In order to improve the utilization of high liquid limit soil, the fundamental properties of high liquid limit soil and its direct utilization method are studied in this paper. This work involves both laboratory and fieldwork experiments. The results show that clay and sandy clay both with high liquid limit can be directly used for the road embankment, and the degree of compaction can be controlled at 88 %. The pack-and-cover method in accordance with Chinese technical specifications is recommended to be operated in the engineering practice. The packed height should be less than 8 meters and the total height of embankment no more than 12 meters in the interests of settlement. From the view of stability, the optimal thickness value of top sealing soil layer and edge sealing soil layer is about 1.5 meter respectively, and the geogrid reinforcement spacing should be about 2.0 meters. In addition, based on Yun-Luo expressway in China filled with high liquid limit soil, the construction techniques and key points of quality control in subgrade with pack-and-cover method are compared and discussed in detail, and the feasibility of these schemes are verified by the experimental results.

The purpose of this paper is to improve the intelligence and universality of classical method for gating control in the SCOOT system. Firstly, we introduce a method to identify spillovers, and use the occupancy threshold for spillover recognition to trigger this special control logic. Then we present an influence rate model for links upstream of the bottleneck link, and a share ratio model for the downstream links, after analyzing the interrelationship of the traffic flows among adjacent traffic links. With known threshold values for the influence rate and share ratio, we propose a rule and process for selecting the intersections that should be included in the sub-area of the gating control. Thirdly, we determine total capacity adjustments for the incoming and outgoing streams of bottleneck links, with the aim of dissipating the queue to a permissible length within a given period of time. After that, the apportion models for the total adjustments among different paths and links are presented, along with the correlation coefficients of the traffic flows between the bottleneck link and the other links. Next, we ascertain the capacity decrements and increments for the gated and benefiting streams, and define the optimization schemes so as to calculate splits for the gated and benefiting intersections. Finally, we evaluate the advanced method using a VISSIM simulation. The results show that new control method brings significant and positive effects to the bottleneck link itself and to the entire control area.