A procedure to estimate the lateral force in clay-pipe interaction after breakout

The development of new offshore oil and gas fields is continuously expanding to ultra-deep waters. This tendency and the necessity of reducing project costs have been stimulating the development of new technologies as well as the enhancement of floating production systems. In this regard, pipelines and flexible riser systems have been getting more attention due to its low cost of installation and operation. In order to project a pipeline system, it is important to understand the pipe-soil interaction mechanisms and quantify the influence of soil behaviour on pipe response caused by lateral movement such as thermal buckling. The loads that a pipeline is subjected have been a topic of many experimental studies that aim to reproduce those loads in a realistic manner. This present study concerns the analysis of lateral clay-pipe interaction associated with large deformations and berm formation process at the leading edge of the pipe during movement at given burial depths. A series of centrifuge tests was conducted to assess the relationship between horizontal force and lateral pipe displacement. The breakout force experimental results were compared with different literature proposals, showing a good agreement. A procedure was also proposed to evaluate the normalized lateral force through the combination of two different approaches. The results showed a good comparison with the centrifuge experimental data.

Two Types of Smoking Pipes and a Global Perspective in Rua do Terreiro do Trigo, Lisbon

Studies of clay smoking pipes represent one of the major fields of research in post-medieval archaeology due to their frequent occurrence in the archaeological record and their suitability for typological dating. During an archaeological survey in Rua do Terreiro do Trigo, located in Lisbon’s picturesque district of Alfama, very close to the Tagus River and where many different and cosmopolitan people spent their spare time during the post-medieval period, we were able to collect a significant number of smoking pipes fragments, given the site’s dimension. Amongst the sherds recovered it is possible to identify a great number of European kaolin clay pipe fragments dated from the 17th to the 18th century and also a set of unusual black and grey earthenware chibouks of (yet) uncertain origin. Therefore, this paper seeks to report the smoking pipe assemblage recovered in Rua do Terreiro do Trigo, but also to discuss the study of smoking devices in the Portuguese post-medieval archaeological contexts.

Statistical analysis of sewer odour based on 10-year complaint data

The City of Edmonton has been suffering from sewer odour problem for many years. Ten years of odour complaints data from 2008 to 2017 were statistically analyzed to identify major factors that relate to the odour problem. Spatial and temporal distributions of odour complaints in the city were first presented. Then relationships between the complaints and physical attributes of the sewer systems were analyzed by introducing a parameter of risk index. It was found that the snowmelt and storm events could possibly reduce odour complaints. Old sewer pipes and large drop structures are statistically more linked and thus significantly contribute to the complaints. The risk index relationship for three pipe materials is clay pipe > concrete pipe > PVC pipe. Combined sewers are more problematic in terms of odour complaints than sanitary sewers. And no clear correlation has been found between the changes of sewer pipe slope or angle and the complaints.