One of them is the k-q model, called the “Uzan-Witczak model”, which describes the resilient modulus, characteristic for varying confining pressure.

后面的characteristic for varying confining pressure是什么成分啊，修飾的哪個，這句話整體又該如何講解呢?

One of them is the k-q model, called the “Uzan-Witczak model”, which describes the resilient modulus, characteristic for varying confining pressure.

【翻譯】其中之一是k-q模型，稱為“UZAN-Witczak模型”，此模型描述了具備不同圍壓變化特點的回彈模量。

characteristic for varying confining pressure，是形容詞短語作定語，修飾the resilient modulus，意為“具備某種特點的某事物”。characteristic 之前的逗號是多余的，刪去。