The highway BR 163 near the city Nobres, Mato Grosso State in Brazil has slopes with falling arenite blocks (fig. 1). The solution to this problem was a metallic mesh with a patterned of anchors. The software MACRO 1, from Maccaferri, was used to design the system. A secured drapery system, consisting of rockfall netting and a systematic nailing scheme, is designed to stabilize surficial material on an exposed rock face. The design procedure can be very complicated because the geomechanical models are very complex or unrealistic, and obtaining accurate input data is rather problematic. This paper presents a simple design approach for secured drapery system, which combines the field experience of geologists and engineers on one hand, and the results of full scale drapery field tests on the other.

1. Introduction

The section under consideration is between km 39 + 020 and km 39 + 080, the duplication of the BR-163 in the city of Noble-MT (Figure 1). Was observed on their visit on 27 and 28 February and 27 November 2013 the occurrence of sandstone blocks drops with different sizes, some reaching over 1.00 meters in diameter on the shoulder of the duplicate track. Photos 2 and 3 shows the slope basically composed of friable sandstone layers from 0.30 to 1.00 meters horizontal layers and also with various dips, are also found fault planes towards the foot the slope (photo 3). Photo 4 shows block falls on November 27, 2013.

After the construction of BR 163 Highway near the city of Nobres, Mato Grosso State in Brazil (fig 1) blocks of arenite rock began to fall in the road.

There are four situations to consider about rock slopes subject to falling blocks. Should be set according to various alternative technical complexities and the level of danger. The first possibility is to eliminate the problem causing the instability, if this stretch removal of the element (the sandstone blocks) until a stable slope is reached. In this case it would be done by blasting the rock.

This content is only available via PDF.
You can access this article if you purchase or spend a download.