基于加筋路基中筋材应力性状的土工格室改进铺设方法

确定土工格室加筋路基中筋材内部的应力性状是控制工程成本、有效发挥土工格室加筋作用的关键因素。首先通过室内试验确定高强土工格室材料的应力-应变关系并以此确定其本构模型,而后基于ABAQUS有限元软件,采用分离式分析法分别建立土工格室及路基的计算模型,对多层土工格室加筋路基进行有限元分析。通过添加土工格室前后情况对比,改变土工格室的加筋层数进行分析,研究不同铺设层数的土工格室对路基沉降及侧向位移的影响。通过分析多层土工格室加筋路基内部筋材的拉应力性状,提出一种改进的铺设方法,并建立了有限元模型进行验证。结果表明:添加土工格室能够有效限制路基沉降及侧向位移,使路基的整体稳定性得到提高,具体表现为铺设1层土工格室时,路基中线处的竖向位移可减小36.2%,坡脚处的水平位移可减小74.8%,且路基的稳定性与土工格室铺设层数呈正相关。土工格室筋材内部拉应力由路基中线向路基两侧呈逐渐减小的趋势,在路基边缘位置已趋于零。采用多层土工格室加筋时,最底层的土工格室和最上层的土工格室承受较大的拉应力。在此规律的基础上,采用改进的土工格室铺设方法,在最大节约30%筋材的前提下,可取得大致相同的加筋效果。

Improved laying method of geocell based on stress behavior of reinforcement in reinforced roadbed

Determining the internal stress properties of the reinforcement in the geocell reinforced subgrade is a key factor to control the project cost and effectively play the role of geocell reinforcement. In this paper, the stress-strain relationship of the high-strength geocell is determined through indoor experiments and its constitutive model is determined based on this. Then, based on the ABAQUS finite element software, the calculation models of the geocell and the embankment are established separately by the separation analysis method. Carry out finite element analysis on the embankment reinforced by geocells. By comparing the conditions before and after adding the geocells, the number of reinforced layers of the geocells is changed for analysis, and the influence of the geocells with different paving layers on the settlement and lateral displacement of the embankment is studied. By analyzing the tensile stress properties of the internal reinforcement of the multi-layer geocell reinforced embankment, an improved laying method was proposed and a finite element model was established for verification. The results show that the addition of geocells can effectively limit the settlement and lateral displacement of the embankment, and improve the overall stability of the embankment. Specifically, when a layer of geocell is laid, the vertical displacement at the center line of the subgrade can be reduced by 36.2%. The horizontal displacement at the toe of the slope can be reduced by 74.8%, and the stability of the embankment is positively correlated with the number of layers of the geocell. The internal tensile stress of the geocell reinforcement gradually decreases from the center line of the embankment to both sides of the embankment, and it has tended to zero at the edge of the embankment. When using multi-layer geocells to reinforce, the bottom geocell and the top geocell bear greater tensile stress. On the basis of this rule, the improved geocell paving method is adopted to achieve roughly the same reinforcement effect under the premise of maximum saving of 30% of the reinforcement.