysis of the diversity index used the Shannon-Wiener formula (H’). The results showed that there were 9 shrub species from 7 families with a total of 169 individuals from four observation stations. The Melastomataceae family dominates the shrub community with two main species, Melastoma malabathricum and Memecylon caeruleum. The diversity index value is 2.17, which is included in the moderate category (H = 2–3). This diversity is influenced by the physical-chemical conditions of the environment, such as acidic soil pH (4.4–5.5) and relatively stable temperatures, although temperatures exceeding the optimum limit were found in some locations. This study provides initial data on the potential of shrub vegetation as a basis for ecosystem management and conservation in the area.

Clay soil stabilization is a crucial process to enhance the soil's bearing capacity and stability, making it more suitable for construction purposes. Stabilizing clay soils improves their mechanical properties, reduces swelling, and increases their load-bearing capacity, which is essential for the foundation of various structures. This study aims to investigate the effect of lime (CaO) addition and curing time on the physical properties of clay soil, particularly focusing on unconfined compressive strength (qu) and overall soil stability. The experimental methodology involved applying different percentages of lime content (ranging from 3% to 7%) and varying curing times (7, 14, and 28 days). The soil samples were tested for their unconfined compressive strength after each combination of lime content and curing duration. The results indicated that the addition of 5% lime (CaO) and curing for 14 days led to a significant improvement in the unconfined compressive strength by 153.3%, compared to the untreated clay soil. Furthermore, increasing the curing time beyond 14 days did not show substantial improvements in strength, suggesting that 14 days is the optimal curing period for this combination. The study also highlighted that the lime treatment not only enhanced the mechanical properties but also reduced the plasticity of the clay, making it more stable and easier to handle during construction. Based on these findings, it can be concluded that the appropriate combination of lime content and curing time plays a significant role in improving the stability of clay soils. This research provides valuable insights into optimizing soil stabilization techniques, offering an effective solution for enhancing soil properties for engineering applications

Stabilisasi tanah merupakan upaya memperbaiki tanah dalam keadaan tertentu sehingga didapatkan karakteristik tanah yang diinginkan dengan menambah zat aditif untuk meningkatkan kekuatan tanah. Tujuan penelitian ini untuk mengetahui sifat fisis dan mekanis tanah asli, mengetahui pengaruh bahan stabilisasi tambahan terhadap tanah, dan perbandingan pada campuran optimal. Penelitian ini menggunakan bahan semen PCC dan semen instan. Metode yang digunakan dalam penelitian ini yaitu pengujian laboratorium dengan uji kuat tekan bebas (UCT) dengan masing masing bahan aditif menggunakan komposisi campuran 0%,4%,8% dan 12%. Berdasarkan pengujian sifat fisis tanah asli memperoleh nilai berat jenis rata rata 2,595, (γb) 1,637 gr/cm³, dan termasuk jenis tanah lempung organik dengan plastisitas sedang sampai tinggi (OH). Berdasarkan sifat mekanis diperoleh dengan uji UCT tanah asli memiliki nilai kuat tekan bebas 0,677 kg/cm2 dengan Cu yaitu 0,338 kg/cm2. Untuk kuat tekan bebas tanah asli dan semen PCC paling tinggi didapat 1,776 kg/cm2 pada komposisi bahan stabilisasi semen PCC sebesar 8%, dan kuat tekan tanah asli dan semen instan paling tinggi didapat sebesar 1,967 kg/cm2 pada campuran semen instan 8%. Berdasarkan penelitian dapat disimpukan bahan paling optimal yaitu semen instan dengan komposisi campuran 8%. Perbandingan kuat tekan bebas dari tanah asli dibandingkan dengan semen PCC dan semen instan yaitu 0,677; 1,776;1,967.