用摩擦-接触耦合结点计算挡土墙压力

Friction-Contact Coupled Nodals for Calculating Rataining Earth Pressure

本文分析了挡土墙上静土压力分布形式、墙体位移形式对土压力的影响等问题.应用摩察-接触耦合结点(FCCN)模拟不同介质间的接触问题,结果表明:该方法具有概念清晰和使用方便等优点.主要结论:1.本方法计算结果与应用库伦主动土压力理论计算的土压力合力值基本接近,但合力作用点应在墙高的下1/5左右,并且随填土摩擦角的不同而变.土压力分布具有非线性分布规律;2.被动土压力大小、分布没有固定形式而取决于墙体的位移形式和受力状态,并且认为,通常被动土压力值远达不到朗肯或库伦计算的量值,因此实际工程中不宜采用库伦或朗肯被动土压力理论.

In this paper, the distribution of earth pressure on retaining walls and effect of wall displacement patterns on earth pressure are discussed. The method of friction-contact coupled nodals (FCCN) is used to simulate the contact problem and it has the advantages of being clear in concept and convenient. It is found that the active earth pressure given by Coulomb Theory approaches that obtained by the method of FCCN, while the thrust acts at a distance of H (wall height)/5 above the bottom in the latter case. With equal wall height, the thrust acts higher with increase of ?. It is also found that the distribution of active earth pressure is non-linear. The magnitude and distribution of passive earth pressure also depend on the wall displacement pattern and loading state. There is no fixed distribution. In the service State, the earth pressure on retaining walls usually does not reach either the Rankine value or Coulomb value. Therefore, it is inappropriate to adopt Rankine or Coulomb passiveearth pressure values in engineering practice.