Borehole Method Research Articles

Seismic response of deep soft soil sites with varying shear wave velocities

The variations in seismic response between deep soft soil sites with different shear wave velocities were not fully understood. This study focuses on the seismic response of deep soft soil sites in the lower reaches of the Yangtze River, China. A nonlinear dynamic finite element model was developed for two representative deep soft soil sites with borehole profiles and the shear wave velocity tested by the single borehole method. Two nonlinear cyclic constitutive models are used and thus compared through the site seismic response. To accurately calibrate the nonlinear cyclic model parameters, resonant column tests were conducted on 21 soil samples collected from the two boreholes. The results show that the peak ground acceleration (PGA) under low-frequency (Liuan) input motion was higher for soft soil sites compared to that under medium- and high-frequency (Kobe and Nahanni) input motions. The PGA amplification factor for deep soft soil sites under different input motions can be approximated by an exponential function. The peak ground acceleration tends to be lower as the equivalent shear wave velocity (Vse) decreases. The shapes of the spectral acceleration were similar for the two sites, despite a substantial difference in the Vse between them. Additionally, a crossover point was observed in the spectral acceleration for the two sites. The period corresponding to this crossover point increased with increasing intensity of input motions, indicating that the sites became softer with higher intensity and thus generally exhibited a longer characteristic period of the spectral acceleration. This paper also highlights the significance of selecting nonlinear constitutive models and the precise calibration of model parameters in the seismic response analysis of deep soft soil sites, providing a scientific basis for future similar site analyses.

The Impact of Waste Application on the Reclamation and Biological Life of Degraded Soils

This work concerns the assessment of soil reclamation and its impact on biological life in areas destroyed by the sulfur industry in Jeziórko. Sulfur extraction using the borehole method causes enormous destruction to the soil environment. Among the many forms of degradation, the most pronounced are the chemical transformations of the environment and the disturbances in water relations in large areas, which could theoretically impact areas not within the direct range of the mining plant. This work aimed to assess the condition of biological life in soil reclaimed with waste in areas devastated by the sulfur industry in Jeziórko. The reclamation of these soils was difficult but necessary due to the complete disappearance of biological life. Appropriate actions were taken to restore and improve the properties of the soil, which resulted in an improvement in their production capacity. Reclamation was carried out, among other techniques, by deacidifying the soil using post-flotation lime and fertilizing the soil with municipal sewage sludge and post-use mineral wool. Studies have shown an improvement in many soil properties, such as its physical, water, chemical, and biological properties. The implemented reclamation methods significantly influenced, among other things, the density and water properties of the degraded soil. The soil reclaimed with mineral wool and sewage sludge recorded the highest density and water capacity. Applying mineral wool to the degraded soil influenced the changes in the analyzed physical and water properties. The obtained research results also show the beneficial effect of mineral wool and sewage sludge on the increase in organic carbon content. In the soil treated with these substances, the organic carbon content ranged from 13.60 g·kg−1 to 14.30 g·kg−1. It is shown that reclamation has had a considerable impact on and is essential for biological life in Jeziórko.

Development of an in situ alloying method for high-performance welding processes to achieve an LTT effect by local modification of the alloy content

One possible option for increasing the fatigue strength of welded joints is the use of so-called low transformation temperature (LTT) alloys. The aim is to introduce residual compressive stresses into the weld to counteract crack initiation and propagation. Until now, there has been no application of an LTT effect to high-performance welding processes such as the laser beam submerged arc hybrid welding process (LUPuS hybrid). First, the LUPuS hybrid single-wire process was further developed into the LUPuS tandem hybrid process. This makes it possible to equip the two submerged arc welding torches with different commercially available filler wires. The aim of the work is to further develop the LUPuS tandem hybrid welding process to enable the use of the LTT effect. The in situ alloying process for obtaining the LTT effect from commercially available material combinations was extended to the two-wire process. The alloy obtained was investigated by means of energy dispersive x-ray spectroscopy and hardness measurements and the influence on residual stresses was determined by the borehole method supported by electronic speckle pattern interferometry.

Embedded Wireless Sensor for In Situ Concrete Internal Relative Humidity Monitoring.

The moisture content within the concrete pore network significantly influences the mechanical, thermal, and durability characteristics of concrete structures. This paper introduces a novel fully embedded wireless temperature and relative humidity sensor connected to an automatic acquisition system designed for continuous concrete monitoring. Relative humidity measurements from this new sensor are compared with those obtained by a commercial system based on the borehole method at different depths (2.5 and 4.0 cm) and exposure conditions (oven drying and humid chamber). The results allow for proving that both systems provide consistent internal relative humidity measurements aligned with the exposure conditions and highlight the capability of fully embedded wireless sensors as a practical and reliable alternative to the conventional borehole method. Additionally, the continuous monitoring of the wireless cast-in sensor exhibits reliability during unintended temperature fluctuations, emphasizing the effectiveness of permanently installed sensors in promptly detecting unintended curing variations in real time. The continuous real-time information provided combined with the practicality of these sensors might assist construction managers to improve the quality control of the concrete curing process and shrinkage behavior, and ensure the integrity of concrete surface finishing.

A 3D Numerical Model for Improving Methane Drainage Efficiency in Underground Coal Mines Using the Cross‐Measure Borehole Method

The release of methane into the working area of coal mines can affect safety and production. Therefore, methane drainage reduces the risk of explosion and can be used as a fuel and energy source. One methane drainage method is cross‐measure borehole drilling, which involves drilling boreholes from tailgate roadways to the roof or floor layers of a mined seam. In this method, determining the appropriate distance between methane drainage stations has a significant impact on increasing the efficiency of operation and reducing drilling costs and the time required for drainage operations from each station. In this paper, a new 3D numerical model is developed for methane drainage from an underground coal mine to determine the suitable distance between methane drainage stations in the cross‐measure borehole method using COMSOL Multiphysics software. For this purpose, by considering the porous media flow module and the laws related to the movement of gas in the goaf, different numerical models for distances of 10, 15, 20, 25, and 30 m were simulated. The simulation results showed that by reducing the distance between methane drainage stations, the speed of gas flow in the borehole and the amount of gas removed from the boreholes in a similar period of time increase to an acceptable level. In addition, the implementation of this model in a case study showed that a distance of 10 m between drainage stations increases the efficiency of boreholes to approximately 20%. Numerical simulation in this study can provide basic support for the design of drainage boreholes and reduce the risk of gas in underground coal mines.

Temporal and spatial variability of physical and chemical properties in reclaimed soil after sulphur borehole mining

Mining contributes to the creation of degraded areas that are difficult to rehabilitate because they are subject to various transformations. Specifically, sulphur mining using the Frasch borehole method causes multidirectional changes of soil properties and thus presents challenges for post-mining rehabilitation. The aim of the current study was to evaluate the effectiveness of agricultural (meadow-type) reclamation and to understand how the soil recovers over time by assessing the spatio-temporal variability of the reclaimed soil after borehole sulphur mining. Selected soil properties and spectral indices based on satellite data were analysed: before reclamation, 3 years after reclamation and 15 years after reclamation. Texture, bulk density, porosity, water capacity, total organic carbon (TOC) and pH were measured and distribution maps of these parameters were generated using kriging. Additionally, maps of spectral indices (Green Normalized Difference Vegetation Index, Normalized Difference Soil Moisture Index, Soil Adjusted Vegetation Index, Enhanced Vegetation Index and Red–Green Index) based on Landsat imagery were created to support the field survey data. The soil revealed high temporal and spatial variability, as evidenced by the distributions of measured parameters and their coefficients of variation at different reclamation stages. Multidirectional remodelling of the soil structure occurred, resulting in changes in the differential porosity, field water capacity, texture, reaction and TOC. Statistically confirmed differences in soil parameters between sampling points were observed. The variability of the physical and chemical parameters at the individual sampling point also differed between the reclamation stages. We observed a general trend towards homogenisation of the spatial distributions of the soil parameters. This was also confirmed by the maps of spectral indices, which showed establishment and development of a continuous vegetation cover and the subsequent improvement of its condition.

Numerical simulation of welding residual stress in Incoloy 825/L360QS bimetal clad tube

With severe corrosion issues afflicting nearly half of all high sulfur gas fields, bimetal composite tubes have emerged as an optimal solution due to their superior corrosion resistance, mechanical properties, and cost-effectiveness. These tubes have gained widespread adoption in gas gathering applications. However, the evaluation of the corrosion performance of Incoloy 825 bimetal composite tubes within high sulfur gas field environments is yet to be adequately addressed. An investigation into the welding performance of both the base metal and weld is instrumental in ascertaining the safety and reliability of bimetal composite pipes. To this end, this paper presents a thermodynamically coupled finite element model of bimetal composite pipes, developed using SYSWELD software, and corroborates the model using the borehole method for empirical verification. The study further delineates the distribution of residual stress encountered during multi-layer and multi-pass welding of bimetal composite pipes.

Characteristics and Quality Assessment of Oleoresin Production through Bore-hole Method in Chir-pine Under Narendranagar Forest Division, Uttarakhand, India

The present study aimed to evaluate the Oleoresin quality in Chir-pine. It was observed that the main compounds of Chir-pine’s Oleoresin were Rosin, α and β-pinene with the highest percentage and are considered products with high commercial value. There was significant variation recorded while testing the quality of Oleoresin in Chir-pine. Oleoresin obtained from the Bore-hole method was found to be pure as compared to the traditional Rill method. The content of Rosin, α - Pinene, β - Pinene, Carene, and Turpentine oil was in good quality in Bore-hole method. It was further observed that in 1 Kg of Oleoresin, about 70.00 -72.20 % of Rosin was obtained in Rill method whereas in Bore-hole method, approximately 74.10 % of Rosin. On the other hand, α – Pinene, β – Pinene was significantly recorded with 20.80 and 03.40 in Bore-hole method as compared to the three year data of Rill method which showed the purity of the Oleoresin in Bore-hole method. So, the present study recorded that best quality of Oleoresin in Bore-hole method as compared to the Rill method.

Dry Parallel Seismic: A Novel Method for Determining Thickness of Buried Concrete Pad Foundations

The structural capacity of concrete foundations supporting, for example, telecommunications and electrical transmission towers depends, among other things, upon the thickness of the concrete foundation. Current methodology for investigating the thickness of concrete foundations nondestructively has largely been focused upon deep foundations, such as caissons, and in situations where the top of the foundation is exposed. For example, the parallel seismic (PS) method is a borehole method that uses the arrival times of waves imparted in a foundation at a sensor next to a buried foundation to detect the thickness of the foundation but is typically used for deep caisson type foundations. However, in many instances, these foundations are pad and pier type footings that can be buried deep below ground and can be relatively thin, for example, less than 45 cm in thickness. The objective of the present work is to present a nondestructive method for determining the thickness of concrete pads with no direct access. The dry PS method was developed to determine the thickness of thin, buried concrete foundations. The method was first used to verify the as-built thickness, as mentioned in the engineering drawings of a guyed tower dead-man block. Second, it was used to determine the thickness of the pad foundations of five telecommunication towers with pad and pier concrete foundations in South Asia. These towers had foundation thicknesses ranging from 16 to 36 cm, as verified through excavation. Analysis of the data collected during dry PS testing resulted in a mean absolute error (MAE) of 18 mm, which equates to approximately 6% error. Thus, this paper demonstrates that the dry PS method overcomes the limitations of the current methodology and is capable of accurately determining the thickness of buried concrete foundations.

Production and Cost of Chir-Pine Resin Tapping by Bore-Hole Method in Narendranagar Forest Division

Production and Cost of Chir-Pine Resin Tapping by Bore-Hole Method in Narendranagar Forest Division

Efficacy of Oleoresin obtained from Bore-Hole Method in Chir-Pine for Potential Antimicrobial Activity

Efficacy of Oleoresin obtained from Bore-Hole Method in Chir-Pine for Potential Antimicrobial Activity

Determination of suitable distance between methane drainage stations in Tabas mechanized coal mine (Iran) based on theoretical calculations and field investigation

A large amount of gas is emitted during underground mining processes, so mining productivity decreases and safety risks increase. Efficient methane drainage from the coal seam and surrounding rocks in underground mines not only improves safety but also leads to higher productivity. Methane drainage must be performed when the ventilation air cannot dilute the methane emissions in the mine to a level below the allowed limits. The cross-measure borehole method is one of the methane drainage methods that involves drilling boreholes from the tailgate roadway to an un-stressed zone in the roof or floor stratum of a mined seam. This is the main method used in Tabas coal mine N 1. One of the effective parameters in this method is the distance between methane drainage stations, which has a direct effect on the length of boreholes required for drainage. This study was based on the measurement of ventilation air methane by methane sensors and anemometers placed at the longwall panel as well as measuring the amount of methane drainage. Moreover, in this study, the obtained and analyzed data were used to determine the suitable distance between methane drainage stations based on the cross-measure borehole method. In a field test, three borehole arrangements with different station distances in Panel E4 of Tabas coal mine N 1 were investigated. Then, the amounts of gas drained from these arrangements were compared with each other. The highest methane drainage efficiency was achieved for distances in the range of 9-12 m between methane drainage stations.

Study on gas extraction efficiency using in-seam borehole method considering influence of plastic zone induced by borehole drilling

Gas hazards pose a serious threat to the safety of coalmines. Gas extraction through in-seam boreholes is an important technical approach for preventing gas hazards and achieving rational exploitation of gas as a clean resource. Improper extraction design may result in inefficient gas extraction and create the risk of gas emission overrun, or even coal and gas burst during mining process. Gas extraction efficiency is associated with the permeability of the coal seam, which is affected by the integrity and porosity of the coal seam. The change in permeability in plastic zones induced by borehole drilling or roadway excavation is usually not sufficiently considered when designing a gas extraction scheme and predicting the gas extraction efficiency. In view of this, this research investigated gas extraction efficiency using in-seam borehole method considering influence of drilling/excavation induced plastic zone. Based on a gas extraction project in the Huainan mining area of China, site measurements were performed to test the pressure distribution characteristics along the gas extraction pipe. Subsequently, the radius of the plastic zone around the borehole was deduced based on elastic–plastic theory. Furthermore, a gas flow equation under extraction conditions was proposed, and the apparent permeability of the coal seam was analyzed by considering the plastic deformation induced by roadway excavation and borehole drilling. Finally, a three-dimensional model was built, and the gas flow performance was simulated by considering the influence of the plastic zone. The calculated radius of the plastic zone was compared with the analytical results. The evolution characteristics of the gas pressure and the effective extraction radius were obtained. In addition, optimized measures for the design of extraction boreholes are proposed.

Alluvial tin mining by spray-suction borehole method: a case study on remaining alluvial tin reserves in Bangka Belitung, Indonesia

The area of the Bangka Belitung Islands, which is a potential area for alluvial tin deposits in Indonesia, has been affected by the destruction of tin reserves on the mainland due to rampant artisanal mining, which has left remnants of small-dimensional reserves. The remnants of these reserves can no longer be mined using the hydraulic mining of open pit method due to the small dimensions of the deposits. The hypothesis is that such sedimentary conditions can only be mined by the borehole method. This research aimed to design tools and perform test mining using the borehole method with a spray-suction mechanism. This research produced a novelty, namely, a method and parameters for alluvial tin deposits mining using borehole mining methods, such as the excavation capacity, excavation radius, mining recovery, and dilution factor. The benefit of this research is expected to provide an opportunity to increase the amount of onshore alluvial tin reserves to support tin production.

Semi-Analytical Method for 3D Transient Heat Transfer in Thermally Interacting Fields of Ground Heat Exchangers

The study of heat transfer in ground heat exchangers (GHEs) considering the fluid advection inside the pipes; the heat transfer between the fluid and the ground through the grout material; and the thermal interaction between GHEs is a challenging task. The present paper presents a new semi-analytical method that takes into account the aforementioned effects to consider both the short- to long-term effects of GHEs. The heat transfer between the fluid and grout was studied by a transient multipole expansion considering time-dependent fluid temperatures and an advection model for the pipes obtained from an energy balance on the heat carrier fluid. Thermal interactions were analyzed using an equivalent borehole method while penalizing the transient multipole expansion to include thermal interaction effects. Validation of the short-term predictions was performed by comparing the proposed model to experimental data found in the literature and to an FEA model. The proposed model was then compared with a FEA model in long-term simulations of a geothermal field comprised of 24 GHEs for multi-annual simulation. The method resulted in substantial reduction in computational time while preserving good accuracy when compared with the FEA model.

Prototype Portable Electrical Resistance Tomography

Tomography is a way to describe something non-destructively. Some types of Tomography are Electrical Resistance Tomography (ERT), Electrical Impedance Tomography (EIT), and Electrical Capacitance Tomography (ECT). This study aims to combine the ECT and ERT systems. The combination uses the ERT technique (Borehole method) and develops until it can be used like ECT. This research conducts three significant stages (design making, designed realization, and examination). The examination is carried out by simulation and experimental measurement. The simulation result is compared to the result of the experimental measurement. The result shows that both have the same patterns, but it has the amplitude of voltage difference pattern. It is because the resistivity result affects the measured voltage difference result. The higher the resistivity result of the medium, the smaller the measured voltage difference.Tomography is a way to describe something non-destructively. Some types of Tomography are Electrical Resistance Tomography (ERT), Electrical Impedance Tomography (EIT), and Electrical Capacitance Tomography (ECT). This study aims to combine the ECT and ERT systems. The combination uses the ERT technique (Borehole method) and develops until it can be used like ECT. This research conducts three significant stages (design making, designed realization, and examination). The examination is carried out by simulation and experimental measurement. The simulation result is compared to the result of the experimental measurement. The result shows that both have the same patterns, but it has the amplitude of voltage difference pattern. It is because the resistivity result affects the measured voltage difference result. The higher the resistivity result of the medium, the smaller the measured voltage difference.

Status and future pathways of resin tapping in Nepal: Appeal for special attention

Resin tapping was pioneered five decades ago since the Laxmi Tapping industry started tapping in western Nepal in 1973. Resin tapping is acknowledged as a cost-effective, viable, and adjuvant source of income for rural people with the potentiality for payment for ecosystem services (PES) outside the resin tapping period. This paper explores the SWOT analysis of resin tapping and future pathways to improve this enterprise in Nepal. The systematic and comprehensive literature search was conducted in Google Scholar, ScienceDirect, PubMed, and Scopus; and PRISMA flowchart summarizes the search strategy of the literature survey. SWOT analysis concludes that resin tapping has more strengths and opportunities, but this enterprise is currently under threat due to the shutting down of many resin enterprises with royalty hikes and no incentive. Poor tapping techniques lead to the depletion of pine resources in the long term, so the weakness of the rill method should be counteracted by the modern, cost-effective, more efficient borehole method practiced in many developed countries for resin production. Implementation of the proper policy framework, provision of incentives for enterprise, and sufficient research to create a knowledge base about resin tapping is an urgent need to minimize threats and pedal this enterprise in the right direction. We insist policymakers and stakeholders adopt the integrated forest-based enterprise approach for enabling environment in resin tapping and recommend nine promising value chain upgrading strategies as pragmatic endorsements to execute this enterprise in the long run.

Assessment of in situ properties of municipal solid waste with a large-diameter borehole method.

A Municipal Solid Waste Borehole Assessment (MBA) was developed to assess in situ geotechnical properties of municipal solid waste (MSW) during the boring of gas extraction well construction. A Large-Diameter Borehole Caliper (LDBC) was lowered into the borehole to measure the diameter and record the condition of the wall by time-lapse video photography. The results indicated that the borehole experienced significant radial compression with depth following completion. Radial compressions amounted to approximately 7.5% at 9.14 m, 10% at 21.3 m and 11% at 27.4 m below ground surface. The bulk modulus was estimated by using the captured volumetric strains and reported lateral earth coefficients, and the results showed that it increases with increasing depth. For MSW, the bulk modulus increased up to 13.4 MPa in a linear trend with depth. The unit weights of MSW were obtained using three diameter readings from LDBC, auger barrel outside diameter and outer cutting bit outside diameter. The results showed that the diameter based on outer cutting bit yielded realistic unit weights (5.08-9.68 kN m-3) due to unrealistic calculated saturations by other two assumed diameters. The borehole assessment with LDBC was shown to be an efficient and valuable means for characterising MSW and effectively designing gas extraction wells. The research provided a means to assess the waste mass with accuracy at great depths by directly observing and measuring borehole condition.

2D electrical resistivity imaging to determine depth of andesite spreading at Tanjung Batu, Jambi as eco-friendly exploration of minerals method

Tanjung Batu has potential subsurface minerals in the form of Andesite rocks. Andesite can be used appropriately for infrastructure with excellent physical features, including hardness, compressive strength, density, as well as the water and weather resistance level. Andesite is one type of igneous rock that is widely used in the construction sector, especially infrastructure such as roads, bridges, housing, airports, and seaports. In mining, the depth of mineral exploration usually using borehole method. In this study used electrical resistivity method with dipole-dipole configurations. Electrical resistivity is also capable for identifying Andesite rocks in subsurface without drilling the area because each rock has a different rock resistivity value. In this study used 240 meters of track and 20 meters space of electrodes. Based on 2D Imaging, range of Andesite resistivity in this area was 170 - >1095 Ωm. Andesite depth was at 3.42, 10.6, 18.5 and - 27.2 m.

Methods for intensification of borehole uranium mining at the fields with low filtration characteristics of ores

Purpose. Improving the efficiency of borehole uranium mining and the selection of special decolmating solutions to improve the filtration characteristics of the seam due to effective destruction, as well as by preventing the sedimentation in the productive horizon, depending on the mineralogical composition and structure of sediment-forming materials. Methods. The advantages and disadvantages of the main methods used for improving the filtration characteristics of the productive horizon, when mining the uranium deposits by the borehole method, have been studied. Samples of sedimentation from the productive horizon are taken at the uranium deposit of the Shu-Syrasu depression. The quantitative and qualitative parameters, as well as the peculiarities of the mineral compositions have been determined by the X-ray phase method. A methodology has been developed and laboratory experiments have been conducted on the treatment of sedimentation samples by the drop method using various compositions of selected decolmating solutions. The microscopic method is used to determine the structure and peculiarities of sedimentation before and after treatment with various decolmating solutions. Findings. The effectiveness of the main methods used to improve the filtration characteristics of seams in the uranium deposits, mined by the borehole method, has been determined. The structure and composition of sedimentation, which causes a decrease in the filtration characteristics of the productive horizon, have been determined. To destroy and prevent the sedimentation in the productive horizon, an effective composition of a special decolmating solution using ammonium hydrogen fluoride with the addition of sulphuric acid and surfactants has been selected. An effective method for increasing the filtration characteristics of the productive horizon with the use of special decolmating solutions has been developed and scientifically substantiated. Originality. The use of special decolmating solutions based on ammonium hydrogen fluoride with the addition of sulphuric acid and surfactants according to the developed methodology allows to effectively destroy and prevent sedimentation in the productive horizon of borehole uranium ore mining. Practical implications. The use of the developed decolmating solution and a special methodology for the intensification of borehole uranium mining can reduce the operating costs of its production. This increases the ecological and industrial safety of the work to intensify the leaching of uranium ores.