High-density Electrical Method Research Articles

Comparative Study on the Application of High-Density Electrical Method and Ground Penetration Radar in Fault Surveying

In this study, the basic principle of high-density electrical method and the basic theory of ground penetration radar (GPR) are described. The fault surveying at Wudang is taken as an example to summarize the image features of apparent resistivity section of fault and those surveyed by GPR. The applications in fault surveying of the two methods are compared.

Study on Well Location Methods in Deep Buried Area of Karst Aquifer-Giving an Example in Boai County, Henan

Based on the groundwater exploration project in serious water shortage region (Jiaozuo, Henan) of Huaihe valley, the paper explores a comprehensive borehole location method from water detection experience in northern carbonate rock hilly area of Boai county, Henan. The results show that in the deep buried area of Karst aquifer, the combination of hydrogeologic survey-structural controlled water theory, high density electrical method and V8-controlled source audio magnetotelluric is effectively in borehole location ,which can greatly reduce the rate of "dry well" and improve the proportion of completion.

Study on the Effects of Tide-Induced Interface of the Fresh-Saline Groundwater Based on High Density Resistivity

Under the background of global environmental change and the influence of human activities on the environment increasingly significant, the research of continental-oceanic interaction has become the current hot issues in geological field research. The continuous dynamic monitoring of groundwater will be conducted, and technology validation about the dynamic changes of groundwater vary with tidal interactions will be studied in the seawater intrusion area of the laizhou bay using high density electrical method in this research.The results suggest that，If we obtain the value of electrical characteristics of the fresh-saline groundwater by numerically or laboratory experiments, Such as we choose 15 Ω· m in Laizhou Bay, we can use high-density electrical to continuous monitor to solve the Scientific Problems of the interface of the fresh-saline groundwater with the effect of tidal variation.

Experimental Studies on Subgrade Failure Detection of High Density Electrical Method for Opening Road

By experiment,adopt clay as the transfer medium between copper bar and pavement,change the grounding mode of electrode,high density electrical method was used for subgrade failure detection. The experiment result show that this method can control all most ground resistance within 10KΩm and the subgrade failure can be detected. Because of the electrode grounding area is larger and the resistivity is higher,caused the inversion result has some error. This conclusion of experiment can provide reference for subgrade failure detection of high density electrical method for opening road.

Tunnel Karst Disease Risk Estimation by Advance Geological Forecast

The concept of "tunnel karst disease risk estimation" is put forward for the first time, which is applied in advance geological forecast of Shajinjie tunnel. This method can help us recognizing the main hole advanced prediction work to improve the forecast work pertinence. In the forecast method, it takes the head in integrating the surface high-density electrical method with the georadar method, which improves the forecast accuracy of serious karst disease. The actual excavation results show that the advance geological forecast results meet the actual situation highly.

Stability Analysis of Side Slope under Normal and Rainfall Conditions

The paper studied a side slope engineering of highway in K29+450~K29+900 sections by making an on-site survey of landform and geological features of the side slope. By combining drilling, high-density electrical method and numerical simulation method, the depth and range of the sliding surface were determined. The stability of the side slope after an excavation in a normal and a rainfall conditions was analyzed using numerical simulation method, and simulation results show that in the normal condition the safety factor of the side slope is 1.12, and it is 1.05 in the rainfall condition; the distribution of plastic zones is wide, especially in the rainfall condition, the side slope has a large deformation and is in an unstable state. When a program of side slope reinforcement is chosen, the impact under rainfall condition should be considered in order to ensure long-term stability of side slope.

Liquefaction Survey and Case Analysis in Wenchuan Earthquake

Total 163 survey points distributed in 104 liquefied and non-liquefied sites were selected in the Wenchuan earthquake liquefaction database, where 50 survey points were from intensity VI region. Borehole data show that pure sandy layers could hardly be identified in Wenchuan earthquake affected areas, instead gravel soil layers mingled with sand silty or pebble prevalently exist. Songbai village which suffered severe liquefaction was chosen for case study in this paper. Through MASW and high density electrical method testing, three soil layers can be distinguished from the testing cross section. The discontinuity of resistivity of the first layer by the high density electrical method indicates the location of sand ejection. The grain size distribution curves of sand ejecta were different from drilling soil samples, which explanation need further investigation.

Application of Comprehensive Geological Exploration for Engineering Site Option

In the process of engineering prospective design and constructing, it is necessary to avoid the adverse impact of geological phenomena, such as fault, karst and landslide. Therefore, it’s important to choose a favorable project address by scientific and effective detection with engineering geological conditions. The main exploration method for geological conditions is the geophysical exploration, including: high density electrical method, ground penetrating Radar, seismic exploration method and so on. The discrimination result with a single geological method changes much, and it is difficult to make an accurate analysis of the geological conditions. So we should composite a variety of exploration methods. In this paper, it expounds the fundamental, the working method, data explanations of the high density electrical method and ground penetrating Radar firstly. And then it takes exploration of candidate sites of an aluminum waste disposal plant for example, the geological conditions of candidate sites are analyzed under the two geophysical methods. The study results of engineering site option have a positive role in guiding the work.

The Corresponding Numerical Analysis of Dike Typical Diseases and Electrolog Data

Dike is an important component of Yellow River flood control system, but its security situation is not optimistic. High-density electrical method is an effective mean of dike typical diseases detection, we use steady-state current transfer analysis of software ANSYS to establish the numerical simulation model to analyze the detection resolution effects of dike typical diseases depth and scale changes on different detection devices of high-density electrical method, establish the correspondence of dike typical disease and electrolog data.

The Corresponding Theory Study of Dike Typical Diseases and Electrolog Data

Dike is an important component of Yellow River flood control system, but its security situation is not optimistic. High-density electrical method is an effective mean of dike typical diseases detection, we establish theoretical model to analyze the detection resolution effects of depth and scale changes of dike typical diseases on different detection devices of high-density electrical method, establish the correspondence of dike typical diseases and electrolog data.

Survey and Analysis of the Regularity of the Surface Crack in the Loess Tunnel of the Special Passenger Line

We have done a survey about the surface crack of the loess tunnel of Zheng-xi passenger railway by field survey, geophysical exploration test and pit detection and also have researched the produced regularity of the surface crack of the loess tunnel, especially about in the depth. The result of the survey and the detection indicates that: (1)The surface crack is mostly visible in the shallow area of the loess tunnel entrance. The visible width of the surface is extensive (0.2~200mm) and it is mostly visible in the tunnel, the depth of which is below 60m. The visible or wide cracks mostly appear in the area whose surface settlement is above 80mm. The width of the surface crack of the tunnel, which has a more shallow depth and a larger settlement, is much wider. (2)The effect of the High-density electrical method reflecting the development of the surface crack is obvious. The method of seismic reflection wave and seismic imaging is more accurate than Rayleigh wave in interpreting depth development of the crack. (3)There are two kinds of performance of the surface crack: longitudinal crack that inclines to the inside on both side of the tunnel and circumferential crack perpendicular to the axis of the tunnel. (4)The visible crack depth of the surface crack is limited, which is about 3.0~10m and it always doesn't reach the top of the tunnel. The depth by the geophysical exploration test is much more depth, which is about 10~15m.

The Study on Chemical Weapons Abandoned by Japanese in China: Aim to Ascertain the Burial Sites and Pollution Disposal

Lots of chemical weapons abandoned by Japanese in China during World War II lead to serious harm to human health as well as inducing abrupt casualty accidents. It is put forward that some geophysical methods such as low-altitude thermal infrared remote sensing, 3D high density electrical method and 3D geological radar combined with small-diameter exploratory hole method can be used for detailed detection, to ascertain the burial sites, spatial distribution and pollution degree of approximate confirmed weapons in this paper. Then, on the basis of this, take safety assessment and make programs to manage and prevent collision pertinently in order to establish technique method system of pollution investigation and disposal which is suitable for various conditions and different pollution degree.