Shandong University

The Chinese University of Hong Kong

Huaifeng Sun

Shucai Li

Bin Liu

Yang Yang

Lichao Nie

Zhengyu Liu

Jie Song

Xinji Xu

Chuanwu Wang

Lei Xu

Yao Li

Tingyu Hao

Nuoya Zhang

Xiangxue Ma

Jing Wang

Qingmei Sui

Chunjin Lin

Heng Zhang

Faye Zhang

Rui Liu

Jing Yang

Jishan He

Diquan Li

Jingbo Weng

Yuqiang Cao

Hao Zhou

Ziqiang Zheng

Shangbin Liu

Wenhan Li

Yuzhen Zhu

A method and system for generating a logarithmic non-uniform pseudo-random electromagnetic exploration signal including: constructing two or more basic unit signals, according to an exploration requirement, that are stairstep signals obtained by superposing in-phase periodic square wave signals, a frequency ratio between adjacent periodic square wave signals is 2, and the two or more basic unit signals meet the following requirement: if a lowest dominant frequency in a first basic unit signal is a fundamental frequency, lowest frequencies of the remaining basic unit signal are l×2times the fundamental frequency, where l is an odd number except 1, and m is a natural number; and superposing the two or more basic unit signals to obtain a logarithmic non-uniform 2sequence pseudo-random signal. A logarithmic non-uniform 2sequence stairstep signal is constructed within a limited frequency interval, and requirements of prospectors for a higher frequency density within a specific frequency interval are met.

Method and system for generating logarithmic non-uniform pseudo-random electromagnetic exploration signal

A method and system for exploring hidden karst pipelines, mainly comprising: determining an upstream and a downstream of an underground karst pipeline; laying a grounding electrode at the upstream and the downstream respectively; establishing an electromagnetic emission system through underground karst water channels in the underground karst pipeline in a survey area, a transmitter and a generator; arranging a receiving system through an air mobile equipment towing a receiver as a receiving end; turning on the electromagnetic emission system; a generator supplying power to emission circuit; controlling the air mobile equipment to move along routes to collect signal continuously above the survey area, to complete an area-based measurement, and obtain observed data in the whole survey area; processing the observed data; delineating a concrete distribution of the underground karst water channels from the to the, such as a net-shaped path diagram or a tree-shaped path diagram.

Method and system for exploring hidden karst pipelines

A novel tracing apparatus includes an electromagnetic transmitting system, a multi-frequency transmitting antenna, electrodes, and a receiver. The electromagnetic transmitting system is at an upstream point and includes a generator and a transmitter having a capacitor; the transmitting antenna penetrates into a detected aquifer through karst collapse or a drill hole; the electrodes and the receiver are at a downstream point, and include two pairs of electrodes orthogonally distributed and located in a cofferdam formed by downstream water; and the receivers collect electric signals in the electrodes. The apparatus is based on good electrical conductivity of water, and can use electromagnetic signals as a tracer for rapid observation. Compared with traditional tracers, electromagnetic signals propagate fast in water, are stable in property, and free of pollution. This apparatus can be applied to groundwater tracing detection, and problems with the traditional tracers having poor timeliness and being environmentally unfriendly are resolved.

Tracing method and apparatus based on electromagnetic field

A system and method for controlled-source electromagnetic exploration is based on staggered frequency excitation of crossed sources. Different high-order pseudo-random signals are transmitted using two sources, respectively, each set of high-order pseudo-random signals may contain sufficient frequencies within a same complete frequency range, exploration frequencies of the two sets of signals are completely staggered, simultaneous transmission by the two field sources is implemented, and different polarization modes do not affect each other and are separated from each other. Moreover, different measuring line directions at a receiving terminal can be observed simultaneously, and each measuring point has two polarization directions, thus greatly improving the exploration efficiency and the data volume.

System and method for controlled-source electromagnetic exploration based on staggered frequency excitation of crossed sources

The present invention presents a tunnel construction large-scale integrated geophysical advanced detection model test device. The model test device includes a tunnel surrounding rock, a main tunnel model, a model test case, a water-containing geological structure device, a numerical control automated construction device and a main control chamber. The model test device is a large-scale integrated geophysical advanced detection model test device meeting the detection using a seismic wave method, an electromagnetic method and a direct-current electric method. By using the geophysical advanced detection model test device, the geophysical response features of the water-containing geological structure device in front of a tunnel face may be studied, multiple geophysical advanced detection forward and inversion methods for the water-containing geological structure device are verified, and the relationship between some geophysical detection method results and water burst quantity is studied, for the advanced prediction and water burst quantity prediction in actual engineering.

Tunnel construction large-scale integrated geophysical advanced detection model test device

The present invention presents a comprehensive advanced geological detection system carried on a tunnel boring machine. The comprehensive advanced geological detection system includes a multifunctional combination main frame, an induced polarization detection device, a seismic wave detection device, an integrated junction device, a borehole ground penetrating radar detection device and a comprehensive interpretation and decision system; the multifunctional combination main frame includes a time division multiplexing control module, an excitation source control module and a parallel data acquisition module; the excitation source control module outputs trigger signals to the three detection devices respectively, and the three detection devices respectively output measurement data and feedback signals to the time division multiplexing control module through the parallel data acquisition module; and the comprehensive interpretation and decision system supports geological interpretations and decisions through the inversion/migration imaging joint inversion of three detection methods.

Comprehensive advanced geological detection system carried on tunnel boring machine

The invention discloses three-dimensional focusing induced polarization equipment for advance geological prediction of a water inrush disaster source in underground engineering, comprising a constant-current multiplex transmitter, an intelligent multichannel receiver, an automatic multi-electrode switch, an industrial personal computer, an observation electrode array and shielding electrodes, wherein electrodes in the observation electrode array are respectively used as a source electrode and observation electrodes; the industrial personal computer controls the constant-current multiplex transmitter to transmit currents of the same polarity to the shielding electrodes and the source electrode, so that the currents of the source electrodes are nearly directed straight ahead of a driving face under the action of the shielding electrodes; the observation electrodes are used for scanning data acquisition, and the data are fed back to the industrial personal computer through the intelligent multi-channel receiver; and the industrial personal computer controls the automatic multi-electrode switch to change the source electrode.

Three-dimensional focusing induced polarization equipment for advanced geological prediction of water inrush disaster source in underground engineering

Disclosed is an advanced detector system and method using a forward three-dimensional induced polarization method for a TBM (Tunnel Boring Machine) construction tunnel. A narrow detection space of a full-face excavated tunnel is fully used, a controller controls doors of a source and measuring electrode compartment and a shielding electrode compartment to open and controls a corresponding hydraulic delivery device to automatically and quickly arrange a source electrode system, a measuring electrode system and a shielding electrode system. Under the action of a shielding current system, tomography detection supply current is directed ahead of the working face. Three-dimensional geologic information can be obtained, and the relationship between an induced polarization half-decay time difference and a water quantity can be used to quantitatively forecast the water quantity of a water-bearing body, and meanwhile, the half-decay time difference parameter has a high capacity of distinguishing free water from bound water.

Advanced detector system and method using forward three-dimensional induced polarization method for TBM construction tunnel

Growing community of inventors

Jinan, China

Huaifeng Sun