Other Civil and Environmental Engineering Commons^™

Skid Resistance Detection Technology Of Highway Pavement Based On Tie‑Pavement Coupling Noise, Ye Wei, Chen Fei, Hu Xiaoyang, Xu Zhengwei, Li Liguo

Journal of China & Foreign Highway

In order to improve the skid resistance detection technology of highway pavement，this paper summarized the advantages and disadvantages of the traditional pavement noise measurement methods，adopted the vehicle-following method to collect the tie-pavement coupling noise，and optimized the specific positional parameters of the microphone.The speed correction of the equivalent continuous A-weighted sound level was realized through the fitting of driving speed and equivalent continuous A-weighted sound level.The characteristic signal of the tie-pavement coupling noise was extracted by the principal component analysis method，and it can effectively suppress interference signals such as traffic noise，wind noise，and engine noise.The envelope noise energy （ENE） was obtained by …

Effect Of Corn Stover Oil On Rheological Properties Of Aged Asphalt And Its Regeneration Effect, Cheng Peifeng, Bai Yue, Li Yiming, Zhang Zhanming

Journal of China & Foreign Highway

Corn stover oil，as a kind of bio-oil，is low-carbon and renewable.At the same time，it may restore the performance of aged asphalt.In order to further promote the application of corn stover oil in road engineering，this study explored the effect of corn stover oil as a kind of regeneration agent on the rheological properties of aged asphalt through laboratory experiments and analyzed the regeneration effect.On this basis，the regeneration mechanism of corn stover oil regeneration agent was revealed by using an infrared spectroscopy test and gel permeation chromatography test.The results show that the addition of corn stover oil changes the proportion of aged asphalt …

Research And Practice On Demolition Of Lane Separator In Same Direction Along Zhengzhou‒Luoyang Section Of Lianyungang‒Khorgos Expressway, Zhang Nan, Ji Xiang, Ma Gang

Journal of China & Foreign Highway

In order to solve the problem arising after the demolition and closure of the lane separator in the same direction along the expressway，this paper systematically introduced the reconstruction method of the lane separator in the same direction by studying the overhaul project along Zhengzhou-Luoyang section of Lianyungang‒Khorgos Expressway.The paper explored the main diseases and potential safety hazards existing in the lane separator in the same direction by checking the compliance of specifications，analyzing the traffic operation status，exploring the characteristics of traffic accidents，and investigating the traffic safety facilities.On this basis，it demonstrated the feasibility of demolishing the lane separator in the same direction.According …

Mechanical Properties Of Alkali‑Activated Slag‑Fly Ash Geopolymers, Liu Yang, Wang Jizhao, Lu Naiwei, Wang Bowen

Journal of China & Foreign Highway

In order to respond to the national strategy of energy saving and emission reduction and improve the comprehensive utilization rate of industrial waste，the influence of slag content，alkali equivalent，sodium silicate modulus，and water-cement ratio on the compressive strength of slag-fly ash geopolymers was investigated by single variable and orthogonal experiment method.The compressive strength of geopolymers was analyzed by combining XRD，SEM，and porosity.The results show that the gel formation is promoted with the increase in slag content，and the structure of geopolymers is more compact，which is conducive to the development of strength.After 28 days of standard curing，the influence of various factors on the compressive strength …

Mechanical Properties Of Geopolymer‑Stabilized Recycled Aggregates From Construction Solid Wastes, Yuan Kaixin, He Yongjian, Zhang Laijun, Li Hai, Xu Gewei

Journal of China & Foreign Highway

In order to solve the problem of a sharp increase in construction solid wastes and insufficient utilization rate，this paper took slag-fly ash-based geopolymer as an inorganic binder，replaced natural gravels with recycled aggregates from construction solid wastes，and set urban road base layer as the target scene to study the mechanical properties of geopolymer-stabilized recycled aggregates at different contents.The results show that with the increase in geopolymer content，the maximum dry density of the mixture increases.The optimum moisture content increases.The unconfined compressive strength of the mixture increases with the increase in geopolymer content and curing age and decreases with the increase in recycled …

Comparative Experimental Study On Deformation Characteristics Of High Liquid Limit Soil Under Different Dry And Wet States, Qin Lingwei, Zhang Rui, Li Lu, Xiao Yupeng

Journal of China & Foreign Highway

In order to further reveal the internal mechanism of the influence of solid-like bound water on the deformation characteristics of high liquid limit soil，the difference in the influence of different bound water contents on the deformation of soil samples was analyzed through the comparison of dry and wet sides.Four types of high liquid limit soil with different water contents at the same dry density were used，and a low liquid limit soil was used as a comparison sample to carry out a deformation test.The volumetric flask method was used to test the content of adsorbed bound water in each test soil …

Influence Of Loading Methods On Compression Modulus Of Red Sandstone Soil Solidified With Biological Enzyme And Cement, He Liang, Zhang Haixiang, Guan H Ongxin, Li Huili, Yang Hairong, Liu Hongfu

Journal of China & Foreign Highway

There are various methods to test the modulus of cement-stabilized mixtures.The stiffness performance of cement-stabilized materials will be affected after adding biological enzymes.In order to systematically analyze the influence of loading conditions on the compression modulus of the red sandstone soil solidified with biological enzyme and cement，compressive modulus tests were conducted on the red sandstone soil solidified with biological enzyme and cement by using three static modulus test methods including monotonic loading method of middle section，stepwise loading and unloading method of top surface，and stepwise loading and unloading method of middle section，as well as dynamic modulus method of top surface and …

Optimization Of Mix Proportion For New Jersey Precast Concrete Safety Barriers And Performance Tests Under Integral Concrete Vibrating, Chen Lin, Li Beian, Li Yuanrui, Zhao Zixiang

Journal of China & Foreign Highway

New Jersey safety barriers are the most commonly used form of guardrails in highway median separators due to their excellent safety protection.In response to the cost reduction and quality improvement，efficient and rapid preparation process，and quality issues of New Jersey precast concrete safety barriers，this article adopted the automation production process of New Jersey precast safety barriers，optimized concrete mix proportion for precast safety barriers，and studied their performance.The experimental results show that in the designed C 30 concrete，the compressive strength of the concrete mixed with 15% fly ash reaches 39.2 MPa，and th e slump reaches 185 mm.The concrete performance meets the requirements of …

Experimental Study On Shear Behavior Between Nrc‑Uhpc Interface, Chen Zhenkan, Li Junsheng, Shi Quan, Fang Haozhen, Mo Fan, Jiang Haibo

Journal of China & Foreign Highway

In order to investigate the effect of the screw diameter of planted bars and ultra-high performance concrete （UHPC） pouring method on the shear behavior of normal reinforced concrete （NRC） and UHPC， two groups of six push-out specimens were designed for shear behavior tests.The results show that after the failure of the concrete bonding force in the NRC-UHPC interface，the screw can maintain shear behavior so that the failure process of the specimen after the load reaches the peak shows ductile characteristics.For specimens with screw diameters of 12 mm and 16 mm，greater screw diameter indicates higher shear capacity of the specimens and …

Design And Construction Process Of Cross‑Beam Supports For Main Tower Of Changtai Changjiang River Bridge, Zeng Jian, Hu Pei, Wang Chao

Journal of China & Foreign Highway

The construction of the lower cross-beam structure of the main tower of Changtai Changjiang River Bridge has the characteristics of high construction height，large amount of concrete earth volume，and difficult control of down-warping deformation.In order to implement the pouring of the lower cross-beam of the main tower，floor-type steel pipe supports were set at the lower cross-beam，which were used to support the lower cross-beam formwork and bear the load during the concrete pouring.Through the finite element software analysis and calculation，it was found that the asymmetric deformation of the main structure of the lower cross-beam could be effectively controlled，and the overall force of …

Determination Of Manufacturing Parameters Of Large Section Of Continuous Steel Box Beam With Variable Section In Shenzhen‑Zhongshan Passage, Dong Chuangwen, Chen Long, Li Chuanxi

Journal of China & Foreign Highway

Accurate calculation of manufacturing parameters is the key to the efficient，high-precision，and rapid installation of large sections of continuous steel box beam bridges.Taking the steel box beam with the variable section in Shenzhen-Zhongshan Passage as the background，this paper first established a finite element model of the beam element in the whole construction process to obtain the pre-camper.Secondly，the average neutral axis position was calculated based on the height of the neutral axis of each beam section.Then，according to the deformation characteristic that the beam length remained unchanged at the mean neutral axis，the pre-camber was superimposed at the mean neutral axis to get the …

Key Technology For Construction Of New Single‑Wall Steel Suspended Box Cofferdam With High Pile Tied Beams In Deep Water, Yang Jinlong, Zhao Lin, Jiang Qunlong

Journal of China & Foreign Highway

In order to ensure the safe，efficient，and economical completion of the construction of the high pile tied beam of Muping Xiangjiang River Bridge in deep water，a new type of single-wall steel suspended box cofferdam was designed to act as the water retaining and enclosure structure during high pile tied beam construction according to the characteristics of deep water level and shallow stratum cover layer at the high pile tied beam location.Through the innovative design of steel casing on the bottom of the steel suspended box cofferdam，the design height of the wall panel and the amount of steel input were reduced.On the …

Influence Factors Of Carbonization Of Tunnel Segment Structure And Life Prediction Analysis, Li Dongbiao, Miao Miao, Shen Caihua, Chen Wei

Journal of China & Foreign Highway

There are many factors that affect the carbonization life of concrete segments in underwater tunnels，and the prediction methods are not uniform.In this paper，combined with actual engineering，the influencing factors and laws of carbonization of concrete segments in underwater tunnels were analyzed，and three methods for predicting the life of concrete segments were established with the crack limit as the control target.The prediction results of the three methods were compared.The results show that the influence of the temperature and CO2 concentration in the tunnel predicted by the three methods on the life of the tunnel lining structure is basically consistent with the existing …

Key Technology For Incremental Launching Construction Of Double Guide Beam Of Steel Box Girder, Sun Xiaoqiang, Yue Xinxing

Journal of China & Foreign Highway

By taking the incremental launching construction of the steel box girder at the 6th hole of the approach bridge of Baoji Taigu Bridge as the engineering background，the original plan adopted single-guide beam multi-point walking incremental launching technology for assembly and incremental launching on the prestressed reinforced concrete beam of the adjacent hole.Since the middle span of the concrete beam cannot withstand the concentrated force at the incremental launching points，the multi-guide beam multi-point walking incremental launching technology was finally used to arrange the incremental launching points at the transverse diaphragm plate of the end of the concrete beam.By increasing the incremental …

Emergency Vehicle Dispatching Model Considering Demand Urgency And Delivery Fairness, Long Kejun, Liu Jia, Gao Zhibo, Chen Suqian, Zhang Zhonggen

Journal of China & Foreign Highway

In emergency vehicle dispatching after unexpected events，it is crucial to prioritize critical nodes with high demand urgency while minimizing excessive delivery delays at other nodes to prevent secondary impacts.On this basis，this study developed an emergency vehicle dispatching model that considered demand urgency and delivery delay fairness.Firstly，the entropy weight-TOPSIS method was used to calculate the demand urgency for each node，and a delivery delay balance index was introduced to minimize disparities in delivery delays between nodes.Secondly，a multi-objective optimization model was established with total delivery time，overall cost，and delivery delay balance as objectives，while considering constraints such as inventory levels at distribution centers and route …

Working Properties Of Steel Tube Batter Piles With Concrete Infill Based On Abaqus, Yang Meiliang, Li Liemin, Sun Kunjiang, Han Rui, Zhong Yang

Journal of China & Foreign Highway

In order to explore the respons e characteristics of steel tube batter piles with concrete infill under vertical load，the steel tube batter pile with concrete infill used in Saribas Bridge in Malaysia was taken as the research object.Based on the numerical simulation method，the frictional resistance of the inner and outer walls of the steel tube，the frictional resistance around the pile at the section，and the bending moment bearing ratio between the steel tube and the concrete core of this type of batter pile under vertical load were studied.The results show that the passive-side frictional resistance of the 0–15 m pile section …

Impacts Of Stream Bed Adjustment On Local Bridge Morphology At Highway 281, Molly G. Likins

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nebraska sand-bed rivers have long been a part of sediment transport studies and have been used in the development of numerous well-known empirical bedload equations. Some of these studies have shown how adjustments in streambed elevation led to changes in local stream morphology. The sand-bed rivers of Nebraska are highly susceptible to such changes due to their wide, shallow cross-sections and erodibility. The objective of our study is to synthesize a hydrodynamic model with high-resolution field data and improved methods of representing sediment transport to better predict both short and long-term channel adjustments for an aggraded sand-bed river.

The field …

Development And Evaluation Of Highly Thixotropic Uhpc Mixtures For Bridge Overlay Applications, Akbota Aitbayeva

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Ultra-high-performance concrete (UHPC) is an advanced construction material renowned for its exceptional strength and durability. However, conventional UHPC is typically self-consolidating, making it unsuitable for bridge deck overlay applications due to challenges posed by potential surface slopes. UHPC overlay construction requires a highly thixotropic material that not only responds well to vibration but also maintains workability over an extended period and remains stable on sloped surfaces. Despite the complex rheological properties of highly thixotropic UHPC, limited testing methods are available to effectively assess the workability and rheology of overlay mixtures. To address this gap, the present study provides a comprehensive …

Exploring Variably Saturated Flow Formulations For Modflow: Implementing A Fully 3d Richards' Equation In Modflow 6, Sebastian Vazquez-Gasty

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis explores the implementation of a fully 3D Richards’ equation solution into MODFLOW 6 to solve for saturated/unsaturated flow. Currently, MODFLOW 6 has limited capability for solving unsaturated zone flow problems by using the Unsaturated Zone Flow (UZF) package, which neglects capillarity and assumes vertical 1-dimensional flow. Various formulations of the Richards’ equation were first evaluated for their strengths and weaknesses. Various numerical solution approaches to Richards’ equation were also studied to understand the robustness and efficiency of different approaches and to select one that would best fit into the MODFLOW 6 framework. The MODFLOW 6 framework was also …

Numerical Study On The Behavior Of Natural And Recycled Aggregate Concretes, Shahriar Mardpour

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis investigates the mechanical behavior of natural and recycled aggregate concretes (NAC and RAC) using a multi-phase numerical approach to predict performance. Growing interest in sustainable materials has led to using recycled concrete aggregates (RCA) to replace natural aggregates, creating Recycled Aggregate Concrete (RAC). Due to their different structural components, RAC and NAC exhibit varying mechanical properties, particularly in strength and durability.

This study validated tension and bending (flexural) test models by comparing numerical results with similar models from the literature. Following validation, a multi-phase approach modeled NAC and RAC for the bending (flexural) and tension tests, providing a …