Assessment of physicochemical parameters for the drinking water quality in the vicinity of Nawabshah City, Sindh, Pakistan

Quality of water may differ according to the geography of the region, due to that the quality of water is big concern worldwide, because majority of disease caused by the poor quality of drinking water. Subsequently realizing the significance of drinking water quality with in the central part of the Sindh province, this research work was carried out to assess the drinking water quality within the Nawabshah city, where the single source of supply water is the Gajrawah after the conventional treatment through the open ponds. In this study seven physicochemical parameter were investigated and laboratorial investigations demonstrated that the pH values were found with the WHO limits, TDS & EC values were found within the acceptable limits, except in one residential area, Turbidity was also high at all the locations only one area (Marium road colony) was found within the standards, furthermore, the hardness was present in all the samples at all the locations, which indicate that the water supplied to public was hard in nature. In addition to that Temperature and Dissolved Oxygen were found safe and within the limits and it was concluded that the water supplied to residents of the inspected areas were found not fit for drinking and it is suggested that the water supply, should be improved and essential steps should be taken to treat the water

Effectiveness of coffee husk ash and coconut fiber in improving peat properties

Peat is a well-known problematic soil associated with poor engineering properties because its engineering with low shear strength, highly compressible, high moisture content. The characteristics make it unsuitable for construction in its natural stage. Thus, this study determines the soil properties of untreated peat soil and assesses the changes in strength of the treated peat soil using the admixture of Coffee Husk Ash (CHA) and Coconut Fibre (CF). The percentage of CF used is 0.50%, 0.75% and 1.0% meanwhile the percentage of CHA used was 5%, 6%, and 7% by the weight of the soil sample. The peat soil for this study were retrieved from Mardi Pontian in Johor. Soil properties such as moisture content, bulk density, and the Atterberg limit have been tested. The result of the Standard Proctor test in this study determined the Optimum Moisture Content and Maximum Dry Density of soil samples. The strength of these samples has been determined by using the Unconfined Compressive Strength (UCS). The physical properties for untreated peat soil with the moisture content of 250%, organic content about 77%, the specific gravity was in the range of 1.48–1.8. The Atterberg limit for liquid limit is 230. The compaction test results has shown decrement in maximum dry density (MDD) but an increase in strength with the addition of CHA and CF in peat soil. According to the findings, 0.5% of Coconut Fiber improves the engineering properties of peat soil (CF)

Effect of moisture content on significant parameters to the surface excavation performances

The influence of moisture content on weathered rock arise frequent issues related to excavation works. It should be taken into consideration as unique features in tropical climate. Therefore, the need for an effective assessment on excavation works related to the moisture content is demanding. A systematic approach of field and laboratory assessments were structured with geological data collection and field trials at Sedenak, Bentong and Ulu Kinta sites. First, the field study includes geological mapping and discontinuity survey in order to characterize the weathering state, followed by thirty-six excavation trials were carried out during sunny day and after rainy days. Then, the physical properties of rock materials were determined by laboratory works including point load test, jar slake, moisture content, slake durability and petrographic analysis on forty rock samples of sandstone, shale and granite respectively. Rock masses recorded joint spacing of 0.1-2 m with maximum of four joint sets during field investigation. Sandstone and shale exhibit bedding as major type of discontinuity as compared to granitic rock which only characterized by the joints and faults. Block size shows a decreasing trend, ranges from 1-0.1 m3 with weathering degree of slightly to completely weathered. From petrographic study, it is revealed that percentage of clay in slightly weathered in sandstone, shale and granite is 2.1%, 2.7% and 0% respectively. Meanwhile, the percentage of clay in moderately weathered is found to be 36%, 45% and 10% for the similar rock types. Clay content increase in the highly weathered state with 49%, 55% and 75%. Furthermore, for completely weathering state, sandstone and shale consist of 95% of clay and granite is 90%. The incremental of clay content has been found as one of the major factors in reducing the rock material strength. It was established that reduction strength of slightly weathered sandstone and granite ranges from 5-12% and 8-10% respectively. Whereas, in moderately weathered sandstone reduced 16-20%, while in granite is 33% to 37%. The strength reduction become more significant in highly weathering state which ranges from 50-60% in sandstone and shale, while 50-57% for granite. The result shows that the block size more than 0.6 m3 could not be excavated. The case was different when it involves block size ranges from 0.15-0.5 m3 with productivity less than 15 m3/h for all type of rock for slightly weathered rock mass. In highly weathering state, block size which ranges from 0.1-0.8 m3 resulting the productivity increase between 10-45 m3/h. The case is different in completely weathered, where block size ranges 0.1-0.8 m3 does not influenced much on the productivity resulting 25-50 m3/h. It was found that increment of moisture content help to increase the productivity when the block size measured less than 0.3 m3 for all types of rocks. The productivity increased by 20-50% when excavated after heavy rain on moderately and highly weathered sandstone and shale. This study prove that moisture content could affects the performance of excavation significantly on highly weathered rock mass. The effects are minimal for completely weathered, slightly weathered and moderately weathered rock masses. The block size does not become important factor in controlling the excavation performance in the slightly and completely weathered zone

Assessment parameters of rock masses for excavation in relation to moisture content

The influence of moisture content on weathered rock arise frequent issues to the excavation works. A systematic approach of field and laboratory assessments were structured with geological data collection and excavation trial at two sites which Bentong site consist of sandstone and shale while Ulu Kinta site is characterized by granite to propose suitable assessment parameters of rock mass for excavation in relation to moisture content. Field study includes geological mapping and discontinuity survey in order to characterize the weathering state. Thirty-six trial tests were carried out during sunny days and after rainy days. Fourteen trials on sandstone and shale respectively and eight for granite. From field study, joint spacing are 0.1–2 m with maximum of four joint sets. Block size shows decreasing trend ranges from 1–0.1 m3 is slightly weathered to completely weathered rock mass. The result showed that block size more than 0.6 m3 could not be excavated. When involves block size ranges from 0.15–0.5 m3, the productivity less than 15 m3/h for all type of rock for slightly weathered rock mass. In highly weathered, block size ranges from 0.1–0.8 m3, productivity increase between 10–45 m3/h. Block size ranges 0.1–0.8 m3 does not influenced much on the productivity of completely weathered resulting 25–50 m3/h. It was found that increment of moisture content help to increase the productivity when the block size measured less than 0.3 m3 for all types of rocks. The productivity increased by 20–50% when excavated after heavy rain on moderately and highly weathered sandstone and shale. This study prove that moisture content could affects the excavation performance significantly on highly weathered rock mass. The effects are minimal on slightly, moderately and completely weathered rock mass. The block size does not become important factor in controlling the excavation performance in the completely and slightly weathered rock

Rockmass classification of tropically weathered karst limestone of Cambodia for blastability

In civil and mining projects, blasting may be necessary for breaking rocks prior to excavation. Due to tectonic activities faulting and folding in rockmass takes place resulting change in physical and mechanical properties of rock. Rocks are further exposed to weathering which affect geomechanical properties of rockmass. Thus, rockmass has different geomechanical and varied physical properties in the same rockmass. Practicing civil and mining engineers should be able to visualize rockmass in the field to get desired blasting results. Rockmass is heterogeneous material having varied geo-mechanical properties which affect blast fragmentation. Due to geological discontinuities such as faults, folds there can be environmental effect such as fly rock and ground vibration which need to be controlled as there may be local community. This research study is for developing rockmass assessment system for karst limestone in Cambodia which will be useful for design of blast with commons known parameters used by field engineers so that desired result of fragmentation can be obtained. Further this rockmass assessment system will be practical to minimize the effect of fly rock hazard and ground vibration due to blasting. Limestone in Cambodia is explored and initial stage of development. Blastability index (BI) will be compared to recent approaches and these parameters will be considered for rockmass assessment. During initial stage of mining project, detailed information on limestone deposit may not be available. The proposed methodology of rockmass assessment is based on review and will be useful for blast design and prediction of blast performance in Cambodian limestone deposit. Karst limestone in Cambodia is classified into five classes based on exploration data consisting of RQD, degree of weathering, degree of hardness and percentage cavities based on exploration data. Major cavities observed are in cherty limestone and argillaceous limestone. 65% cavities are filled with clay and 35% cavities are not filled with any material. Further exploration data is classified based on block model based on structures identified, hardness of rock and will be useful for co-relating with blastability index. 99% of cavities in karst limestone are found with argillaceous and upper cherty limestone. Based on cavity classification, 74% drilling area has average cavities of 0.37% which is least. 9% of drilling area has >20% of cavities or 2% of total area which is highest and concern for blast performance from fly rock, fragmentation and back break point of view

Fracture characterization using downhole camera in deep boreholes at Southern Johor Bahru, Malaysia

Downhole camera is an effective tool to locate fractures and other geological features in boreholes although it does not quantify the characteristics of fracture directly. This study attempts to qualitatively characterize fractures in three deep boreholes, namely W1-W3 using downhole camera of R-CAM 1000 XLT as well as to investigate the geological features present at Southern Johor Bahru. The study area is underlain by Jurong Formation and Older Alluvium. Jurong Formation comprises of well cemented and consolidated volcanic-sedimentary rocks while Older Alluvium comprises of coarse, angular clayey sand with pebbles such as quartz, rhyolite, chert and argillite pebbles. The geological features encountered during the study are brecciated zone and veins such as quartz, calcite and pyrite. In addition, the fracture density in W2 (175/150 m) is found to be higher than W1 (79/165 m). Gently dipped (<20°), single set of joints with tight to open aperture (<0.1–4 cm) are dominant in both wells. Major orientation of discontinuities is north-east (0–90°) to south-west (180–270°) which is subparallel to bedding plane and lineament orientations. Meanwhile, no major structure is observed in W3. Thus, the study shows the importance of downhole camera survey in locating and characterizing fractures in rock mass qualitatively

Permodelan keupayaan tenaga serapan bagi tiub pelindung laga menggunakan kaedah unsur terhingga

Kajian ini dijalankan untuk mengkaji prestasi penyerap tenaga dan kelakuan runtuhan pada pelindung laga apabila berlaku perlanggaran. Pelindung laga dapat mengurangkan tahap kecederaan kepada pemandu dan penumpang kenderaan semasa berlaku kemalangan. Berdasarkan kepada kajian lepas, kebanyakkan perbincangan dijalankan adalah dalam mampatan sepaksi. Namun, mampatan sipi kurang dibincangkan. Pada masa yang sama, kurang kajian pada tiub hibrid dalam struktur pelindung laga. Model simulasi tiub pelindung laga dibina dengan menggunakan unsur terhingga ANSYS/LS-DYNA dengan mampatan kuasi-statik. Tiub pelindung laga menggunakan keluli berketahanan tinggi sebagai lapisan dalam dan bahan komposit pada lapisan luar. Bahan komposit yang digunakan adalah e-kaca/epoksi dan karbon/epoksi. Perubahan mampatan nisbah sipi yang digunakan adalah 0.00, 0.25, 0.50 dan 0.75. Perubahan sudut susunan komposit yang terlibat adalah [+30º/-30º/+30º], [+45º/-45º/+45º] dan [+60º/-60º/+60º] dengan ketebalan lapisan 0.5, 0.8 dan 1.0 mm. Manakala, perubahan nisbah elips yang digunakan pada tiub keluli adalah 0.5, 0.7, 1.0, 1.3 dan 1.5. Selain itu, jenis sentuhan algoritma yang digunakan adalah "automatic surface to surface contact", "contact automatic single surface", "contact eroding single surface" dan "contact tiebreak surface to surface" pada jasad tegar, tiub keluli dan lapisan komposit. Kesan perubahan ketebalan, jenis dan sudut susunan lapisan komposit terhadap prestasi tenaga serapan dan kelakuan runtuhan beransur dipertimbangkan dalam kajian. Kajian ini menunjukkan tiub hibrid menghasilkan prestasi tenaga serapan yang lebih baik berbanding tiub keluli kosong. Selain itu, didapati jenis komposit karbon/epoksi menghasilkan keputusan yang lebih baik berbanding dengan komposit e-kaca/epoksi terhadap prestasi penyerapan tenaga