地下渗漏条件下地基与隧洞响应的离心模型试验研究

Centrifugal model tests on behavior of soil and tunnel under underground water leakage

地下管线的渗漏会导致路面发生沉降,威胁着周围土体和相邻结构的安全。采用离心模型试验方法探究了地下渗漏条件下周围土体与结构的响应。通过测定土体含水率变化以获取渗流场信息,通过应变片测量隧洞的应力应变响应。随着渗漏量的积累,土体含水率先上升后达到稳定,而应变与沉降持续增长。渗漏对沉降产生影响的土体局限在一定范围内,沉降影响区增长速度随渗漏积累逐渐放缓。初期影响区形状呈现倒锥形。随着渗漏量的增大,影响区基本充满隧洞上部并扩散至下部,影响区的面积在隧道下部增长缓慢,且边界面接近水平。土体的不均匀沉降导致临近的隧洞产生弯矩,弯矩的增长先快后慢,与土体的沉降变化规律相近。

Underground water leakage may lead to pavement settlement,threatening the safety of surrounding soil and adjacent structures.The centrifugal model tests are conducted to explore the response of soil and tunnel under the underground water leakage.The seepage field information is obtained by measuring change of water content of soil,and the stress-strain response of the tunnel is measured by strain gauges.With the accumulation of leakage,the water content of soil first increases and then stabilizes,while the strain and settlement continue to increase.The effects of leakage on settlement are limited to a certain range,and the growth rate of the settlement-affected area gradually slows down with the accumulation of leakage.The shape of the initial settlement-affected area is inverted cone-shaped.With the increase of leakage,the settlement-affected area basically fills the upper part of the tunnel and spreads to the lower part,and the area of the settlement-affected area grows slowly in the lower part of the tunnel,and the boundary surface is close to be horizontal.The uneven soil settlement generates the bending moment in the tunnel.The development of the bending moment is first fast and then slow,which is similar to the development of settlement of soil.