Abstract: the landslide problem is not only a threat to the production safety, some even havoc on local vulnerable ecological environment, and thus the slope stability monitoring is of great significance. The slope stability of acoustic emission monitoring on the spot to get a certain application, but the basis of related research is very weak. Experimental study on the shear failure process of rock acoustic emission activity characteristics and similar material in the process of uniaxial compression AE activity characteristics, using the similar material model to simulate the process of landslide and the acoustic emission monitoring. Experimental results for field monitoring sensor in the layout, the determination of critical parameters, etc.
Key words: landslides; Acoustic emission; The experimental research; Similar material
1 landslide hazard and monitoring
China's northwest, southwest and some of the mountains, there are many natural soil and rock slope hilly region. Due to reasons such as vegetation destruction, slope instability or failure cause landslides, often cause traffic jams, plugging jiang may, such as disasters, or even on the local ecological environmental havoc [1]. In transportation, water conservancy, water and electricity, etc, there are a lot of slope in open-pit mine production safety is a serious hazard.
Study [2], the landslide is a landslide, development happened until (till) the final process, is a long-term, intermittent, the strong with the weak transient, has obvious alternate process of the active and relatively stable. From this perspective, the landslide can be forecast. There are many types of landslide prediction method, such as deformation, stress, temperature and seepage observation, telemetry, and acoustic emission monitoring and so on. In these methods, acoustic emission monitoring method has the advantages of dynamic real-time monitor to locate the break point, and the convenience of information transmission, thus attracting widespread attention [3 ~ 5].
Although acoustic emission technology must be used in slope stability [6], but the whole landslide sliding process simulation studies and rock acoustic emission features of the sound source localization research basic research aspects, such as still need to do a lot of work. In this paper, based on the status quo of this aspect research rarely, experimental study on the shear failure process of rock acoustic emission characteristics and similar material in the process of uniaxial compression AE activity characteristics, the landslide process of similar material simulation and the acoustic emission monitoring, in order to cause the attention of many researchers have been studying this work.
2 rock shear test of AE events
The influence factors of landslide landslide can be classified as internal factors and external factors. Internal factors mainly refers to the lithology of landslide, rock strength, degree of slope rock mass integrity and broken and the surface of the master (weak surface) on the mechanical properties (shear strength), etc. Of yudonghe landslide is given priority to with shear failure, therefore, the study of shear failure process of rock AE activity characteristics, the landslide destruction process of recognition and damage location of qualitative discrimination has important theoretical significance and application value.
2.1 AE activity characteristics of limestone and granite shear test
8-channel acoustic emission instrument, the AET - 5500 standard specimens of limestone and granite (50 mm x 50 mm x 50 mm)
Shear test and record the AE signal, each choose a typical test results are analyzed. 

Figure 1 and figure 2 respectively are limestone and granite shear test results of AE. Can be seen from the diagram, two kinds of rock shear failure process has obvious AE activity, starting earlier, there was a significantly close to limit damage signal, release a large energy. 

2.2 the significance of limestone and granite shear test results of AE
(1) two kinds of rock shear failure process has obvious AE activity, so acoustic emission monitoring of landslide is feasible. In rocks at the same time, there was a significantly close to limit damage signal, release a large energy, and the main failure of landslide prediction is possible.
(2), as the representative of sedimentary and igneous rocks, limestone and granite respective AE activity has obvious difference. In the process of the shear failure, AE activity of granite significantly more than limestone. Other test results also show that different types of rock AE activities with different characteristics. According to this characteristic, can further analysis to establish the AE activity characteristics and the corresponding relationship between the rock types, when for acoustic emission monitoring of the slope, according to the characteristics of the AE signal receiving and signal could be judged to be made by what kind of rock mass, coupled with the slope geological drilling of lithologic distribution in the histogram, can undertake the landslide damage point positioning qualitative judgment.
(3) two kinds of rock near the main rupture occurred in AE activity has increased dramatically, and then decreased significantly, then the main rupture occurred phenomenon. Limestone in stress reaches about 74% of the rock strength when AE activity has increased dramatically, and granite occurred when the stress reaches about 90% of the rock strength. This gives critical forecast increased the difficulty of landslide instability, need to further study the mechanism of this phenomenon and its rule.
3 AE activity characteristics of similar materials under uniaxial compression
Analog simulation is one of the methods usually used to solve engineering problems. For acoustic emission monitoring of landslide, under laboratory conditions similar simulation experiment simulated the whole process of landslide, analyze the whole process of slope unstability characteristics under different conditions, determine the critical period of sensitive parameters and the critical value, the field observation results and confirm all is of great significance. 

Similar material using cement, gypsum, sand ratio is 3:5:2, made of standard specimen Φ 50 * 100 mm. Acoustic emission instrument used for AET - 5, 500. Figure 3 is similar materials of AE testing results of uniaxial compression. AE activity characteristics as follows: when the load stress added to 10% of the ultimate strength in AE activity, until burst, when close to limit damage, AE activity decreased, energy is also small. It's structure is loose, lower material fracture strength of AE activity features.
Similar material in the process of uniaxial compression produced strong AE activity, showed similar material simulation for AE monitoring landslide process is feasible. At the same time, the similar material in the process of uniaxial compression AE activity and natural rock AE characteristics have obvious difference, this reflects the difference of similar material and natural rock on the fabric.
4 similar material simulation AE monitoring in the process of landslide
4.1 the slope model
Made from slope model with similar materials, sand, cement and gypsum ratio of 4, 6, 4, the uniaxial compressive strength of 0.2 MPa. Model size: 800 mm, 200 mm wide, 8, 400 mm, length is 990 mm, the weak surface model within the preset. At the top load jack setting force transducer PA1, setting displacement sensor measurement of 2, one vertical displacement for PA2, horizontal displacement set a PA3. PA1, PA2 and PA3 access acoustic emission instrument analog channel respectively, set up the parameter of the test results and change the relationship between the AE signal. Acoustic emission sensor layout eight, setting position as shown in figure 4, uniform near the slope model of slip line. 

Test is produced by the top jack load gradually until landslide movement, the vertical and horizontal displacement of the load size, the landslide are measured by the sensor, the AE signal measured at the same time. [/ mem]
4.2 acoustic emission test results and analysis
Load to limit value, the vertical displacement, horizontal displacement is larger, about 3.2 mm. Continues to increase when the displacement of landslide has started to slip, load instead dropped to zero, the vertical and horizontal displacement increase sharply. In 2.5 minutes, after the "quiet period" as the load changes a little, that is a sharp move.
As the change of slope sliding speed, accordingly AE events is also rising, as shown in figure 5, and 6. Mutations in the final displacement and AE events before the surge, also recorded the launch of the "quiet period". Produce landslides, first at the top, as a result, 1 #, 2 #, 3 # probe receives the acoustic emission signal is stronger.
As can be seen from the tests:
(1) the slope instability of landslide displacement (horizontal and vertical) in the process of changing trend with the monitoring to the change trend of AE events is consistent, when approaching landslide displacement and AE events are mutated. So can use similar material model to simulate the process of slope instability. 


(2) with the shear test of rock, the instability of similar material model - slip also appeared in the process of "quiet period" before the main rupture. This is the rock of energy accumulation process, not the real "calm".
(3) the AE source location results show that the model of the upper first, in field application, should be combined with the similar simulation analysis of possible positions first yudonghe landslide points, the AE sensor as a reference for setting.
5 conclusion and discussion
(1) the whole process of rock shear test are obvious AE activity, closer to the ultimate strength appeared a significant signal; Different rock AE activity obviously different, can be used as a qualitative judgment of landslide damage point positioning.
(2) of similar material appeared in the process of uniaxial compression strong AE activity, has the obvious difference with natural rock AE activity.
(3) the instability of similar material simulation process is completely feasible, studies have shown that the experimental study for sensor layout, provides the basis for the determination of the critical parameters such as or reference.
(4) need to be further in-depth study of the contents are: the study of landslide of AE in the most sensitive feature, the determination of critical prediction parameters, etc.
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