Bridge Foundations Research Articles

Study on the position of load box for pile foundation of Qilu Yellow River Approach Bridge

In theory, the balance point position of O-cell pile test is determined and unique, and the load box should be located at this point. But in practical projects, it is difficult to determine the balance point position accurately. The pile foundation of Qilu Yellow River Approach Bridge bears a large load. In order to reduce the risk caused by the position of load box in O-cell pile test, the double load box technology is adopted in this pile test project. According to the pile design, the soil properties and the loading sequence, the bearing capacity of the pile foundation before and after grouting is estimated. The pile test results show that the project is a successful example for the double load box technology.

Geotechnical monitoring bearing capacity boring pile foundations of bridge during permafrost degradation

The construction and operation of bridge foundations in permafrost conditions is associated with many problems, the most urgent of which is the degradation of the frozen state of soils due to the effect of solar radiation on the thawing process. Thawing of permafrost soils of the base significantly affects structures, the design of which does not provide for thorough protection from natural factors - first of all, these are railway bridges. The changing climate has a destructive effect on permafrost soils, which is destructive for infrastructure facilities operated in the permafrost zone. The aim of the given work is to increase the efficiency of systems that regulate the temperature regime of permafrost soils of the bridges foundations which are located on railways in permafrost regions.

Determination of additional load on the bridge foundation pile under karst deformation

It is necessary to assess the additional loads transferred to the piles during the growth of a karst cavity in karst soils for designing bridge support pile foundations in karst areas. Additional loads arise due to the displacement of the soil mass above the cavity and the emergence of “negative friction” forces on the pile lateral surface. The paper proposes a method for determining the additional load on the pile depending on the distance from the pile bottom to the karst soil roof and the predicted diameter of the cavity in karst soils. A method for numerical variation calculations based on the analysis of the change of shear stresses on the pile lateral surface at different stages of loading with the growth of a cavity and the stable arch over the cavity is proposed. The correct design model and criteria for stability evaluation of the arch over the cavity are selected. A series of numerical calculations are made. An analytical solution to determine the additional load on the pile depending on the distance from the pile bottom to the karst soil roof and the predicted diameter of the cavity in karst soils is obtained.

Performance of Impulse Response Testing on Prismatic Members with Intermediate Joints

Nondestructive Testing (NDT) methods have extensively been used to assess the conditions of civil infrastructure in the recent decades. Among various NDT techniques, Impulse Response (IR) has a vast application due to its simplicity and low cost. However, factors such as reflections from changes in impedance along the investigated members can adversely influence the success of the method. Numerous numerical and experimental studies have already been performed to evaluate the effect of change in mechanical impedances such as bulging, necking and similar anomalies. In this study, the effect of the presence of joints connecting the investigated members to other members, as another source of impedance change, is demonstrated. A three-story steel-concrete composite column of a building was selected for testing and IR tests were conducted. The obtained mobility graphs were clear, and the height of the column was easily measured with an acceptable error. The results of this study show that although the joints located between the top and bottom of the tested member are sources of change in mechanical impedance, they do not result in concealing the resonant frequencies from the wave reflected from the bottom of the member. Thus, IR method seems to be applicable in determining the length of prismatic members with intermediate joints such as piles of unknown bridge foundations with bracing and columns of buried buildings.

Analysis of abutment safety factors against landslides on the Cipeundeuy bridge - Sukatani, Indonesia

Bridges are connecting access between one region and another, and play an important role in transportation to facilitate community economic activities. The river bridge has very steep cliffs, and these cliffs often occur in landslides, therefore this study is very important to determine the safety of the bridge. This study aims to determine the safety of the bridge abutment structure which is the head of the bridge with the function of continuing the load on the bridge foundation. This analysis is limited to only calculating the stability and safety of bridge abutments with reinforced concrete structures. The analysis uses methods and formulas referring to Indonesian national standards, namely RSNI T-02-2005 regarding loading for bridges, RSNI T-12-2004 concerning concrete structure planning for bridges, SNI 03-2833-200X concerning earthquake resistance planning standards for bridges. The data used are drawing data and technical specifications used on the bridge, then the data is verified against planning consultants, project implementers, and observations at the location. The results of the analysis stated that the bridge abutment was declared safe from soil thrust and other forces, but did not have a good safety factor against shear forces. Landslides that occur can be resisted by the bridge abutments. This research is expected to be followed up by policymakers to repair bridges so that they are resistant to maximum shear forces, and provide safety signs from landslides to relieve public anxiety when crossing bridges, as well as provide reinforcement for the cliffs around the bridge.

Costs, incentives, and institutions in bridging evolutionary economic geography and global production networks

ABSTRACT Two of the most influential strands in economic geography and regional studies – evolutionary economic geography and global production networks – have run on parallel tracks with limited cross-fertilization. The Regional Studies Annual Lecture 2020 paper by Henry Yeung proposes building bridges across both strands to improve our understanding of the uneven distribution and evolution of economic activity across the world. He puts forward the concept of strategic coupling as the foundation of such bridges. In this reply I argue that strategic coupling will not suffice, unless the variations in costs and incentives for engaging in networks and the different capacity of cities and regions to assimilate the benefits of innovation diffusion through networks are taken into consideration.

Effect of V-shape canyon topography on seismic response of deep-water rigid-frame bridge based on simulated ground motions

Deep-water bridges located in a V-shape canyon may suffer from spatially varying ground motions due to the canyon topography. This paper focused on the effect of canyon topography on the seismic responses of a deep-water continuous rigid-frame bridge that crosses a V-shape canyon. The ground motions in three example sites with different topography conditions were simulated by the numerical spectral element method. A database with one hundred point-sources considering the uncertainties of seismic magnitude and source location was sampled and adopted to simulate the seismic waves propagating from the source to the bridge site. Nonlinear seismic response analyses of the example deep-water bridge were performed under the simulated spatially varying ground motions considering the hydrodynamic added mass on the piers. The effects of the canyon topography on the seismic wave field, peak ground acceleration at bridge foundations, and seismic responses of the bridge were analyzed. According to the example studies, the canyon topography induces a significant spatial variation of the ground motions for the bridge in the canyon. Compared with the canyon topography, the influence of water within the canyon on the ground motion is slight. Neglecting the effect of canyon topography leads to the inappropriate assessment of the seismic fragility of the deep-water bridge in both component and system levels.

Progressive Failure Analysis of Slope Water Damage Based on Improved Green-Ampt Infiltration Model

In order to get the law of rainwater infiltration and the law of progressive water damage, the slope of Tianshang bridge foundation in Yunnan Province of China is taken as the engineering basis. The site investigation of the damaged slope is carried out. The traditional Green-Ampt model is improved by considering the ponding effect of dynamic water flow on the slope surface. Based on the variation characteristics of wetting front obtained by the improved infiltration model, the progressive failure process of slope with continuous infiltration is simulated by FLAC3D software. The results show that the water damage of Tianshang bridge slope is mainly caused by the slope absorbing a lot of rainwater in a short time, which has obvious time discontinuity characteristics in time, and shows obvious multi-layer progressive failure characteristics in failure space. The wetting front characteristics obtained by the improved Green-Ampt infiltration model are more consistent with the engineering practice. The water accumulation effect of surface water gradually weakens with the increase of the wet front depth. The slope failure develops gradually from the toe to the top and from shallow to deep. The intermittent failure characteristics provide surplus time for the engineering treatment, the gravel soil slope should be treated after a small-scale water damage occurs.

Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic hierarchy process and finite element method

Many uncertain factors in the excavation process may lead to excessive lateral displacement or overlimited internal force of the piles, as well as inordinate settlement of soil surrounding the existing bridge foundation. Safety control is pivotal to ensuring the safety of adjacent structures. In this paper, an innovative method is proposed that combines an analytic hierarchy process (AHP) with a finite element method (FEM) to reveal the potential impact risk of uncertain factors on the surrounding environment. The AHP was adopted to determine key influencing factors based on the weight of each influencing factor. The FEM was used to quantify the impact of the key influencing factors on the surrounding environment. In terms of the AHP, the index system of uncertain factors was established based on an engineering investigation. A matrix comparing the lower index layer to the upper index layer, and the weight of each influencing factor, were calculated. It was found that the excavation depth and the distance between the foundation pit and the bridge foundation were fundamental factors. For the FEM, the FE baseline model was calibrated based on the case of no bridge surrounding the foundation pit. The consistency between the monitoring data and the numerical simulation data for a ground settlement was analyzed. FE simulations were then conducted to quantitatively analyze the degree of influence of the key influencing factors on the bridge foundation. Furthermore, the lateral displacement of the bridge pile foundation, the internal force of the piles, and the settlement of the soil surrounding the pile foundation were emphatically analyzed. The most hazardous construction condition was also determined. Finally, two safety control measures for increasing the numbers of support levels and the rooted depths of the enclosure structure were suggested. A novel method for combining AHP with FEM can be used to determine the key influencing aspects among many uncertain factors during a construction, which can provide some beneficial references for engineering design and construction.

Numerical analysis of the effect of underpass construction on an existing bridge foundation

Micropiles are used effectively in many ground improvement applications, such as increasing soil bearing capacity, reducing the settlement of existing foundations, strengthening existing foundations, and reducing lateral soil movement due to arching. In this research, the micropiles, a geotechnical supposed solution, have applied to maximize the benefit for all the mentioned features. The frictional resistance between the surface of micropiles and the surrounding soil is considered. Besides, the effect of the micropiles network is considered as a possible means for improvement. We have examined a case study in which micropiles of400 mm diameter and 13.00 m length were used to improve the bearing capacity of soil underlies the existing bridge foundations, reduce their settlement, and decrease the side-support system’s deformation. The models created for this study were used to simulate the proposed geotechnical solution.

Uptake and Dissemination of Multi-Criteria Decision Support Methods in Civil Engineering—Lessons from the Literature

The SCOPUS and Wed of Science bibliometric databases were searched for papers related to the use of multi-criteria methods in civil engineering related disciplines. The results were analyzed for information on the reported geographical distribution of usage, the methods used, the application areas with most usage and the software tools used. There was a wide geographical distribution of usage with all northern hemisphere continents well represented. However, of the very many methods available, a small number seemed to dominate usage, with the Analytic Hierarchy Process being the most frequently used. The application areas represented in the documents found was not widely spread and mainly seemed to be focused on issues such as sustainability, environment, risk, safety and to some extent project management, with less usage on other areas. This may be due to individual engineer’s choices in relation to if and how to disseminate the results of their work and to their choice of keywords and titles that determine if their publications are selected in bibliographic searches and thus more visible to a wider readership. A comparison with more topic focused searches, relating to Bridge Design, Earthquake Engineering, Cladding, Sewage Treatment, Foundation design, Truss design, Water Supply, Building Energy, Route selection and Transport mode showed very different results. Analysis of the papers in this area indicated that the full range of supporting software available for multi-criteria decision analysis (many listed in this paper) may not be fully appreciated by potential users.

Mitigation of Scour Failure Risk of a River Bridge Located in an Ungauged Basin

In this study, scour failure risk of the Çatalzeytin Bridge located in the Western Black Sea Basin, Turkey, was assessed for possible future flood events and appropriate scour countermeasures were considered based on economic and constructability considerations. Waterway adequacy in the spans of the bridge and scour criticality around bridge foundations considered for risk calculations in HYRISK were estimated by hydrological and hydraulic analyses of the watershed and stream. Since the watershed of the bridge is ungauged, geomorphological instantaneous unit hydrograph concept was adopted to estimate the peak discharges with various return periods to be used in hydraulic modelling. Monte Carlo simulation results indicated that most of the simulated peak discharges were in the 95% confidence interval. Hydraulic model results from HECRAS indicated that waterway adequacy and scour criticality were critical for discharges with 200 and 500-year return periods. Scour failure risk of the Çatalzeytin Bridge was classified as high and it was proposed to reduce the risk by constructing partially grouted riprap as the most feasible alternative that would consequently increase the expected lifespan of the bridge. Following this methodology, river bridges may be prioritized based on the risk analysis.

Evaluating vertical conditions of bridge substructures of heavy-haul railway lines based on dynamic stiffness and pier vibration response

When it is necessary to increase the freight volume, the related increase in the train axle loads can potentially affect the bearing capacity of bridge substructures. Therefore, the structural integrity of bridge substructures should be evaluated, and their capacities need to be estimated. Existing studies have only investigated the lateral health condition of piers and foundations of bridges. To evaluate the vertical condition of bridge substructures, in this study, a dynamic transient response method (TRM) was developed using newly designed equipment. The vertical dynamic stiffness of a bridge foundation was employed as the main evaluation index. Subsequently, in situ experiments were performed on 62 bridge foundations of a heavy-haul railway line, including three types of foundations. Train-induced vertical and lateral vibration responses on the pier tops were also measured. The relationship between the vertical dynamic stiffness of the foundations and the train-induced vibration amplitudes on the pier tops was analysed. Subsequently, the support vector machine (SVM) method was employed to predict the dynamic stiffness of the bridge foundations when the TRM test could not be performed and the train-induced vertical vibration response on pier tops could be tested. Finally, a three-step evaluation strategy was proposed to comprehensively assess the vertical conditions of bridge substructures using the above methods. The study indicates the following: (1) The redundancy of the vertical bearing capacity is completely different from that of the horizontal vibration amplitude. There may be a certain error in the evaluation of a pier foundation when only the horizontal vibration amplitude is used to analyse its health condition. (2) The dynamic stiffness obtained by the TRM can effectively reflect the vertical condition of a bridge substructure and can be employed as an index in the detailed evaluation stage. (3) Using SVM, the dynamic stiffness of a foundation can be predicted with the measured amplitudes of the train-induced vertical vibration on the pier tops. The amplitudes of train-induced vibration and SVM-based prediction of dynamic stiffness can be used as early warning indicators in the scoping evaluation stage.

EXPERIMENTAL AND NUMERICAL STUDY ON COLUMN-FOUNDATION CONNECTION THROUGH EXTERNAL SOCKET

In practice, bridge foundations and pier columns are usually constructed with cast-in-place concrete. Precast columns are currently widely used in highway bridges in China, which can save construction time and improve concrete quality. The connection between precast bridge columns and the foundation can affect how forces transfer from one to the other. This paper investigates using external sockets to form a connection between the bridge column and foundation. This method can accelerate the bridge construction time with the additional advantages of improving the orientation and creating a large erection tolerance. Two types of connections are presented and tested to investigate the behavior of the column-foundation connections and find a more suitable way to use external socket connections. The experimental results show that the column-foundation connection design satisfies the design requirements. The results also show that roughening the column surface within the external socket is more effective at connecting the column to the foundation when using an external socket compared to attaching a steel plate on the column. The experimental results are validated with a finite element analysis, resulting in a proposal regarding the column-foundation connection behavior as well as design recommendations for the external socket connection.

Investigating the effect of grain composition on the erosion around deepwater foundations with a new simplified scour resistance test

Bridges are critical nodes in the transportation system, especially those crossing wide rivers and seas. Once in service, bridge foundations and the surrounding soils will act as a system together and are subjected to erosion caused by the flows. For more than one century, researchers and engineers have made significant efforts to understand the scour process and its mechanisms to protect bridge foundations from failures. Past studies on bridge scour mainly started from treating scour a hydraulic problem and focused on the flow field due to the interactions between flow and structure. Actually, for a given flow condition, the erodibility of bed materials plays an important role for scour initiation and propagation. For this reason, this study developed a new laboratory apparatus, Simplified Scour Resistance Test (SSRT), that can quickly evaluate the erodibility properties of soil samples and assist in identifying the critical conditions for scour initiation and development. It was firstly validated by Toyoura sand samples with a median particle size of 0.17 mm. Additional tests were then conducted on samples sieved to be populated by single-size particles (d = 0.075 mm, 0.25 mm, 0.5 mm, and 2.0 mm, respectively) and four different soil mixtures under different flow conditions. Results indicate that the grain composition has a significant influence on the scour resistance, while the compaction or density has less influence than the grain size. Granular materials with the same median particle size showed very different scour resistance, i.e., well-graded samples have much higher scour resistance than poorly graded ones. Scour characteristics of the mixed soils can be related to the particle size distribution curve. With this new testing apparatus and the results obtained, a correction factor ks is proposed to improve the traditional predictive methods considering soil composition, which overcomes the limitation of traditional scour prediction methods that often only considered the median particle size, D50.

A Computational Model to Automate the Design of Reinforced Concrete Tee Beam Girder Bridge Using Python Ecosystem

The design of tee beams girder bridge members such as deck slab, main girder, and cross girder is automated by using a computation model based on the python ecosystem. The slab, main girder, cross girder section, and reinforcement detailing are generated by using the purposed computational model. The strength and serviceability checks are as per the Indian Road Congress: 112-2011, Code of Practice for Concrete Road Bridges. The model takes the design parameters of dead and live load from Indian Road Congress 5 and 6 as an input and provides structural detailing of elements involved in the tee beam girder bridge system. The validation of the model architect is performed by comparing it with the solved illustration as per the Indian Road Congress norms. The section sizes and the steel requirement is calculated efficiently and with accuracy thus the time required to generate the structural drawings has reduced drastically. Moreover, with help of the purposed model, a more intensive database of tee beam girder bridges including bridge bearings, piers and foundation can be modelled towards the automation of complete reinforced concrete bridge design as per the Indian Road Congress.

Comparison of laboratory test and in-situ test results against bored pile foundation bearing capacity at Sido Mukti II Bridge Foundation Gorontalo Province

The purpose of this study is to compare the bearing capacity of the bored pile from the results of laboratory tests and in situ tests. Soil investigations conducted in the field in the form of a Standard Penetration Test (SPT), and drilling. SPT test to obtain variations in soil density. While drilling is used to describe the soil profile at a certain depth. The research method is in the form of analysis of bearing capacity based on comparison of the results of in-situ tests and laboratory tests. Soil results from drilling are taken in 2 conditions namely disturbed conditions to describe each layer and undisturbed samples to be tested in a laboratory with a direct shear test or unconfined compressive strength. Based on the comparison of the value of the allowable bearing capacity is found that the analysis of the results of the in-situ test gives a value of the allowable bearing capacity more than the laboratory tests. This is due to the soil condition in the field at the testing experiencing compaction due to blow SPT.

Field Evaluation of Load Bearing Capacity and Embedment Depth of Existing Ballastless Plate Girder Bridge Foundations

The ballastless plate girder bridge, classified as a structure type that requires an emergent replacement among domestic railway bridges, generally tends to upgrade to a ballasted track along with continuous welded rail (CWR). The axial forces of the CWR due to the temperature change need to be distributed to the bridge foundations. Because most of the existing ballastless plate girder bridges of over 50 years of age do not provide any design information, such bridge foundations are regarded as unknown foundations, and therefore, it is crucial to identify the structural adequacy and dimension. In this study, an effort was made to establish a correlation between the standard penetration test (SPT) and mid-size pneumatic cone penetration test (MPCP) to estimate the load bearing capacity of an unknown foundation. A field test was conducted to estimate the depth of the unknown foundation by employing SPT and MPCP as the source wave part. The magnitude of the shear wave was mitigated by the presence of PVC and steel pipes, such that it might be possible to identify the embedment depth of unknown foundations.

Limitations of Sonic Echo Testing on Buried Piles of Unknown Bridge Foundations

ABSTRACT Nondestructive Sonic Echo (SE) field tests have shown that this method does not have a satisfactory performance in determining the depth of piles fully buried underneath pile caps. In the current study, we endeavored to investigate the possibility of improving SE methodology to obtain interpretable results leading to determining the depth of buried piles in such foundations. The results obtained from the investigated numerical models indicated that the location of the pile toe could be determined when the height of the pile cap is less than 1 m. However, this value is questionable since it has been concluded in the absence of surrounding soil damping. In real bridge foundations with surrounding soils, the SE method may only be able to detect the length of a pile located beneath a cap with a height significantly smaller than 1 m. In summary, our simplified models show that the SE test is not a proper method to determine the length of fully buried piles supporting caps due to the limitations and difficulties discussed in the article.

Effect of Source Application on Sonic Echo/Impulse Response Tests Applied to Steel H-Piles

AbstractThe sonic echo/impulse response (SE/IR) method is a versatile nondestructive method for evaluating the conditions of unknown bridge foundations. Previous studies have shown that the method ...