2.1 工程概况
2.1.1 工程简介
2.1.2 气候条件
本合同段所处地区是沙漠气候，年降水量12mm。12月至次年3月为冬季，多北风和西北风，白天温度15度左右，夜晚温度可降至10度以下。热季从4月至11月，以东北风为特点，可能带来一些季风雨，经常引起沙暴，白天温度一般超过32度。
2.1.3 地形地质
2.1.3.1 地形
2.1.3.2 地质
根据从现场调查过程中获得的信息及业主提供的地质资料可知，沿线的地质条件如下：
风积沙（大部分可移动）（qes）：由第四纪的风积沙构成，大部分是可移动的，峰谷相连，波浪起伏。
砾石（qg2）：由片状石英砾石、各种比例的石灰石和卵石组成。
aruma 构造（ka）：这种材料主要由灰色的，棕黄色和奶油色的石灰石和次要的白云石和粘土组成。
钙质壳（qdc）：这种材料由红褐色，灰色的，棕黄色和黄色的，通常是硬的沙状的石灰石组成，常常含有夹在里面的底岩碎片。
umm er radhuma构造（tu）：这种构造由灰色的，棕黄色和奶油色的石灰石和含有白云石的石灰石和白云石构成。
沙石、泥灰岩和石灰石（tsm）：由红褐色、灰色的泥灰质的沙石，含沙泥灰岩和含沙的石灰石组成。
淤泥和沙石（qg）：主要由石灰石组成。
sabkhah 淤积（qsb）：由泥沙、粘土、含泥的沙组成，通常是含盐的。
石屑构造（td）：由粉红色、白色和灰色的泥灰岩，红绿橄榄色的粘土和少量沙石组成。
2.1.4 交通条件
本合同段沿线主要公路有：50号、85号、95号、603号、7410号及其它一些公路，路况均较好。大部分结构物集中在线路东段，进场道路较好，西段需要修建较长的施工便道。
2.1.5 材料供应
混凝土：因材料运输较为困难，搅拌站的资质审查较为繁琐，施工中尽量采用商品混凝土，沿线可在abu hadriyah、an nuayriyah、qaryah alulya、as suayyirah、ras azur、samdah等地采购商品混凝土，另在kp20+000、kp200+000附近设两座混凝土搅拌站及相应的材料库。
砂石料：除部分地段的石质挖方可资利用外，均需远运。
油料：由沿线的加油站采购。
钢材：在沿线的城市采购。
水：有条件的地方打井，其它地方采用水车运水。
电：采用自发电。
2 construction scheme and method
2.1 project description
2.1.1 project scope
there are 3 railway bridges, 11 highway bridges， 359 box culverts, 198 pipe culverts, 44 crossings, 1 station, 14.22million cubic meter railway subgrade excavation, 22.52million cubic meter railway subgrade fill and 6.2million cubic meter highway subgrade fill in ctw100 contract.。
2.1.2 climate
the contract is in desert climate, annual precipitation is 12m. winter is from december to march with north wind and north west wind and the temperater is 15 degree in day time and 10degree less in night time. the hot season is from april to november with north east wind and perhaps some monsoon and season rain and sandstorm. the temperature in day time is usually over 32 degree.
2.1.3 topography and geology
2.1.3.1 topography
2.1.3.2 geology
according to our site invesitgation and the data provided by employer, the geology along the line is as following:
sand dunes（majority is movable）（qes）：formed with blown sand of quaternary period.
gravel （qg2）: formed with slice-shape quartz gravel, limestone and pebble.
aruma constitution（ka）: majority formed with gray, brown and creamy limestone, minority with dolomite and clay.
calcium shell（qdc）：formed with henna, gray or yellow limestone, usually hard and with rock fragment in it.
umm er radhuma constitution（tu）: this structure is formed with gray, yellow or creamy limestone, limestone with dolomite and dolomite.
sand, marlite and limestone（tsm）：formed with henna, gray marly sand, marlite with sand in it and limestone.
sludge and sand（qg）：mainly formed with limestone.
sabkhah deposition（qsb）：formed with sediment, clay and clay bearing sand usually saliferous.
chips construction（td）：formed with pink, white and gray marlite, olive clay and little sand.
2.1.4 transportation
the main highways along the contract are:50#、85#、95#、60#、7410#, etc which are all in good condition. most of the structures are in the east part of the contract. the access roads are in good condition. in the west part long access roads need to be built.
2.1.5 resource of material
water: water for living will be transported long distance and water for construction will be gotten by drilling wells or transported long distance.
power: self generated
sand and stone: transported long distance besides some excavated material.
fuel: purchased at gas station along the line.
steel: purchased in cities along the line.