采用contact pair, tied 时出现的错误,碰到过的大虾指点下

windsun.typ

如题，模拟基坑开挖，有地下水的作用，地墙与土体之间采用contact pair, tied这种类型的接触(注意不是*tie约束类型)
inp文件中的语句如下：
···········
···········
** Interaction: conwall-LL
*Contact Pair, interaction=wallsoil-tied, adjust=conwall-LL-node, tied
conwall-LL-node_CNS_, conwall-LL
···········
···········
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计算不能进行，dat文件中出现了如下的错误提示：
***error: surface interaction wallsoil-tied can be used only to define
           interaction between surfaces having coupled pore
           pressure-displacement underlying elements. use two different surface
           interaction names
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试了半天没搞定这个错误，请问下有碰到过这个问题的大虾，该如何解决。谢谢~~