colspan不在数据表中工作？

i have a table and i'm using datatables and its working without any colspan added to it..but when i try to add a colspan on the last column the filtering, searching and pagination are all not showing..how can i supposed to work it out.please help me..

here is my code

CSS

.table_wrapper{
    margin-top:5px;
    max-width:100%;
    width:100%;
    margin-bottom:60px;
    overflow:hidden;
    -webkit-box-shadow: 0 8px 30px -6px black;
    -moz-box-shadow: 0 8px 30px -6px black;
    box-shadow: 0 8px 30px -6px black;
    border: 3px dashed red;
    height:600px;

}
.datatables{
    border-collapse:collapse;
    margin-right: auto;
    margin-left: auto;
    font-size: 13px;
}
thead th{
    background-color:#6a782a;
    color:#FFF;
    padding-left: 10px;
    padding-right: 10px;
}

tbody td{
word-wrap: break-word;
}

HTML

<div class="table_wrapper">
    <table class="datatables table-striped" width="100%">
        <thead>
             <tr>
                <th>LHID</th>
                <th>LO Name</th>
                <th>Province</th>
                <th>Municipality</th>
                <th>Barangay</th>
                <th>Title Number</th>
                <th>Lot Number</th>
                <th>Survey Number</th>
                <th>Area</th>
                <th>RLBET Action</th>
                <th>Reasons</th>
                <th colspan="2">Action</th>
            </tr>
        </thead>
        <tbody>
                <?php
                    //$query = "SELECT * FROM login";
                    echo $LTID->viewdetails();

                 ?>
        </tbody>
    </table>
</div>