This article describes the behavior of a talus-colluvium deposit up to 70-m thick located in the Serra dos Orgaos, Rio de Janeiro/RJ, Brazil. The monitoring dataset of 13 years contributes to a better understanding of the mechanisms of movement associated with talus-colluvium deposits in Southeast Brazil. The study site has had a long history of slow movements, beginning in the 1970s. Field investigations, laboratory tests, monitoring, and theoretical analyses were carried out. In total, 446 groundwater-monitoring campaigns, 120 inclinometer readings, and full-time pluviometric monitoring were completed. Creep movement has been observed with a seasonality that is controlled by variations in the groundwater table (GWT). Due to the large strains, the soil residual shear strength may be mobilized at the failure surface. Analyses indicate that a better slope stability condition may be achieved by reducing the GWT level. The installation of deep horizontal drains (DHDs) led to reductions in the GWT and movement. The displacement rate decreased from 20 mm/month to 2.5 mm/year. Moreover, the monitoring data and analyses evidence the decrease of stability of the talus-colluvium mass with increased GWT and reactivation of movement with blocked drains. Good correlations (r² up to 0.90) were observed for rainfall, movements, GWT levels, and piezometer readings. Before the installation of the DHDs, there was a direct correlation between displacements and piezometric levels. After that, this correlation was not so evident. The response of the deposit to rainfall is no longer immediate but depends on a significant amount of accumulated rainfall.

本文介绍了位于巴西里约热内卢/ RJ的Serra dos Orgaos的厚达70 m的距骨-砂砾层沉积物的行为。13年的监测数据集有助于更好地了解与巴西东南部距骨-砂砾层沉积物相关的运动机制。自1970年代开始，该研究场所就一直有缓慢的运动历史。进行了现场调查，实验室测试，监测和理论分析。总共完成了446次地下水监测活动，120次测斜仪读数和全时测雨量监测。蠕变运动的季节受到地下水位（GWT）变化的控制。由于应变大，土壤残余抗剪强度可能会在破坏面处移动。分析表明，可以通过降低GWT水平来获得更好的边坡稳定性条件。深水平排水管（DHD）的安装导致GWT和移动量的减少。位移速率从20毫米/月降低到2.5毫米/年。此外，监测数据和分析结果表明，随着GWT的增加，距骨-丘疹团块的稳定性降低，并且引流管堵塞，活动恢复。良好的相关性（降雨，运动，GWT水平和压力计读数观察到r ²高达0.90）。在安装DHD之前，位移和测压水平之间存在直接的相关性。此后，这种相关性就不那么明显了。沉积物对降雨的响应不再是立即的，而是取决于大量的累积降雨。