МЕТОД ОЦЕНКИ ПРОСАДКИ ФУНДАМЕНТОВ ТОННЕЛЕЙ В ЛЕССОВЫХ ГРУНТАХ Evaluation method for self-weight collapse deformation of tunnel foundations in thick loess

Shengjun Shao, Zhi Wang, Shuai Shao

Аннотация


Просадка фундамента тоннеля в лессовых грунтах при размокании вышележащего слоя лесса может привести к повреждению конструкции облицовки. Представлен метод определения сжимающего напряжения при просадке, в котором учитывается собственный вес конструкции, давление окружающей породы и деформация при разрушении под давлением вскрыши. Разработан метод расчета коэффициента просадочности, который учитывает структурный индекс, структурный предел текучести при сжатии и физические параметры лесса. Моделируется и анализируется пластическая зона облицовки при разрушении, и предлагается деформационный стандарт классификации степени разрушения основания туннеля.

Полный текст статьи публикуется в английской версии журнала
«Soil Mechanics and Foundation Engineering” vol.59, No.1

Collapse deformation of loess tunnel foundation may appear when the overlying loess stratum is soaked, the resulting additional effect could cause damage to the lining structure. In this paper, a method for determining the collapsible compressive stress of a loess tunnel foundation is presented, that considers the dead-weight of lining structure, surrounding rock pressure and collapsibility deformation under overburden pressure. In addition, a calculation method of self-weight collapse coefficient under collapsible compressive stress is established, which considers the structural index, structural compressive yield stress and physical parameters of loess. Furthermore, the plastic zone of the lining under the action of differential settlement during collapse deformation are simulated and analyzed, and the classification standard for the grade of collapse deformation of the tunnel foundation is proposed with reference to the control standard of a railway subgrade.

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