Tài liệu miễn phí Địa Lý

Download Tài liệu học tập miễn phí Địa Lý

Nghiên cứu quy luật phân bố ứng suất trước gương lò chợ cơ giới hóa hạ trần than nóc với chiều cao khấu lớn

Bài viết dựa trên điều kiện địa chất lò chợ 4108 mỏ Ping Shou, ShanXi (Trung Quốc), sử dụng mô hình số hóa FLAC3D, mô phỏng quá trình khai thác lò chợ khi chiều cao lớp khấu là 4,2 m, sau đó tiến hành phân tích quy luật phân bố trạng thái ứng suất phía trước gương lò chợ khi chiều cao lớp khấu lớn.

4/7/2023 4:32:29 PM +00:00

Ứng dụng phương pháp mô hình số xác định ảnh hưởng của khai thác hầm lò đến các công trình thuộc cụm kho G9 mỏ than Mông Dương bằng phần mềm UDEC - 2D

Công tác khấu than ở lò chợ tạo nên các khoảng trống, làm mất thế cân bằng tự nhiên của ứng suất trong lòng đất, gây nên các hiện tượng dịch chuyển biến dạng đất đá và phá hủy công trình, môi trường. Trong phạm vi bài viết, các tác giả sử dụng phương pháp mô hình số để đánh giá ảnh hưởng của khai thác ở lò chợ vỉa L7 cánh Đông đến các công trình trên mặt thuộc cụm kho G9 mỏ than Mông Dương.

4/7/2023 4:32:20 PM +00:00

Giải pháp cải thiện điều kiện vi khí hậu cho lò chợ mỏ than Mông Dương

Bài viết phân tích hiện trạng vi khí hậu, sự phân bố nhiệt độ khu vực lò chợ, nguyên nhân làm gia tăng nhiệt độ lò chợ và các giải pháp làm mát trong mỏ hầm lò. Từ đó đề xuất giải pháp sử dụng điều hòa không khí để giảm nhiệt độ, cải thiện điều kiện vi khí hậu cho lò chợ CGH L7 mỏ than Mông Dương.

4/7/2023 4:32:13 PM +00:00

Study on the effect of vibration parameters on the screening efficiency of the circular vibrating screen using discrete element method

A circular vibrating screen is a device for the separation of bulk materials into granules of different sizes, which is widely used in screening plants. The screening efficiency depends on various parameters, such as the vibration amplitude, vibration frequency, slope of screening surface, material properties, throwing index, etc.

4/7/2023 4:32:06 PM +00:00

The effects of salt contents on the geotechnical properties of some soft soils in the coastal area of Vietnam

In this study, the effects of salt solutions with different seawater proportions on some geotechnical properties of soft soil distributed in some areas from Mong Cai to Thanh Hoa province have been extensively investigated. The undisturbed soil samples were soaked into different salt solutions for ten days before testing.

4/7/2023 4:32:00 PM +00:00

Study on quality characteristics of raw and fine sericite ores in Son Binh area, Ha Tinh province

In this paper, a range of analysis methods (XRD, XRF, SEM-EDS, ICP-MS, and AAS) were used to characterize the quality of Son Binh raw and fine sericite ores. The analytical results indicate that the Son Binh raw sericite ore belongs to a mineral group of sericite - quartz. Non-metallic mineral compositions are mainly quartz, sericite, and pyrophyllite.

4/7/2023 4:31:52 PM +00:00

3D slopes stability modeling for landslide early warning design at Halong city area

This study presents the results of time-variant slope stability analysis by combining the limit equilibrium method with geospatial data. The slope stability analysis was conducted at six times, with the variation of pore water pressure ratio, ru corresponding to the change of rainfall in the study area

4/7/2023 4:31:46 PM +00:00

X-ray fluorescence major element analyses of silicate rocks by creating a calibration curve with the S2 Ranger instrument

Japanese silicate rock standard samples and the S2 Ranger XRF Spectrometer are utilized to create a calibration curve for analyzing major element concentrations of silicate rocks. The calibration curve created by the S2 Ranger XRF Spectrometer is proved to be suitable for analyzing major element concentrations of silicate rocks.

4/7/2023 4:31:39 PM +00:00

Rainfall-Runoff and Inundation of Ma River Basin Under Global Warming

Vietnam has been considered as one of the most vulnerable countries in the world under global warming. The Intergovernmental Panel on Climate Change (IPCC) estimated the increasing trend in the total annual rainfall in Vietnam in the mid-21st century, where 70% of the amount of rainfall will be delivered by the summer monsoon.

4/7/2023 4:31:29 PM +00:00

Study on the capability of treating Fe, Mn in the wastewater of several aquatic plant species

Phytoremediation is a method of using plants to extract, isolate or detoxify pollutants through chemical, physical and biological processes. For years, this method has been considered as an effective method for wastewater treatment thanks to its high efficiency, low cost, stability, and simplicity of operation. Besides, this wastewater treatment technology is environmentally friendly since it increases biodiversity and contributesto the landscape of the environment and local ecosystems.

4/7/2023 4:31:22 PM +00:00

The initial research on the compressive strength of mortar when using bottom ash from thermal power plants to replace natural sand in construction

The paper presents the compressive strength of mortar samples when replacing naturalsand by bottomash of An Khanh and CaoNgan thermal power plants (TPPs) in Thai Nguyen province. Experimental research is the main method applied in this research.

4/7/2023 4:31:04 PM +00:00

Using numerical modeling method for design and constructive controlling of excavation wall in Madison Building, Ho Chi Minh city

The basement of a high-rise building is the optimal space for technical systems and parking. However, the construction in narrow urban areas usually has many unstable hazards. In this study, a numerical model has been established and calibrated using the finite element method on Plaxis 2D software that allowed well control of the design and construction processes of the Madison Building basement.

4/7/2023 4:30:54 PM +00:00

Applying the Equivalent Plane Strain solution to design the soft soil improvement by vertical drains

The paper presents the application of this solution to design soft soil improvement by sand drains at Km 3+130 Vi Thanh - Can Tho. It indicated that the settlement results of the soft ground treatment design based on Equivalent Plane Strain solution are similar to

4/7/2023 4:30:46 PM +00:00

Study on establishing a mining group of deposit and an exploration grid pattern for lead - zinc ore in Ban Lim area, Cao Bang province

The paper-based on collecting, synthesizing, and geological processing data. In addition, mathematical methods were also applied to recognize studied objects of the exploration process using a quantitative description.

4/7/2023 4:30:39 PM +00:00

A 2-D numerical model of the mechanical behavior of the textile-reinforced concrete composite material: effect of textile reinforcement ratio

This paper presents a numerical approach at the mesoscale for the mechanical behavior of TRC composite under tensile loading. A 2-D finite element model was constructed in ANSYS MECHANICAL software by using the codes. The experimental results on basalt TRC composite from the literature were used as input data in the numerical model.

4/7/2023 4:30:32 PM +00:00

Experimental study on use fly ash in underground construction concrete

Fly ash utilization in concrete as partial replacement of cement is gaining importance day by day. In Vietnam, fly ash has been used to as roller compacted concrete of Son La hydroelectricity, rural road concrete and unburnt bricks. This paper studies the use of fly ash in concrete, cement is replaced partially by fly ash in underground construction concrete.

4/7/2023 4:30:21 PM +00:00

Impact of asymmetrical phenomena on asynchronous three-phase motors in operation mode

The paper investigates the effect of asymmetry voltage on the normal operation mode of a three-phase asynchronous motor based on the electromagnetic transforming method of electric machines and simulating on Matlab-Simulink.

4/7/2023 4:30:14 PM +00:00

Research on technical solution of displacement and deformation monitoring of high-rise buildings in real time

This article presents a technical solution of displacement and deformation monitoring in real-time based on GNSS CORS technology. The components and principles of operation of the monitoring system for displacement and deformation have been designed and established.

4/7/2023 4:30:03 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 10: Culvert and ditch design

Lecture Hydraulics and hydrology training - Chapter 10: Culvert and ditch design, after studying this section will help you understand: the different types of culverts; know the culvert design process for conveyance; complete a roadway culvert design using nomographs and determine headwater to diameter ratio (HW/d).

4/6/2023 10:55:48 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 8: Hydraulic issues for design-duild vs. design-bid-build projects

Lecture Hydraulics and hydrology training - Chapter 8: Hydraulic issues for design-duild vs. design-bid-build projects, after studying this section will help you understand: Approved Hydraulic Reports; Build per plans; Change orders; WSDOT is responsible for the designs and bears the risks.

4/6/2023 10:55:40 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 7: Introduction to the hydraulic report

Lecture Hydraulics and hydrology training - Chapter 7: Introduction to the hydraulic report, after studying this section will help you understand: The hydraulic report is intended to serve as a complete documented record containing the engineering justification for all drainage modifications that occur as a result of the project. The primary use of a hydraulic report is to facilitate review of the design and to assist in the preparation of the PS&E.

4/6/2023 10:55:33 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 6: How to use the HM and HRM

Lecture Hydraulics and hydrology training - Chapter 6: How to use the HM and HRM, after studying this section will help you understand: Conveyance policy and design, hydrology and hydraulic methods, bridge design, stream design, LWM, fish passage, pipe materials.

4/6/2023 10:55:26 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 5: Fish passage, stream design, bridge scour

Lecture Hydraulics and hydrology training - Chapter 5: Fish passage, stream design, bridge scour, after studying this section will help you understand: Anything that hinders any life stage of fish from moving through a water way.

4/6/2023 10:55:16 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 4: Hydrologic processes and large woody material

Lecture Hydraulics and hydrology training - Chapter 4: Hydrologic processes and large woody material, after studying this section will help you understand: fluvial geomorphic processes, hydrologic processes, large woody material (lwm), streambank stabilization.

4/6/2023 10:55:03 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 3: Pavement drainage - pipe network sizing

Lecture Hydraulics and hydrology training - Chapter 3: Pavement drainage - pipe network sizing, after studying this section will help you understand: develop basin hydrology flowing to the structure(s) you are designing; know the different types of grate inlets, catch basins, and manholes; complete inlet spacing calculations using the wsdot spreadsheet.

4/6/2023 10:54:56 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 2: Hydraulics and hydrology methods

Lecture Hydraulics and hydrology training - Chapter 2: Hydraulics and hydrology methods, after studying this section will help you understand: santa barbara urban hydrograph method (sbuh); continuous simulation method (western wa for stormwater design); united states geological survey (usgs) regression equations (streamstats); usgs streamflow gages published flow records.

4/6/2023 10:54:45 PM +00:00

Lecture Hydraulics and hydrology training - Chapter 1: Hydraulics manual policies

Lecture Hydraulics and hydrology training - Chapter 1: Hydraulics manual policies, after studying this section will help you understand: Design drainage facility to convey water across, along, or away from the highway in the most economical, efficient, and safe manner without damaging the highway or adjacent property.

4/6/2023 10:54:34 PM +00:00

River restoration and rehabilitation

River restoration and rehabilitation. After studying this section will help you understand river dynamics and response; three laws for river restoration; ten guidelines for river restoration...

4/6/2023 10:52:39 PM +00:00

Lecture River engineering and modeling

Lecture River engineering and modeling. After studying this section will help you understand degradation, scour and gravel mining; aggradation, sedimentation and flushin; adredging and sediment management...

4/6/2023 10:52:28 PM +00:00

Lecture River meandering and braiding

Lecture River meandering and braiding. After studying this section will help you understand brief overview of river and meandering characteristics, and riprap design: river meandering and braiding, riprap design, case study gupo bridge, south Korea.

4/6/2023 10:52:21 PM +00:00