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| IN-SITU TESTING STUDY OF ACCUMULATIVE FORMATION LANDSLIDE REINFORCED BY MICROPILE GROUP |
| ZHU Benzhen1，SUN Shuwei1，2，ZHENG Jing1 |
(1. Northwest Research Institute Co.，Ltd.，China Railway Engineering Corporation，Lanzhou，Gansu 730000，China；
2. Department of Hydraulic and Hydropower Engineering，Tsinghua University，Beijing 100084，China) |
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Abstract In-situ test on micropile group for reinforcing accumulative formation landslide was carried out. The monitoring data indicates the deformation mode of landslide was very complicated，which went through several stages as shallow sliding，deep sliding and temporary stable. The deformation of subgrade is controlled by micropile group well ensuring the safety of traffic. There is a great difference in the load sharing ratio among different rows of micropile. During the displacement of the landslide mass reaches its maximum value，the front row of micropile resist the maximum value of load，followed by the rear row of micropile，while the middle row of micropile resist the smallest value of load. As the landslide tends to be stable，the load sharing ratios among different rows of micropile tend to be uniform. Besides，comparing the testing results with the theoretical results，it was shown that elastoplastic load-displacement curve method can well reflect the lateral force characteristics of micropile group under landslide thrust. Fixed micropile head will induce the stress concentration at the top and cause the larger bending moment of micropile within the range of 2 m beneath ground. Therefore，the hinged bearing between micropile and the rigid capping beam may be adopted.
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Received: 31 December 2009
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2011, Vol. 30 
