沙漠地区风积沙加筋土性能

Ordos Plateau Sand Land and Alasan Plateau Sand Land is important economy and building zone of western development and retention continuance development in China. In Hobq sand land and Mu Us sand land of Ordos plateau and Tengger sand land and Ulan Buh sand land of Alxa plateau, informations of the aeolian sand is investigated in field, specimens of undisturbed soil and disturbed soil is took, the field test is took, mineral chemical composition is analyzed, physical property and mechanics property of soil sample is tested and studied. Hobq sand land and Tengger sand land is uniform on granularity and chemistry ingredient's identity, because of genesis and environment condition of aeolian sand. According to direct shear friction tests and pull-out friction tests, it is researched that φ and c of geogrid reinforced aeolian sand, and the reason of that mechanics and engineering properties is reinforced on compound material of geogrid and aeolian sand, and geogrid's role. Pass through soil tests analysis and model tests on aeolian sand of typical sand land, uplift bearing capacity of aeolian sand of spread foundation is tested to 15 kinds geogrid reinforced conditions. According to results of tests, calculation model is defined, theory calculation formula is put forward on bearing uplift load capacity of geogrid reinforced sand land of spread foundation. Ultimate uplift bearing capacity of sand land is researched alone to the tests data, and uplift bearing capacity of geogrid reinforce materials is too, the difference of calculation data and tests data is analysis on sand land bearing capacity and geogrid bearing capacity, it is raised on effective reinforce ways of building geogrid, one and two layer geogrid. and the question of future study is anchoring length of geogrid. The design control conditions could be uplift displacement or uplift load to spread foundation of bearing uplift load. According to aforesaid studies, uplift displacement mechanism is researched, and calculation means of uplift displacement control design is advanced. The field prototype tests have been carries out for uplift under-reamed piles in the loess of droughty area. In these tests, the ultimate uplift bearing capacity, failure mechanism of various size uplift piles were studied，Strength failure mechanism of pile and soil is solved by gradually failure to be due to damage softening and reduction pressure softening of the soil. A theoretical model has been proposed to calculate the ultimate uplift bearing capacity in the loess. On the results, there are theory meaning to research of geotechnical engineering, and application perspective of highwayengineering, railway engineering, transmit electricity engineering,etc.

研究沙漠地区土工织物加筋风积沙土的物理力学性质以及通过室内和现场试验研究，在下压和上拔荷载作用下的应力场、位移、强度机理、破坏模式和承载力，提示该土工织物加筋土的基本性质和力学行为，进一步分析其影响因素和改良、加固土体的机制，以及固沙作用。这一研究将对沙漠地区工程建设中有关的工程设计和施工提供理论根据并有广泛的应用前景。